

Hemmi Slide Rule Catalogue Raisonné  
This Catalogue Raisonne describes every slide rule ever made by the Hemmi Slide Rule Company of Japanor at least all those I have been able to identify. It is the most comprehensive catalogue of Hemmi slide rules ever published. There are two parts: (1) THIS PAGE lists Hemmi slide rules for which a model number is known.  
(2) The SECOND PAGE (click here) contains descriptions of Hemmimade slide rules for which I have not been able to determine a model number. These are usually rules with names rather than numbers or military rules or rules sold under another company's (Post, Foxboro, SKF, etc.) name.  
Construction material is celluloid on bamboo except for model number which begin with "P" (e.g., "P23") which are all plastic and for a few rules whose substance is explicitly mentioned in the text.  
This is an updated version of the Comprehensive Hemmi Catalog which was published in the Spring 2003 issue of the Journal of the Oughtred Society. It is based upon about 500 documents, photographs and specimen slide rules, many of which were supplied by my friends in Japan: William Lise, Atsushi Tomozawa, Yukio Kubota and Hitoshi Nori; I cannot begin to express my gratitude to them. Many errors exist in spite of their efforts and this catalog remains a work in progress. I will be grateful to anyone who can supply missing information or pictures or point out errors. I am indebted to Tom Dilatush for prolonged discussions of how this information should be organized and displayed.  
Paul Ross  
Model  Dates  Front Scales  Rear and Other Calculating Scales  Body  Comment  Also Sold As  
Models118: Obsolete model numbers abandoned about 1930.  
1 1/1 
191329  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 250 x 28 x 9.5mm 
Mannheim. ("Normal") Discontinued as a Hemmi rule ca1930 but made until WWII for Post.  Tamaya 1941
(191627); HO 1768 (1914); Post 1449 (1930WWII) 

Pic  Artillery variant with minutes and mils conversion scales on bottom edge and trigonometric formulas for gunnery on back of rule. Dates probably later than model 1.  
Pic  A [B, Stadia, C] D  Stadia variant. Stadia scale (SinCos and Cos²) added to front of slide. Dates probably later than model 1.  
2  191329  Pic  Same as model 1 but with decimalindicating cursor.  Discontinued ca1930.  Tamaya 1937 (191327); HO 1767 (191428) 

3  191929  Pic  LL2, A [B, C] D, LL3  [S, L, T] (S keyed to A/B) Gutter: E, F 
//Closed 250 mm x 11/4in x 10 mm 
Electro. (Copy of Faber 378) LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No overrange. HP gauge mark (probably only 746). Single hairline. At least three different cursors. Tamaya 1905 (191927); Hemmi 80 (1930+).  
4  191929  Pic  Same as 3 but with decimalindicating cursor.  Tamaya 1904 (191627), Hemmi 81 (1930+).  
5  191929  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 500 mm x 11/4 x13/32in 
Discontinued as a Hemmi rule ca1930 but made until WWII for Post.  Tamaya
1899 (191627); HO 1772 (1928); Post 1450 (1936WWII). 

6  191429  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 125 x 24 x 9 mm 
Pocket Mannheim. Replaced by model 48 ca1930.  HO 1763 (191435); Tamaya 1942 (191627). 

7  192629  Pic  Same as 6 but with decimalindicating cursor  Tamaya 1949 (1927)  
8  191329  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 125 x 24 x 9 mm 
Extra Fine Mannheim w Magnifier.  Tamaya
1943 (191627); HO 1764 (191448) 

9  191929  Pic  Same as 8 but with magnifiying decimalindicating cursor  Discontinued ca1930.  Tamaya 1900 (191627)  
10  192629  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 250 mm 
Teninch extra fine with "extended lens" magnifier. Discontinued ca1930.  Tamaya 2148 (1927)  
11  192629  Pic  Same as10 but with decimalindicating "extendedlens" cursor.  Discontinued ca1930.  Tamaya 2180 (1927)  
12  DF [CF, CI, C] D (Folded at ?)  Blank  ? 150 mm 
Simplified Slide Rule.
Plastic. Single uncorroborated reference. 

12  192629  Pic  Same as model 3 but with "extendedlens" magnifying cursor.  Discontinued ca1930.  Tamaya 2782 (1927)  
13  192629  Pic  Same as 4 but with decimalindicating "extendedlens" cursor.  Discontinued ca1930.  Tamaya 2783 (1927)  
14  192629  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim with square edges.  Tamaya 2784 (1927); Hemmi 35 (1930+) 

15  192629  Pic  Same as 14 but with decimalindicating cursor.  Discontinued ca1930.  Tamaya 2785 (1927)  
16  192629  Pic  Same as 14 but with magnifying cursor.  Tamaya
2786. Hemmi 35ML (1930+) 

17  192629  Pic  Same as 14 but with magnifying decimalindicating cursor.  Discontinued ca1930.  Tamaya 2787  
18  192629  Pocket kit including pen, pad and model 15 slide rule.  Discontinued ca1930.  Tamaya 2788  
Model Numbers 2024 were assigned to Classroom Demo Rules before WWII; Student Rules after WWII.  
20  193237  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  Demo 2000 mm 
Demonstration Mannheim (Model 50).  Tamaya 4451 (1932)  
21  193237  K, A [B, CI, C] D, L with overrange  [S, S&T, T]  Demo 2000 mm 
Demonstration Rietz (Model 64).  Tamaya 4452 (1932)  
22  195459  Pic  [CI, C] D, A  No back  Special 200 x 23 x 9 mm 
Cheap student rule distributed in Asia only. Slide held to single stator. Sandalwood (not bamboo) with celluloid cursor.  
P23  195759  Pic  A [B, CI, C] D  Blank  Open 180 mm x1 x1/8in 
Student Mannheim w CI scale. "First plasticbased rule." 

P24  1963  Pic  DF [CF, CI, C] D, A Folded at √10.  Blank  Open 180 mm x1 x1/8in 
Student.  
24  1927  Pic  A [B, C] D  Blank  //Closed 125 x 26 x 3 mm 
Ultrathin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank. Identical to model 34 except imprinted with advertising. Rare. Appears in no known catalog.  
Models 3039: Miscellaneous four and fiveinch closed body rules  
30  1930
WWII See below 
Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim. Model number never appears on rule. Some w "SUN" cut through or "SKF" embossed into backing plate.  Tamaya 4453
(1927); Post 1447 (193133); Post 1440 (1934WWII) 

31  193039  Pic  Same as 30 but with decimalindicating cursor.  No CI scale.  Tamaya 4454  
32  1930WWII  Pic  Same as 30 but with magnifying cursor.  Tamaya 4455;
Post 1447M (193133); 1441 (1934WWII); Boston Blue Print 1441; US Blue 1888 

33  193039  Pic  Same as 30 but with decimalindicating magnifying cursor  No CI scale.  Tamaya 4456  
30R  MIOJ  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim w CI scale. No model number on rule but case and box marked "30R."  Fuji 41.  
30  1951EOB  Pic  Same rule with "R" dropped from model number on case and box. Allplastic cursor after ca 1970.  
32R  MIOJ  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 100 mm x 11/16 x 7/32 in 
Same body as 30R except with magnifier. No model number on rule but case and box marked "32R."  Post 1441(WWII1971); TP 44DA410 (1972+); HO 1760 (195264); Geo 3413405 (1964+) US Blue 1888 (MIOJ) 

32  MIOJEOB  Pic  Same rule with "R" dropped from model number on case and box. Allplastic cursor after ca 1970.  
P33S  1971  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to C/D)  Closed 125 x 28 x 5 mm 
Pocket Improved Mannheim. Allplastic version of model 34RK.  
P33 /SS 
1970EOB  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to C/D)  Closed 125 x 27 x 4.5mm 
Pocket Improved Mannheim. Unique size.  
34  1932  Pic  A [B, C] D  Blank  //Closed 125 x 26 x 3 mm 
Ultrathin all plastic with celluloid cursor. 13 cm scale on top edge; bottom blank.  Hemmi 24; Tamaya 4457 

34P  1932WWII  A [B, C] D  Blank  //Closed 125mm x 15/16 x 5/32in 
Thin Pocket Mannheim with blank back  Post 1443 (1931WWII)  
WWIIMIOJ  Pic  //Closed 125 x 26 x 5 mm 

34π  1932MIOJ  CF [DF, CI, C] D  [S, L, T] (S keyed to C/D)  //Closed 125mm x 15/16 x 5/32 in 
Thin Pocket Mannheim with folded scales  Post 1445 (1931WWII)  
MIOJ  Pic  //Closed 125 x 26 x 5 mm 

34R  193540  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 125mm x 15/16 x 1/8 in 
Thin Pocket Mannheim w CI Scale.  Post 1444 (c1935WWII); HO 1762 (1935WWII) 

195568  Pic  //Closed 125 x 26 x 5 mm 

34RK  1936EOB  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 125 x 26 x 5 mm 
Post 1444K (193770),1444(1971); TP 44DA440
(1972+); US Blue 1887 (1930s); HO 1762 (WWII64); Geo 3413425 (1964+). 

34T  193639  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 125 mm x 15/16 x 1/8 in 
Thin Pocket Mannheim. "SUN" or ASEA embossed into backing plate.  
35  1935 WWII  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 100 mm x 11/16 x 3/16 in 
Vest Pocket Mannheim with 4inch and 10cm measuring scales on square edges  Hemmi 14; Post 1437 (c1935WWII); HO 1761 (193548) 

35ML  1930s  Pic  Same as 35 but with magnifying cursor  Hemmi 16  
P35 B35 
195961  Pic  K, DF [CF, CI, C] D, A Folded at √10.  Blank  Open 115 mm x 1 x 1/8in 
Thin bamboo core (in spite of "P" prefix) coverd with PVC (not celluloid). Marks printed, not engraved as usual with celluloid over bamboo rules.  HughesOwens model illegible. (Some with Hemmi factory model error "B35") 

P35S  1971  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [LL1, LL2, LL3]  Closed 125 x 28 x 4.6mm 

36  1936WWII  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B)  Closed 125 mm x 3/4 x 7/32 in 
Narrow Pocket Mannheim w CI scale. Measuring scales on BACK of rule.  Post 1438 (c1935WWII)  
P36 P36S 
196670  Pic  D [Conversion gauge marks, A] D  Instructions [Conversion gauge marks, B] Instructions  Open 115 mm x 1 x 1/8in 
Rule is labeled "P36;" box and instructions "P36S." Set arrow on slide opposite value on top D scale; converted value appears on bottom D scale opposite corresponding arrow. Reverse slide for more conversions. Markings and instructions in Japanese.  
P37  196670  Pic  (1), (2), D [C, CI, B] MD1, MD2  [B, PR1, PR2, PR3]  Closed 125 x 28 x 4.6mm 
SALES. Labeled in Japanese. MD1 is months and days from 1/1 to 6/30, MD2 from 7/1 to 12/31. PR123 = three short profit ratio scales. Slide must be reversed to read. {Two hairlines: D: 1.2}.  
P39  K, A, DF [CF, CIF, CI, C] D, DI, L (Folded at ?)  [B, TI, SI, C]  Closed 125 mm 

Models 4049: Basic Mannheim Rules (A [B, C] D) before WWI and "Improved" Mannheim (A [B, CI, C] D, K) after WWII.  
40  1932MIOJ  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 250 x 28 x 8 mm 
Tamaya 4458 (1927), Post 1446 (193149); HO 1768 (193548); Boston Blue Print 1446; US Blue 1876 (1930s); Lietz 2974N (1930s).  
41  193239  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 125 mm 
Pocket Mannheim. No measuring scales  Tamaya 4459 (1932)  
42  1932  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 250 x 28 x 8 mm 
Model 40 w measuring scales on BACK.  Tamaya 4460 (1932)  
43  1932  Same as 42 but with decimalindicating cursor.  Tamaya 4461 (1932)  
44  1932  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  Closed 125 mm x 15/16 x 1/4in 
No slant; cm & inch scales on back of rule.  Tamaya 4462 (1932)  
45  1932  Same as 44 but with decimalindicating cursor.  Tamaya 4463 (1932)  
45  194968  Pic  DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Closed 200 x 28 x 8 mm 
Student. Quite different from 1932 model 45.  
46  193640  Pic  A [B, C] D  Blank  Special 125mm x 1 in 
"Cardboard covered in transparent celluloid with leather sheath."  
47  1936WWII  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 250x28 x 8 mm 
Thin successor to model 1/1.  Post 1449T (1937WWII)  
48  193240  Pic  A [B, C] D  [S, L, T] (S keyed to A/B)  //Closed 125 mm x 15/16 x 1/4 in 
Pocket Mannheim. Thin successor to model 6.  
40F  1968  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Closed 250 x 28 x 8 mm 
Fuji 85.  
40RK  194969  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  Closed 250 x 28 x 8 mm 
Improved Mannheim. ("Slide Rule with CI and K Scale" in early lit)  Post 1447
(c19491971); HO 1768C (195264); Geo 3413526 (196471); US Blue 1877 (1940s?) 

1972EOB  Pic  Same as preceding but wider with thick plastic back  Closed 250 mm x 11/4 x 9/32 in 
TP 44BA470
(1972+); HO 3413526 (1972+) 

P 40RK 
196769  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  Open 250 x 28 x 8 mm 
AllPlastic Improved Mannheim. Hard plastic case.  Post
1447P (c1967); Geo 3413530 (c1967) 

43A  196171  Pic  A [B, CI, C] D, K  [T, L, S] (S keyed to C/D)  Closed 200 x 28 x 8 mm 
Student Improved Mannheim.  
P43D  1973EOB  Pic  A [B, CI, C] D, K  [T, L, S] (S keyed to C/D)  Closed 200 x 28 x 6.4mm 
Like 43S except no indices on back of rule; slide must be reversed.  
P43S  1969  Pic  A [B, CI, C] D, K  [T, L, S] (S keyed to C/D)  Closed 200 x 28 x 6.4mm 
Plastic version of 43A. Indices for reading trig scales on back of rule.  
45K  1962EOB  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Closed 200 x 28 x 8 mm 
Post 1445 (c196671); TP 44BA450 (1972+); Geo 3413500 (1967+). All have scales folded at π. 

P45K  196568  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Open 200 x 28 x 5 mm 
Open body allplastic version of 45K  Post 1445P (1965) has scales folded at π.  
P45D  1973EOB  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [T, L, S]  Closed 200 x 28 x 6.4mm 
"Junior High School Students." Like P45S except trig scales not inverted and no indices on back of rule; slide must be reversed.  
P45S  1969EOB  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Closed 200 x 28 x 6.4mm 
Closed body allplastic version of 45K. Simpler construction than P45K.  
Models 5059: "Improved" Mannheims (A [B, CI, C] D, K and [S, L, T]) and variants  
50 50/1 50/3 
193251  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 250 x 28 x10.5mm 
Improved Mannheim. Formerly model 102.  Hemmi 102; Tamaya 4464 (1932); Post 1452 (c193551); HO 1771
(192848); US Blue 1880 (1930s) 

50F, 50/1F  1936MIOJ  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  //Closed 250 x 28 x 8 mm 
Thin version of 50, 50/1 but accepts standard cursor.  Post 1452T (1936WWII)  
50/1π  1936WWII  Pic  A, DF [CF, CI, C] D, L Folded at π.  [S, S&T, T]  //Closed 250 x 28 x10.5mm 
Post 1455 (c1935WWII)  
50W  1951EOB  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D)  //Closed 250 x 34 x 11 mm 
Wide Improved Mannheim.  Post
1452W ('5170), 1452 ('71); TP 44BA520 ('72+); HO 1771 ('5164); Geo 3413215 ('64+) 

P50  1965?68?  A [B, CI, C] D, K  Blank  Open? 250 mm x 11/2 in 
Improved Mannheim  
5020  1935WWII  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  //Closed 500 x 34 x 11 mm 
Long Improved Mannheim. Made for Post & HO only; not sold as Hemmi brand.  Post 1454 (1936WWII); HO 1772 (193558) HO 3413235 (1969) 

WWII1969  Pic  //Closed 500 x 40 x 12 mm 
Wide Long Improved Mannheim. Hemmi & Post brands. {Three Hairlines: D: C, C}.  
51/1, 51/3  193239  Pic  Same as 50/1, 50/3 but with decimalindicating cursor.  //Closed 250 x 28 x10.5mm 
Formerly model 103.  Tamaya 4466, 4467 (1932)  
52  1932WWII  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B)  //Closed 125 mm x 15/16 x 11/32in 
Thicker than 34R  Tamaya 4468; Post 1448 (193637) 

53  193239  Pic  Same as 52 but with decimalindicating cursor.  Tamaya 4469 (1932)  
54  1936WWII  Pic  A [B, CI, C] D, K with overrange  [S, L, T] (S keyed to A/B)  //Closed 150 x 26 x 6 mm 
Extra Fine Improved Mannheim with magnifying cursor.  Post 1453 (c1935WWII)  
55  193639  Same as 54 but without magnifying cursor  
Models 6079: Rietz Rules ( K, A [B, C] D, L and [S, S&T, T] )  
60/1, 60/3  193239  Pic  K, A [B, C] D, L  [S, S&T, T]  //Closed 250 mm x 11/4 x 13/32in 
Rietz. Single line model 60/1 discontinued ca 1930.  Tamaya 4470, 4471 (1932)  
193940  Pic  K, A [B, C] D, L with overrange  
61/3  193239  Same as 60/3 but with decimalindicating cursor.  
62/3  1932  K, A [B, C] D, L  [S, S&T, T]  //Closed 150 mm 
Extra Fine Rietz.  Tamaya 4472, 4473 (1932)  
63/3  1932  Same as 62/3 but with decimalindicating cursor.  
64, 64/1, 64/3  193268  Pic  K, A [B, CI, C] D, L with overrange  [S, S&T, T]  //Closed 250 x 34 x 11 mm 
"System Rietz." {64/3 hairlines: D: C, C} Some w 13013 cm on bottom. Probably without overrange before 1935.  Tamaya 4474 (1932)  
64T  1965EOB  Pic  K, A [B, BI, CI, C] D, DI, L with overrange  [T2, T1, ST, S]  //Closed 250 x 34 x 11 mm 
Super Rietz. {3 hairlines: D: C, C}.  
65  193240  Pic  Same as 64/3 but with decimalindicating cursor.  //Closed 250 x 34 x 11 mm 
Tamaya 4475 (1932)  
66  193268  Pic  K, A [B, CI, C] D, L with overrange  [S, S&T, T]  //Closed 150 x 26 x 9 mm 
Extra Fine Improved Rietz. {3line cursor: D: C, C} Some 808 cm on bottom.  Tamaya 4476 (1932)  
66F  1932?40  Pic  Same as 66 but thin.  
67  193240  Same as 66 but with 3line magnifying cursor.  Tamaya 4477 (1932)  
68  193240  Same as 66 but with 3line decimalindicating cursor.  Tamaya 4478 (1932)  
69  193240  Same as 66 but with 3line decimalindicating magnifying cursor.  Tamaya 4479 (1932)  
70  193240  Pic  K, A [B, CI, C] D, L with overrange  [S, S&T, T]  //Closed 500 x 34 x 12 mm 
Long Improved Rietz. {3 hairlines: D: C, C}.  Tamaya 4480 (1932)  
1951EOB  Pic  //Closed 500 x 40 x 12 mm 

72  196671  Pic  K, DF [CF, CIF, CI, C] D, A with overrange Folded at √10  [TI2, TI1, L, SI]  //Closed 500 x 40 x _ mm 
"Precision Slide Rule for Practical Engineers." Single hairline.  
74  1937EOB  Pic  K. A [B. CI. C] D, L with overrange  [S, S&T, T]  //Closed 125 x 26 x 5 mm 
Pocket Improved Rietz. {3 hairlines: D: C, C}.  
Models 8089: "Electro" Slide Rules  
80 80/1 80/3 
193132  LL2, A [B, C] D, LL3 No overrange  [S,
L, T] (S Keyed to A/B) Gutter: E, F 
//Closed 250 x 34 x 11 mm (wider than model 3) 
Electro. LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No overrange. Hp gauge mark  Hemmi
3; Tamaya 4481, 4482 (1932); HO 1770 (1928c50); Post 1456 (c1934WWII) 

193233  Pic  LL2, A [B, CI, C] D, LL3 No overrange  Like preceding except CI scale added.  
193436  [S, L, T] (S Keyed to A/B) Gutter E, F 
Like preceding except no W mark, E, F scales close together in gutter.  
193652  Pic  LL2, A [B, CI, C] D, LL3 with overrange  Like preceding with overrange scales.  
81/1, 81/3  192839  Pic  Same as 80/1, 80/3 (4 variantsdepending upon date mfd) but with decimalindicating cursor.  //Closed 250 x 34 x 11 mm 
Hemmi 4; Tamaya 4482, 4484 (1932) 

82  193237  Same as 80/1 except short.  //Closed 125 x _ x 9 mm 
Tamaya 4485 (1932)  
83  193237  Same as 82 but with decimalindicating cursor.  Tamaya 4486 (1932)  
84  1932  Same as 82 but with magnifying cursor.  Tamaya 4487 (1932)  
85  1932  Pic  Same as 82 but with magnifying decimalindicating cursor  Tamaya 4488 (1932)  
85  MIOJ  Pic  db, Neper, A [B, CI, C] D  [TI2, TI1, L, SI1]  //Closed 250 x 34 x 11 mm 
{3 hairlines: A: C^{2}, 1.307} (Why 1.307?) Not electro, therefore model number 85 is inappropriate.  Rare.  
80K  1953EOB  Pic  E, F, A [B, CI, C] D, LL2, LL3 with overrange  [S, L, T] (S keyed to A/B) Bottom Edge: K 
//Closed 250 x 34 x 11 mm 
Electro. K scale on bottom edge; no scales in gutter. No hp mark but different cursors avail for British/US and French/Metrc HP. {3line cursor: A: hp, C^{2}}.  
86/3  193640  LL2, A [B, CI, C] D, LL3 with overrange  [S, L, T] (S keyed to A/B) Gutter: E, F 
//Closed 150 x 26 mm 
Extra fine Electro. Hp gauge mark. No W mark. E,F scales close together in gutter. {Three hairlines: A: hp, C^{2}}.  
86/3K  1950  Pic  LL2, A [B, CI, C] D, LL3 with overrange 
[S, L, T] (S keyed to
A/B) Gutter: E, F Bottom Edge: K 
//Closed 150 x 26 x 8 mm 
Same as model 86/3 except K scale added to bottom edge.  
86  1951  Identical to and contemporaneous with model 86/3K.  
86K  1954EOB  Pic  E, F, A [B, CI, C] D, LL2, LL3 with overrange  [S, L, T] (S keyed to A/B) Bottom Edge: K 
//Closed 150 x 26 x 8 mm 
Extra Fine Electro. No scales in gutter, no hp mark. {Three hairlines: A: hp, C^{2}}.  
87/3  193639  Same as 86/3 but with magnifying cursor.  //Closed 150 x 26 mm 

Models 9099: Stadia Slide Rules  
90  193239  Pic  L, D [M1, M2, C] D, A with overrange  [S, S&T,
T] Bottom Edge: K, IA 
//Closed 250 x 34 x _ mm 
Stadia. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to rightmost hairline.  
90A  1940  Same as 90  
90B  1939?  Pic  Same as 90 but using "centesimal
degrees." (100 centesimal degrees = right angle) 
First of a proposed series (models 90B, 91B, 2690B) of centesimaldegree stadia rules. Models 91B and 2690B never manufactured.  
91  193239  Pic  Same as 90 but with decimalindicating cursor  //Closed 250 x 34 x _ mm 
Tamaya 4490 (1932)  
91A  1939?  Same as 91.  "91A" used to distinguish this rule from proposed centesimal degree model 91B.  
92  193239  Pic  L, D [M1, M2, C] D, A  [S, S&T, T] Bottom Edge: K, IA 
//Closed 150 x 26 x 9.6mm 
Extra Fine Stadia. Two calculating scales on bottom edge. {3 hairlines: D: C, C}.  Tamaya 4491 (1932)  
93  193239  Pic  Same as 92 but with magnifying cursor.  Tamaya 4492 (1932)  
94  193239  Same as 92 but with decimalindicating cursor.  Tamaya 4493 (1932)  
95  193239  Same as 92 but with decimalindicating magnifying cursor.  Tamaya 4494 (1932)  
96  193639  Pic  L, D [M1, M2, C] D, A with overrange  [S, S&T, T] Bottom Edge: K, IA 
//Closed 500 x 34 x 11 mm 
Long 90. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to center hairline.  
Model Numbers 100107 were assigned to new rules developed in 192627; replaced by modern numbering system about 1930.  
100  192627  Pic  A [B, CI, C] D  [S, L, T] (S keyed to A/B)  //Closed 250 mm 
Short lived.  Tamaya 2790 (1927)  
101  192627  Pic  Same as 100 but with decimal indicating cursor.  Tamaya 2791 (1927)  
102  192628  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to A/B)  //Closed 250 x 28 mm 
Improved Mannheim. Model number changed to 50/1 ca 1928.  Tamaya 2792 (1927), HO1771 

103  192628  Pic  Same as 102 but with decimalindicating cursor.  Model number changed to 51/1 ca 1928.  Tamaya 2793, (1927)  
104  1927  LL2, A [B, CI, C] D, LL3 No overrange  [S, L, T] (S keyed to A/B) Gutter: E, F 
//Closed 125 mm 
Pocket Electro. LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No overrange. Hp gauge mark.  Hemmi
82; Tamaya 2994 (1927) 

105  1927  Same as 104 but with decimalindicating cursor.  Hemmi 83, Tamaya 2995 

106  1927  Same as 104 but with magnifying cursor.  Hemmi 84, Tamaya 2996 

107  1927  Same as 104 but with magnifying decimalindicating cursor.  Hemmi 85, Tamaya 2997 

Models 100109: Large Classroom Demonstration Rules  
100  195468  Pic  DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Demo 1000 mm 
Demonstration version of model 45.  
100K  1971?  K, DF [CF,CI, C] D, A Folded at √10.  [TI, L, SI]  Demo 1000 mm 
Demonstration version of model 45K  
101  195468  l, A [B, CI, C] D  [S, K, T] (S keyed to C/D)  Demo 1000 mm 
Demonstration version of model 2640.  
101A  1967EOB  Pic  A [B, CI, C] D, K  [S, L, T] (S keyed to C/D)  Demo 1000 mm 
Demonstration version of models 40RK & 43A.  
102  195468  CI, C, [D, A]  Blank  Demo 1000 mm 
Demonstration version of model 22.  
103  195968  K, DF [CF, CIF, CI, C] D, A Folded at √10.  [TI1, TI2, L, SI]  Demo 1500 mm 
Demonstration version of model 2664S.  
104  1959  Demo 1000 mm 
Demonstration  
107  1971?  LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.  K, A [B, TI1, TI2, SI] D, DI  Demo 1000 mm 
Demonstration version of model P253.  
108  1971?  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at√10  K, A [B, TI, SI, C] D, DI, L  Demo 1000 mm 
Demonstration version of model 254W.  
Models 110129: Reserved for Specialty Rules but Hardly Used  
110  193740  Pic  LL2, A [B, CI, C] D, LL3 with overrange  [S, S&T,
T] Bottom Edge: K 
//Closed 250 x 34 x 11 mm 
Mechanical/ Electrical. K scale on bottom edge. {Three hairlines: D: C, C}.  
120  1939  Pic  L, K, A [B, CI, S1, T1, C] D,SΘ with overrange 
[LL3, LL3, LL2, LL2, LL1, LL1] Bottom Edge: GΘ (2 scales) 
//Closed 250 x 34 x 11 mm 
"MIGHT." Listed without description by Katsunori Kadokura (Chronology of Japanese Hemmi Slide Rules, Journal of the Oughtred Soc, Vol 1, No 2, August 1992). Pictured specimen identified as Model 120 by Yukio Kubota, March 2014.  
DP121  1968  Projectn 305X182 X 12 mm 
Described in manual for DP122 (below) as projection rule for model P253.  
DP122  1969  Pic  K, A, DF [CF, CIF, CI] D, DI, L  K, A, DF [B, CTI2, TI1, SI, C] D, DI, L  Projectn
305X182 X 12 mm 
Overhead projection rule for models 2662 and 2664S. Sold with five masks for obscuring irrelevant scales.  
Models 130139: Darmstadt (L, K, A [B, CI, C] D, Cos, Sin, Tg and [LL1, LL2, LL3]) and Variants  
130  195168  Pic  L, K, A [B, CI, C] D, Cos with overrange  [LL1, LL2,
LL3] Bottom Edge: SIN tg 
//Closed 250 x 34 x 11 mm 
Darmstadt. S and T scales on bottom edge of
rule. {3 hairlines: D: hpC, C}. 

130W  1970EOB  Pic  T, K, A [B, BI, CI, C] D, P, S with overrange  [L, LL0, LL1, LL2, LL3]  //Closed 250 mm x 11/2 x 7/16 in 
Advanced Darmstadt.
Unique width. {3 hairlines: A: C^{2}, hpC^{2}}. 

135  195971  Pic  T, K, A [B, CI, C] D, P, S with overrange  [L, LL1, LL2, LL3]  //Closed 125 x 26 x 5 mm 
Pocket Darmstadt. {3 hairlines: D: hpC, C}. 

P135k  2005  Pic  T, K, A [B, CI, C] D, P, S with overrange  [L, LL1, LL2, LL3]  Closed 200 x 32 x 4.3mm 
Darmstadt. Only 250 made. Manufactured in 2005 to specs of ISRG and Japanese collectors and sold by subscription.  
136  195168  Pic  L, K, A [B, CI, C] D Cos with overrange  [LL1, LL2, LL3] Bottom Edge: SIN tg 
//Closed 150 x 26 x 8 mm 
Extra Fine Darmstadt. D scale is labeled "SIN" other scales not labeled.  
Models 140149: Pocket Duplexes  
140  MIOJ  Pic  DF [CF, CI, C] D, L Folded at √10.  A [B, TI, SI, C] D, DI  Duplex 150 mm x 13/16 x 1/4 in 
Hemmi's first "pocket" duplex. Body is short version of old narrow model 150.  
P141  1960EOB  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π  T, S, U, P [Q, c, V, R] A q, n, L  Duplex 125 x 34 x 4 mm 
Toyo Carrier Corp for air conditioning duct design. Marked "'Carrier' Ductuler." Solid plastic stators but same size and cursor as bamboo 149A.  
143  1968  Pic  P1, P2, DF [CF, CIF, CI, C] D, LL (2 scales. One has second calibration for %) Folded at 3.6  A, N [M, £, S/d, C] D, G  Duplex 125 x 34 x 4 mm 
"Commerce." N, M have 365 division for dates. £, S/d = pound, shilling/pence. G is a set of conversion gauge marks.  Pocket version of Hemmi model P263.  
149  1959  Pic  LL/1. LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  L, K, A [B, TI, SI, C] D, LL0, LL/0  Duplex 125 x 34 x 4 mm 
"Pocket 259D" but actually closer to 259 with TI, SI instead of T, S, ST. Hemmi name on back of rule. Bare bamboo edges.  
149A  1960EOB  Pic  Same as 149 except celluloid veneer covers edges.  
P149A  1976?  Pic  LL/1. LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π  L, K, A [B, TI, SI, C] D, LL0, LL/0  Duplex 125 x 36 x 4 mm 
All plastic. About 10 mm longer overall and 2 mm wider than bamboo 149A.  
Models 150300: Ten and TwentyInch Duplex and Open Body Rules  
150  1925WWII  Pic  DF [CF, CIF, C] D Folded at π.  K, A [B, S, T, CI] D, L  Duplex 250 mm x 13/16 x 1/4 in 
Hemmi's first duplex (but Hemmi called early models 150, 152, 153 and 154 "Universal," not duplex.) Copied from K&E 40883 whose narrow width it shares.  Tamaya 4497
(1932); Post 1458 (c1931WWII); HO 1765 (1935WWII); US Blue 1881 (1930s): Lietz 3054L (1930s) 

MIOJ  Pic  Duplex 250 mm x 15/8 x 1/4 in 
Standard width. Replaced by model 250.  HO 1765 (WWIIc49)  
152  192548  Pic  K, A [B, CI, C] D, T  Θ, R_{θ,} P [Q, Q', C] LL3, LL2, LL1  Duplex 250 mm x 15/8 x 1/4 in 
Electrical Engineer's Universal (Duplex). Often no model number. Some marked "US Pat 1459857." (Issued to O D Parsons in 1923 for P, Q scales.)  Tamaya 4498 (1932); Post 1459 (c1933WWII); HO 1766 (193548); US Blue 1889 (1930s) Lietz (1930s)  
153  193168  Pic  L, K, A [B, CI, C] D, T G_{θ}  Θ, R_{θ} P, [Q, Q', C] LL3, LL2, LL1  Duplex 250 mm x 15/8 x 1/4 in 
Electrical Engineer's Universal (Duplex). Some (c1938) with stator screws on back of rule. US Patent 2079464, May 4, 1937.  Post 1461 (c1933WWII); US Blue 1893 (1030s) 

154  192568  Pic  DF, P', P [Q, CF, CI, S_{θ}^{o}] A, D, K Folded at π.  S_{χ}, T_{χ}, T_{θ} [Th, Sh, Sh C] D, L, χ  Duplex 500 mm x 13/4 x 1/4 in 
Electrical Engineer's Universal (Duplex) 20." Two cursors. Early have scale letters eteched on cursor glasses.  Tamaya 4499 (1932); Post 1460 (c1933WWII) 

155  WWII1951  Pic  K, A, DF [CF, B, CI, C] D, L Folded at √10.  Sh1, Sh2, Th1 [TI2, TI1, SI1, C] D, DI  Duplex 250 mm x 15/8 x 1/4 in 
General Engineering with Hyperbolic Scales. Replaced by model 255.  
157  WWII1950  Pic  K, A, DF [CF, B, CI, C] D, L Folded at √10.  LL/1, LL/2, LL/3 [TI2, TI1, SI1, C] LL3, LL2, LL1  Duplex 250 mm x 15/8 x 1/4 in 
General Engineering with LogLog Scales.  
159  194952  Pic  T, DF [CF, CIF, CI, C] D, S, ST Folded at π.  LL0, LL00, A [B, K, L, C] LL3, LL2, LL1  Duplex 250 mm x 15/8 x 1/4 in 
Replaced by model 259 c1951.  Post 1462H "POSTRIG" (c1949 51), replaced by Post 1460 "VERSALOG" (Hemmi 258) 

160  1951  Pic  Nomogram1(α=0.05), χ^{2}, A [B, CI, C] D, φ, ax  P, F'1 [F'2, a'] A, χ^{2}, ,Nomogram2(α=0.01)  Duplex 250 mm x72.5mm 
Inductive Statistics. Almost three inches wide! Stator with nomograms is about 46 mm wide. Allplastic cursor similar to Relay/Ricoh.  
165  1953  Duplex 250 mm x _ 
Statistical Sampling. No slide, just many short scales and a cursor.  
190  193940  Pic  K, A [B, R2, R1, C] D, DI  [SI2, SCI2, SI1, SCI1] Bottom Edge: L 
Closed 250 x 40 x 11 mm 
"Precision Stadia" {3 hairlines: D: C, C}. Left half of SCI1 scale is inverse cos^{2}. 

200  193668  Pic  D6, D5, D4 [C6, C5, C4, C3, C2, C1] D3, D2, D1  DF6, DF5, DF4 [CF6, CF5, CF4, CF3, CF2, CF1] DF3, DF2, DF1 Scales folded at ^{12}√10.  Duplex 400 mm x 13/4 x 1/4 in 
Precision Duplex. (Originally known as "Ultra accuracy.") Four digit precision. Scales are cut into six segments, each 400 mm long. Early production has scale labels in green on cursor. U S Patent 2235106A, March 18, 1941.  
201  196768  Pic  L2.4, L1.3, A2.4, A1.3 [C4, C3, C2, C1] D1, D2, D3, D4  K4, K3, K2, K1 [CF4, CF3, CF2, CF1] DF1, DF2, DF3, DF4 Scales folded at ^{8}√10.  Duplex 500 mm x 13/4 x 1/4 in 
"Sold in Japan." Early production has scale labels in green on cursor.  
250  1950EOB  Pic  DF [CF, CIF, CI, C] D, L Folded at √10.  K, A [B, TI1, TI2, SI] D, DI  Duplex 250 mm x 15/8 x 1/4 in 
General Engineering and Business. Replaced models 150 and 2600. Most with usual German silver end brackets but a few (<10) specimens with anodized black end brackets are known.  
251  195158  Pic  L, DF [CF, CIF, CI, C] D, DI Folded at π.  K, A [B, T, S, ST, C] D, LL3, LL2, LL1  Duplex 250 mm x 15/8 x 1/4 in 
Mechanical Engineer.  
1958EOB  Pic  L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  K, A [B, T, S, ST, C] D, DI  HO 1773  
P253  1961EOB  Pic  LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded at √10.  K, A [B, TI2, TI1, SI] D, DI  Duplex 250 x 41 x 5 mm 
"Vectolog." Elaborate clamshell case. Allplastic version of model 264.  HO 177400
(1964); Geo 3413130 (1964+) 

254W  196466  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10.  K, A [B, TI, SI, C] D, DI, L  Duplex 250 mm x 13/4 x 1/4 in 
"High School Students". Basis for model 108 demo rule. Equal length stators  
1969EOB  Pic  Traditional stators.  
254 WS 
1970s  Pic  Same as above and below. But folded at π. 
K, A [B, TI, SI, C] D, DI, L  Only difference from 254W above is where front scales are folded.  Only one specimen known, date code "UB" = Feb 1970.  
1970s  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10.  K, A, [SIN COS, COS^{2}, TI, SI, C] D, DI, L  Stadia scales on rear but marked 254WS on front.  Equal stators date = "OC"; others = "UB" or no code.  
1971  Pic  K, A [B, TI_{2}, TI_{1}, SI, C] D, DI, L  Duplex 250 mm x 13/4 x 1/4 in 
"High School Students." Traditional stators. Hemmi name on back of rule.  
1970s  Pic  Same. But folded at π.  KI, K, AI, A [B, S, T, CI, C] D, Ldb, P, DI  May set a record for number of different inverse scales on one side of a rule.  
254 WN 
1972EOB  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10  LL/0, K, A [B, TI2, TI1, SI, C] D, DI, L, LL0  Duplex 250 mm x 13/4 x 1/4 in 
"High School Students." Traditional stators. Hemmi name on back of rule.  
254 WNS 
1972  Pic  Same. Folded at π.  
255  195057  Pic  L, K, DF [CF, CIF, CI, C] D, χ, θ Folded at π.  Sh1, Sh2, Th, A [B, TI2, TI1, SI, C] D,LL3,LL2,LL1  Duplex 250 mm x 13/4 x 1/4 in 
Expert Electrical Engineer. Replaced model 155.  
195862  Pic  L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Sh1, Sh2, Th, A [B, TI2, TI1, SI, C] D, χ, θ  
255D  1963EOB  Pic  L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Sh1, Sh2, Th, A [B, TI2, TI1, SI, C] D, DI, χ, θ  
256  195068  Pic  L/dB, Neper, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  A, Ĺ [Ċ, SI, TI] D, l, F  Duplex 250 mm x 13/4 x 1/4 in 
Electrical Communications. Ĺ, Ċ are L and C with dot over; these scales are about half length.  
257  195268  Pic  L, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Ch AM, Ch NZ, M1 [M2, ^{o}F, ^{o}C, ^{o}K, F(t)] Kg/cm^{2}, mm Hg, in Hg Vac, tw  Chemical Engineer.  Post 1491 (c1957c67); HO 1770 (1958) 

257L  1971EOB  Pic  L, K, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Ch AM, Ch NZ, M1 [M2, ^{o}F, ^{o}C, ^{o}K, LM] mm Hg, Kg/cm^{2}, in Hg Vac, tw  Chemical Engineer. Hemmi name on back of rule.  
258  1951  Pic  LL0, LL/0, K, DF [CF, CIF, CI, C] D, R1, R2, L Folded at π.  LL/1, LL/2, LL/3 [T T, SecT ST, Cos S, C] D, LL3, LL2, LL1  Duplex 250 mm x 13/4 x 1/4 in 
VERSALOG Ia. About 30 specimens explicitly marked "Hemmi 258" are known. All are also marked "THE FREDERICK POST CO. NO 1460" or "THE HUGHES OWENS CO. LIMITED NO. 1777." Hemmi name on back of rule.  Post 1460 Versalog (1951+); HO 1777 Versalog (1951+). For information about Versalog II slide rules see the second page of this Catalogue Raisonne. 

259  195058  Pic  L, K, DF [CF, CIF, CI, C] D, LL/0, LL0 Folded at π.  LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1  Duplex 250 mm x 13/4 x 1/4 in 
Expert Mechanical Engineer. Replaced model 159.  
195863  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π  L, K, A [B, T, S, ST, C] D, LL0, LL/0  Expert Mechanical Engineer. Hemmi name moved to back of rule.  
259D  1953EOB  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π  L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0  
259 DS 
1970s  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  LL0, LL/0, K, A [B, T, S, ST, C] D, √1, √2, L  Duplex 250 mm x 13/4 x 1/4 in 

260  1964EOB  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L  Duplex 250 mm x 13/4 x 1/4 in 
Advanced Engineer. {3 hairlines: A: C^{2}, hpC^{2}} Some rules c1970 have brand and model on bottom edge. Some marked UNIVERSITY on bottom edge.  
260  1964  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  LL/0, LL0, K, A [B, T, S, ST, C] D, DI, P, L  Duplex 1500 mm x _ 
Painted wood classroom demonstration rule. Cursor is single wire.  
P261  1965EOB  Pic  LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  T, ST, K, A [B, BI, CI, C] D, L, P, S  Duplex 250 x 46 x 5 mm 
Advanced Engineer (Darmstadt). Stators white or pale blue. {4 hairlines on back of cursor. A: C^{2}, hpC^{2}, D: C}  TP 1420 (c1971 only) TP 44CB200 (1972+) Geo 3413660 

P262  1965EOB  Pic  LL01, LL02, LL03, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  K, A, R1, R2 [T2, T1, ST, S, C] D, L, LL00, LL0  Duplex 250 x 46 x 5 mm 
Advanced Engineer (Rietz).  TP 1422 (c1971 only), TP 44CB220 (1972+) 

P263  196567  Pic  P1, P2, DF [CF, CIF, CI, C] D, LL (2 scales. One has second calibration for %) Folded at 3.6  A, N [M, £, S/d, C] D, G  Duplex 250 x 41 x 5 mm 
"Commerce." N, M have 365 divisions for dates. £, S/d = pound, shilling/pence. G is a set of conversion gauge marks .  Geo 3413155 (1967+) Hemmi 143 is pocket version. 

264  1968EOB  Pic  LL3, LL2, DF [ CF, CIF, CI, C ] D, L, LL1 Folded at √10.  K, A [B, TI2, TI1, SI] D, DI  Duplex 250 mm x 15/8 x 1/4 in 
Bamboo version of model P253, Vectolog.  
264S  1969  Pic  Same as 264 except CIF scale is green.  Only specimen is owned by Mitsuru Itoh. Date code "TB."  
264S  1970s  Pic  LL3, LL2, DF [ CF, CIF, CI, C ] D, L dB, LL1 Folded at √10.  K, A [B, TI2, TI1, SI] D, DI, χ, θ  Duplex 250 mm x 15/8 x 1/4 in 
Same as 264 except with χ and θ scales and 0  20 dB markings added to L scale.  
P265  1968EOB  Pic  P1, P2, DF [CF, CIF, CI, C] D, LL2, LL1 Folded at 3.6  A, D [G, 024, N] M, 024  Duplex 250 x 46 x 4 mm 
"Business." N, M have 365 divisions for dates. G is a set of conversion gauge marks. Instructions, scale labels in Japanese.  
266  1961EOB  Pic  LL/3 (and LL/1), LL/2, LL2, A [B, BI, CI, C] D, dB L, S, T  X_{L}, X_{C}, F, r_{1 }(and P) [r_{2} (and Q), L, C, C_{Z}] L, Z, f_{o }(and l)  Duplex 250 mm x 13/4 x 1/4 in 
"Electronics." Announced in 1961 but not in Hemmi catalogs until 1966. Early specimens (1962) marked "Developed by SONY." LL/3, LL/1, r_{1}, r_{2,} P, Q are partial length scales. Also sold as Geo 3413550 (1966+)  
P267  1971EOB  Pic  ³√3, ³√2, ³√1, DF [CF, CIF, CI, C] D, √1, √2, δ(unif.) Folded at √10  ^{4}√4, ^{4}√3, ^{4}√2, ^{4}√1 [λ_{δ}(conc), λ_{δ}(Trape), λ_{M}, P] Q, L, T, S  Duplex 250 x 46 x 5 mm 
"Structural Design"  
269  1965EOB  Pic  L, F, K, A [B, K', CI, C] D, LL3, LL2, LL1  CL, SL, M, TL [R, ST, T, S, C] D, DI, SinCos1, SinCos2  Duplex 250 mm x 13/4 x 1/4 in 
Civil Engineer.  
P270  1971EOB  Pic  J, J [T(ºK), Q(m³/s), Q(m³/s)] Hm(m), Q(m³/s), Ht(m)  X, X, Cz, Cmax(PPM) [He(m), Cy, CI, C] D, A, L  Duplex 250 x 46 x 5 mm 
"Pollution A." (air quality analysis) 19 scales in black red and blue.  
P271  1974EOB  Pic  x,x_{s}(g/kgDA), (ice), T_{φ,}t_{φ}(ºC), [h_{w},h_{s}(mmhg), CI, C] D, v,v_{a}(m^{3}/kgDA), t(ºC), t(ºF)  [t(ºC)(ice), t'_{2.5}, t(ºC)]  Open 250 x 46 x 5 mm 
Moist air. There are 13 scalesmost with complicated labels.  
274  1974EOB  Pic  L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at √10  K, A [B, TI2, TI1, SI, C] D, DI  Duplex 250 mm x 13/4 x 1/4 in 
Late model general engineering rule with scales folded at √10 and trig scales inverted. Likely sold only in Japan.  
275  195058  Pic  L, K, DF [CF, CIF, CI, C] D, c, q Folded at π.  Sh1, Sh2, Th, A [B, TI1, TI2, SI, C] D,LL3,LL2,LL1  Duplex 500 mm x 13/4 x 1/4 in 
20inch Version of Model 255.  
195863  Pic  L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Sh1, Sh2, Th, A [B, TI2, TI1, SI, C] D, χ, θ  20inch Version of Model 255. Some w green scale labels on cursor.  
275D  1963EOB  Pic  L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  Sh1, Sh2, Th, A [B, TI2, TI1, SI, C] D, DI, χ, θ  20inch Version of Model 255D. Some w green scale labels on cursor.  
279  195058  Pic  L, K, DF [CF, CIF, CI, C] D, LL0, LL/0 Folded at π.  LL/1, LL/2, LL/3, A [B, T, S, ST, C] D, LL3, LL2, LL1  Duplex 500 mm x 13/4 x 1/4 in 
20inch Version of Model 259. Some w green scale labels on cursor.  
195863  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  L, K, A [B, T, S, ST, C] D, LL0, LL/0  
279D  196368  Pic  LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL Folded at π.  L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0  20inch Version of Model 259D. Some w green scale labels on cursor.  
P280  1959EOB  Pic  T, K, A [B, CI, C] D, L, S, ST  [LL1, LL2, LL3]  Open 250 x 46 x 4 mm 
Beginners.  TP 1414 (c1971 only), 44BB140 (1972+); Geo 341 3645  
280S  1976?  Pic  L, K, A [B, CI, C] D, S, ST, T  cm [LL1, LL2, LL3] inches 
Open 250 mm 
All plastic. Marked "HEMMI, JAPAN, 280S" but probably made by D&P in Germany. Only known specimen found in Thailand.  Same as Aristo 0903 except back of Aristo slide is blank.  
P281  1970EOB  Pic  T, K, A [B, CI, C] D, L, S, ST  Blank  Open 250 x 46 x 4 mm 
Rietz.  TP 1410 (c1971 only), 44BB100 (1972+); Geo 341 3640  
P283  197071  Pic  K, A, DF [CF CI, C] D, L, T, S Folded at π.  [LL1, LL2, LL3]  Open 250 x 46 x 4 mm 
Beginners.  
300  WWII  Pic  G, E [F, CI, C] D, M  [Blank]  //Closed 250 x 34 x 8.5mm 
Decimal Calendar Rule. G scale is folded at 365; E & F folded at 3.042 = 365/12. M scale is set of gauge marks for Japanese weights & measures. Japanese language.  
Models 301999: Specialty Slide Rules  
301  195466  Pic  t, ω [CI, f, P, C] D, A, db  [θ, θd, g', g]  //Closed 250 x 34 x 11 mm 
Control Engineering. Four cursors! 301A is transparent overlay for 301.  Post 1490 (1957ca67)  
305  195970  Pic  TmV/S, l_{1} [l_{2}, m, a] T, n  [N, F t, 6u]  //Closed 125x26 x _ mm 
Acoustic Design. Patent 225936, 225937.  
400  195968  Pic  Y, A [B, CI, C] D, LL3, LL2, LL1  Ebeta, R(AI), Dist, Dose Rate, S, Isotopes (4 scales)] Egamma, Pb, Fe, Al  Duplex 250 mm x 13/4 x 1/4 in 
Radioisotope Engineering.  
401  1966  Pic  d, W [Nt, D, MI, M] L  t_{0}, P [d, D, D, Na( δ)] k(P), d  Duplex 250 mm x 15/8 x 1/4 in 
"Coiled Spring Rule"  
P402  196668  Pic  15 scales in black, red, blue and green  all labeled in Japanese. Only three scales are full length. Scale arrangement and range of variables differs slightly between the two models.  A, DF [CF, CIF, CI, C] LL (2 scales) Folded at √10.  Duplex 250 x 41 x 5 mm 
Tanabe Corporate Performance Analysis combines ten measures such as Marginal Profit Ratio and Total Equity Growth into a single corporate performance score.  Click here for an illustrated explanation of models P402 and P403 by Atsushi Tomozawa.  
P403  196668  Pic  P402 implements this technique for manufacturing businesses; P403 is for wholesale and retail distributors. Rule and instructions in Japanese.  
405  195859  Pic  C_{2}F, Al_{2}O_{3} [Fe_{2}O_{3}, C_{2}AF] C_{2}A, SO_{3}, CaSO_{4}  C_{2}S (A Scale), CaO [SiO_{2}(for C_{3}S), Fe_{2}O_{3}, SiO_{2}(for C_{2}S), SO_{3}/Al_{2}O_{3}] C_{3}S, C_{2}S (B Scale)  Duplex 250 mm x 13/4 x 1/4 in 
Cement Composition. Scale labels are chemical symbols, numbers subscripted. No scales are logarithmic. Fe_{2}O_{3} and SiO_{2}(for C_{2}S) are separate short scales on same line. Instruction Manual published by Portland Cement Assoc. Skokie, Ill, May 1959.  
410  195968  Pic  G_{2}, G_{1}, F_{2}, F_{1} [χ, F_{1}G_{1}] Z_{1}+Z_{2}, G', F'  G_{2}, G_{1}, F_{2}, F_{1} [χ, CI, C] D, A  Duplex 250 mm x 13/4 x 1/4 in 
Involute of Gear Wheel.  
451  Pic  LL/3, LL/2, LL2, A [B, BI, CI, C] D, dB L, S, T  Eight specialized scales, center scales are not full length.  Duplex 250 mm x 13/4 x 1/4 in 
Marked "Field Intensity" on back.  
P452  1968EOB  Pic  LL1, LL2, LL3, CR DF [T CF, CIF, % CI, T C] R D, L, in, cm (Folded at π)  ST, 3n2 K, 2n1 A [B, BI, CI, C] D, P, S, T  Duplex 250 x 46 x 4 mm 
Business. Some marked "System H. Kroon." Yellow slide, green brackets. (Post & TP have blue slide & brackets)  TP 1426 (c1971 only), 44CB260 (1972+) 

500  125 mm x _ 
Single uncorroborated reference.  
640S  1972  Pic  K, DF [CF, CIF, CI, C] D, A, L Folded at √10.  [STI, TI2, TI1, SI, CI]  //Closed 250 x 45 x 9 mm 
Desk Rule Bamboo between thick plastic.  
641  1975  Pic  K, A, DF [CF, CIF, B, CI, C] D, DI, L Folded at √10.  [STI, TI2, TI1, SI, CI]  //Closed 250 x 45 x 9 mm 
Desk Rule. Bamboo between thick plastic.  
642T  1973  Pic  K, A [B, BI, CI, C] D, DI, L with overrange  [T2, T1, ST, S]  //Closed 250 x 45 x 9 mm 
Desk version of 64T. Bamboo between thick plastic. {3 hairlines: D: C, C}.  
651  1969  Pic  K, A, DF [CF, CIF, B, CI, C] D, DI, L Folded at √10.  [TI2, TI1, STI, SI, C]  //Closed 250 mm x 11/2 x 7/16 in 

Models 1xxx: Circular Slide Rules  
1001  1971+  Pic  A, D, C, CI, L  Blank  Circular 80 mm 
Circular.  Geo 3413910  
1002  1971+  Pic  A, D [C, CI]  Blank  Circular 80 mm 
Circular. Less elaborate than 1001.  
2600 Series Rules Introduced in 1940 (February 11, 1940 was the 2600th Aniversary of the Founding of Japan)  
2600  194051  Pic  DF [CF, CI, C] D, L Folded at √10.  K, A [B, TI2, TI1, SI1] D, DI  Duplex 250 mm x 15/8 x 1/4 in 
General Engineering and Business.  
2634  1949EOB  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI2, TI1, L, SI]  //Closed 125 x 26 x 5 mm 
Pocket 2664.  
P 2634 
Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI2, TI1, L, SI]  Closed 125 mm x _ 

2640  194968  Pic  l, A [B, CI, C] D  [S, K, T] (S keyed to C/D)  Closed 200 x 28 x 8 mm 
Beginners Slide Rule for 50W. Plastic cursor.  
2641  Pic  DF [CF, CI, C] D, A Folded at √10.  Blank  Closed 200 x 28 x 8 mm 
Beginners Slide Rule for 45 (which, itself, was a beginner's rule). Plastic cursor.  
2645  WWII  Pic  DF [CF, CI, C] D, A Folded at √10.  [TI, L, SI]  Closed 200 x 28 x 8 mm 
Essentially identical to model 45 except CI scale is black.  Only one specimen known.  
2662  1966?69?  Pic  K, A, DF [CF, CIF, CI, C] D, DI, L Folded at √10.  [B, TI, SI, C]  //Closed 250 x 34 x 11 mm 
Some with 13013 cm scale on bottom.  See Hemmi Catalogue Raisonne 2 for a slide projector version of this rule.  
2664  WWII  Pic  K, DF [CF, CI, C] D, A+L Folded at √10.  [TI1, TI2, SI2, SI1]  Closed 250 x 34 x 9 mm 
Wartime construction (bare vertical edges and back) No model number on rule. A+L scale is left half of A scale joined to right half of L scale.  
MIOJ  Pic  //Closed 250 x 34 x 11 mm 
Better quality construction (slanted top edge, bottom vertical edge and back all covered with celluloid.)  
194958  Pic  K, DF [CF, CI, C] D, A Folded at √10.  [TI2, TI1, L, SI1]  Full length A scale. Full length L scale replaces SI2.  
2664S  195868  Pic  K, DF [CF, CIF, CI, C] D, A Folded at √10.  [TI2, TI1, L, SI]  //Closed 250 x 34 x 11 mm 
Same as 2664 except 10 mm longer overall and green CIF scale added.  
2664 SS 
1967EOB  Pic  K, A, DF [CF, CIF, CI, C] D, DI Folded at √10.  [TI2, TI1, L, SI]  //Closed 250 x 34 x 11 mm 
Same as 2664S except DI scale added.  
2670  MIOJ  Pic  K, A [B, CI, C] D, L  [S, S&T, T]  //Closed 500 x 40 x 12 mm 
Long Rietz. Shortlived replacement for model 70. {3 hairlines: D: C, C}.  
2690  195168  Pic  L, D [M1, M2, C] D, A  [S, S&T, T]  //Closed 250 x 34 x 11 mm 
Stadia. {3 hairlines: D: C, C}.  
2690A  195455  Same as 2690  "2690A" used to distinguish this rule from proposed centesimal degree model 2690B.  
Click here for Hemmi Cat IIthe table of Hemmi rules which had no model number.  
Click here for Frederick Post Slide Rule Cross Reference  
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