Nordic Slide Rules
from Denmark and Sweden

KEEP ISRM FREE!
Donations are
tax deductable

Letter to Marvin Clarence from the Queen of Denmark in support of ISRM

This gallery is dedicated to Danish and Swedish slide rules and manufacturers of that region.
It is unknown if Finland ever made or rebranded a slide rule for their market.
Manufacturers/Brands Represented: CARID - Denmark, DIWA - Denmark, Norden - Sweden, Teknor - Sweden, UTO - Denmark, J.H. Weil - Denmark, X-Act - Denmark.

Denmark

CARID #3000 Log Log Decitrig Duplex
REF

CARID #3000 Log Log Decitrig Duplex
Made in Denmark - Identical to DIWA No.911
Construction note: Celluloid laminated wood stock. Cursor design and lens retention is similar to early Dietzgen duplexes
Front Scale: L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2
Back Scale: LL0, LL00, A [ B, T Cot, ST, S Cos ] D, DI, K
Archive - Steve Seale Collection, Nashville, Tennessee.

DIWA - Dansk Industri for Waterpasser A/S (Danish Industry for Levels Ltd.). Was a Danish manufacturer of slide rules in gentofte, Denmark. DIWA originally began in 1854, starting as a small general store, supplying farmers in the region with a variety of items such as paint, cigars, wine, photographic equipment, tapestry, etc. In 1873 Ove Nielsen purchased the store and enlarged the business selling fuel. The third generation of Nielsens developed the area with housing, many shops, factories and a cinema. In 1924 they began making of slide rules and measuring devices in a small shop to the Danish market and to other Scandinavian countries. By 1940 they moved totally out of retailing to becoming full-time manufacturers of spirit-levels and slide rules eventually becoming Europe's leading firm in spirit-level manufacturing supplying more than half of all spirit-levels used in England. Because of war shortages, slide rule manufacture became increasingly important to their business with a 16 year partnership with Kruuse and Larsen, DIWA had experience in the complicated wood work and Kruuse/Larsen had their knowledge on scale dividing which was the basis for their collaboration.Kruuse and Larsen later went their own way and founded the company UTO. After WWII, 16 models were produced, and exported. Some sold through a Lawes Rabjohns Catalog. Students at the university and teachers' colleges in Denmark were required to use the Rietz-Ideal slide rule. Supplier to India brand Deeva. In the late 1980's the DIWA slide rules were sold by LINEX. All slide rule manufacturing stopped in the 1990's. DIWA no longer exists as a company.

Diwa No. 14
ISRM 14.01.10.29

Diwa No. 14
Made in Denmark - Metal and plastic. (Note cursor similar to early Dietzgen)
Front Scale: LL01, K, B [ A, T Cot, ST, S Cos, S ] D, L, LL1
Back Scale: LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2

Diwa Log Log 101
ISRM 13.10.09.01

wood clamshell case

Diwa Log Log 101 - c1948
Made in Denmark - Wood w/Plastic laminate
Note 1: 'Railroad Track' style divisions engraved on 'DIWANYL' plastic facings.
Note 2: Beautiful wood clamshell box with use care instructions on both sides.
Front Scale: 10in // LL2, A [ B, CI, C ] D, LL3 || K
Back Scale (window)
[ S, S&T, T ]
Back: Equivalents
Cursor: 3 hairlines, extended to side (for K scale)

Gift of Phillip Rodley of UpperHutt, New Zealand
This slide rule and others in the ISRM archives and galleries were donated through the generosity and support of Phillip Rodley. Phil is very enthusiatic in finding slide rules in New Zealand that are not available to the rest of the world, and gifting them to ISRM. He enjoys the American brands that have leather sleeves and belt loops.

Diwa No.111 Electro
ISRM 14.01.03.08

Leather sleeve

Also stamped inside flap of sleeve is 'LEES (W) LT^D 1943'. Lees (W) ltd. is a company located in Walsall, UK, which made wholesale leather products for firms like Diwa. It is still in business..

Diwa No.111 Electro - 1943-1950
Made in Denmark - Wood w/Plastic laminate screwed to stock.
Front Scale: 10-1/4inch // LL2, A (Kw) [ B (mm2)(H.P.), C (Watt) ] D, LL03 || K
Well: Motor TL=%, Volt
Back Scale (window)
[ S, S&T, T ]
Back: Equivalents (English)
Cursor: 3 hairlines on top, one on bottom edge
Original Owner: M.P. Armstrong. Etched on bottom of stock, written in manual and inside flap of sleeve.
Gift Of Phillip Rodley of UpperHutt, New Zealand

Instructions (4.29MB PDF)

M.P. Armstrong, most likely an electrical engineer, worked at Reyrolle in 1950 and later, A. Reyrolle & Co. had a New Zealand division, called Reyrolle Pacific.

A. Reyrolle & Co. was a British engineering firm based in Hebburn, Tyne and Wear in the North East of England. The company was founded by Alphonse Constant Reyrolle, a Frenchman, in 1886 at Fitzroy Square in London to produce scientific instruments. He moved the business to Hebburn on Tyneside in 1901. For many years the company was one of the largest employers on Tyneside. The New Zealand division, Reyrolle Pacific, was sold by Siemens AG/VA Tech to a private individual in New Zealand. This included the switchgear factory in Petone, with a staff of about 100. Reyrolle Pacific Switchgear became RPS Switchgear and manufactures retrofit breakers for the original LMT switchgear, and vacuum breakers and panels for 11 kV substations.

Diwa No.111 Electro
ISRM 21.08.12.10

Diwa No.111 Electro - 1971
Made in Denmark - Wood w/Plastic laminate screwed to stock.
Front Scale: 27cm // LL2, A (10Amp)(Kw) [ B (10m, 10mm²)(H.P.), CI, C (Watt) ] D, LL3 || K
Well: Motor, Volt
Back Scale (window)
[ S, S&T, T ]
Back: Equivalents (English)
Cursor: 3 hairlines on top, one on bottom edge
Original Owner: D.C. Meyer. written on inside flap of sleeve.

Leather sleeve

Diwa 201 Technical
REF

Diwa 201 Technical - c1955
Made in Denmark - Wood w/Plastic laminate
Front Scale: 25cm // K, A [ B, CI, C ] D, L
Back Scale (window)
[ S, S&T, T ]
Back: Equivalents
Cursor: 3 hairlines
Archive Herman van Herwijnen's SR Catalogue

Diwa No.301 Commercial
ISRM 13.07.03.23

Diwa No.301 Commercial
Made in Denmark - Wood with Plastic laminate, rivet and screw reinforcement
Note: Railroad track style divisions
Front Scale: A [ B, CI, C ] D
Back Scale:[ S, S&T, T ]
Back: Equivalents
Cursor: 3 hairlines
Gift of Daniel Swerdlow, Bethesda, Maryland.

Diwa No.301 Log Log
ISRM 19.09.30.01

Diwa No.301 Log Log - date code 75 (July 1955)
Made in Copenhagen, Denmark - made of DIVINYL Plastic laminated wood.
Note: Railroad track style divisions
Front Scale: 25cm, 10in // L, K, A [ B, CI, C ] D, LL3, LL2, LL1
Back Scale: [ S, S&T, T ]
Back: Equivalents (English)
Cursor: 3 hairlines
Original owner: Alan E. Perry (imprinted on stock and written on sleeve flap). Research(?): Alan E. Perry (1938-2013), born in New London, CT, graduated from New London High School and UCONN and enlisted in the US Air Force.. He married Madeline (Kutschirek) who predeceased him in 2003. Alan went to work for Boeing in Washington State. He later worked at United Nuclear in Montville, CT until his retirement.
Gift Of Sarah Coury of Sarasota, Florida

English Instructions (10.3MB PDF), Leather sleeve

Diwa No.301 Rietz
ISRM 14.01.03.02

Diwa No.301 Rietz - date code 36 (March 1956)
Made in Copenhagen, Denmark - made of DIVINYL Plastic laminated wood.
Note: Railroad track style divisions
Front Scale: 25cm, 10in // A [ B, CI, C ] D
Back Scale: [ S, S&T, T ]
Back: Equivalents (English)
Cursor: 3 hairlines
Gift Of Phillip Rodley of Upperhutt, New Zealand

English Instructions (10.3MB PDF), Box end,
Use and Care Insert (in Danish/English/German/French/Spanish)

Diwa No.301 Rietz (German version)
ISRM 11.11.18.01

Diwa No.301 Rietz - Date Code 37 (March 1957)
Made in Copenhagen, Denmark - made of DIVINYL Plastic laminated wood.
Front Scale: 25cm, 10in // K, A [ B, CI, C ] D, L
Back Scale (window)
[ S, S&T, T ]
Back: Equivalents (German)
Cursor: 3 hairlines

Diwa 311 Electro
REF S315

Diwa 311 Electro - Closed simplex
Made in Copenhagen, Denmark - made of DIVINYL Plastic laminated wood.
Front Scale: 25cm, 10in // Dynamo/Motor, K, A(kW) [ B(hp), CI, C ] D, Volt, tg ctg, cin cos
Back Scale (window)
[LL1, LL2, LL3 ]
Back: Equivalents
Cursor: 4 hairlines

Diwa Rietz-Ideal No. 1-1
ISRM 17.05.02.59

Diwa Rietz-Ideal No. 1-1
Made in Denmark - All Plastic
Front Scale: 25cm/10in // L, K, A [ B, CI, C ] D, S, ST, T
Back Scale: Blank
Cursor: 3 hairlines
Original Owner: Albolm Skole
Gift Of Mike Weaver, UK

Diwa No. 501 Rietz
REF

Diwa No. 501 Rietz
Made in Denmark - All Plastic
Front Scale: 27cm // K, A [ B, CI, C ] D, L
Back Scale: S, S&T, T
Cursor: 3 hairlines
Original Owner: Ir. Albert Kartahardja (1928-2017) of Bandung, Indonesia.
Scan provided by Marvin Clarence, the grandson of Albert Kartahardja

Ir. Albert Kartahardja was born on 18 June 1928 in Batavia. He was a Civil Engineering Engineer who studied at the Faculteit van Technische Wetenschap, Universiteit van Indonesie te Bandoeng (Faculty of Engineering Sciences, University of Indonesia in Bandoeng), class of 1947. On 1 November 1960, he founded the Faculty of Engineering at Universitas Katolik Parahyangan (Parahyangan Catholic University) alongside Prof. Ir. A.M. Semawi, Ir. Tjan Kwie Nio and Ir. Dr. M.A. Sosrowinarso. Ir. Albert Kartahardja served as Director of the Institute for Research on Problems in Building Construction - Department of Public Works, under the then Minister Prof. Dr. Soetami and Dr. Purnomosidi Hardjisarosa. Apart from his main occupation, he also served as a Lecturer at Unpar (Parahyangan Catholic University), and as Assistant Dean for Civil Engineering, Academic Affairs (1979-1983). He has written many books and articles on settlements and building issues and was one of the leading technology experts in Indonesia. He died on 1 April 2017 in Bandung.

601/631 Instruction Sheet

Diwa 601 Rietz
ISRM 22.03.01.103

Diwa 601 Rietz
Made in Denmark - Metal cursor blocks, Plastic lens.
Front Scale: 5in // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back Advertising: PSC Applied Research Limited, Toronto, Canada
Gift Of Philip E. Stanley

Diwa 601-1 Rietz V1 Promo: Components Inc., Arizona Div.
ISRM 12.06.24.35

Diwa 601-1 V1 Rietz Promotional - dc294
Made in Denmark - All Plastic - Note 25mm wide Cursor, double bend spring.
Front Scale: 5.5in // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back Advertising: Components Inc., Arizona Div.
Donated by the Anonymous Collector and daughter.

Diwa 601-1 Rietz V2 Promo: Fansteel
ISRM 15.07.20.07

Diwa 601-1 V1 Rietz Promotional - no Date Code
Made in Denmark - All Plastic - Note: 22mm narrow cursor, single bend spring.
Front Scale: 5.5in // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back Advertising: Fansteel, North Chicago, Illinois.
Belonged to: R.W. Kratz
Donated by son, Nick Kratz, Pasadena, California

Diwa 601 Rietz - Lear Jet promo c1963
ISRM 20.04.01.054

Diwa 601 Rietz - Lear Jet promo c1963
Made in Denmark - No "Diwa" on stock.All 23mm Plastic cursor. spring captured outside of lens.
Front Scale: 5in // K, A [ B, CI, C ] D, L
Back Scale: 13cm [ S, S&T, T ]
Cursor: multiple hairlines
Back Advertising:Lear Jet
Gift of Philip E. Stanley, Worcester, Mass.

Diwa 601-1 Rietz V1 Promo: ITT Cannon Electric
ISRM 14.10.15.06

Diwa 601-1 V1 Rietz Promotional - dc276
Made in Denmark - All Plastic - Note: wide 25mm cursor double bend spring.
Front Scale: 5.5in // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back Advertising: ITT Cannon Electric
Gift of Edward Wright, Odenton, Maryland.

Diwa 601-1 Rietz V2 Promo: Grundfoss Bjerringbro Pumpefabrik
ISRM 12.06.24.36

Diwa 601-1 Rietz V2 Promotional - dc012
Made in Denmark - All Plastic
Front Scale: 11cm, 4.5inch // K, A [ B, CI, C ] D, L
Back Scale: [ S, ST, T ]
Cursor: 3 hairlines
Back Advertising: Grundfoss Bjerringbro Pumpefabrik A/S (Pump Fabricators)
Donated by the Huang Collection and daughter.

Diwa 601-1 Rietz V2 Promo: Engineers Scientists Guild at Lockheed
ISRM 14.07.02.98

Diwa 601-1 Rietz V2 Promo: Engineers Scientists Guild at Lockheed
Made in Denmark - All Plastic
Front Scale[extended]
11cm, 4.5inch // K, A [ B, CI, C ] D, L
Back Scale: [ S, ST, T ]
Cursor: 3 hairlines
Back Advertising: Engineers Scientists Guild, Lockheed Section
Gift of Ed Millis, Dallas, Texas.

Diwa 611 Electro Pocket
ISRM 12.03.02.16

Diwa 611 Electro Pocket
Made in Denmark - All Plastic
Front Scale: 13cm // Cos1, A(Kw) [ B(HP), CI, C ] D, Cos2
Back Scale: [ S, S&T, T ]
Well scale: Dyn-Mot, V
Cursor: 3 hairlines
Back Advertising: POHJOISMAINEN SÄHKÖ-OSAKEYHTIÖ
Donated by Richard Davis, Las Vegas, Nevada

Diwa 621 Technical 13cm Pocket Slide Rule
ISRM 20.04.01.281

Diwa 621 Technical 13cm Pocket Slide Rule
Made in Denmark - All Plastic. Instructions in English and German.
Front Scale: 13cm // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back: Diwa manufacturing Logo
Gift of Philip E. Stanley, Worcester, Mass.

Diwa 631 Commercial 11cm Pocket Slide Rule
ISRM 20.04.01.281

Diwa 631 Commercial 11cm Pocket Slide Rule
Note: Standard Rietz Scales like a 601, but instructions sgive it a "Commercial;" model suffix.
Made in Denmark - Metal Edge cursor Instructions in English and German..
Front Scale: 11cm, 4-1/2inch // K, A [ B, CI, C ] D, L
Back Scale: [ S, S&T, T ]
Cursor: 3 hairlines
Back: Hume Pipes
Gift of Philip E. Stanley, Worcester, Mass.

Diwa 641 Business Slide Rule
ISRM 20.04.01.427

Diwa 641 Business Slide Rule
Made in Denmark - All Plastic
Front Scale: 13cm // KZ [ T, Val(P%), E, T] V(Z)
Back Scale: Blank
Cursor: single hairlines
Back: Hume Pipes
Gift of Philip E. Stanley, Worcester, Mass.

Diwa Ideal No. 701 Export
ISRM 13.09.24.01

Diwa Ideal No. 701 Export
Made in Denmark - All Plastic, with blue highlight on stock.
Front Scale: L, K, A [ B, CI, C ] D, S Cos, ST Arc, T Cot
Back Scale: 25cm, DF [ CF, C ] D, 0-8 inch, 8-0 inch
Cursor: 4 hairlines
Donated by Mikael Seierup, Denmark. Belonged to his father.

Diwa 710 Teknilog
REF

Diwa 710 Teknilog - Duplex
Made in Denmark
Front Scale: LL00, ST, T, DF [ CF, CIF, CI, C ] D, P, S, LL0
Back Scale: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1
Cursor: 5 hairlines
Archive - Marion Moon Collection

Diwa 720 Polylog
ISRM 12.06.24.19

Diwa 720 Polylog - date code 320
Made in Denmark
Front Scale: LL00, L, K, A [ B, S, ST, T, C ] D, DI, P, LL0
Back Scale: LL01, LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2, LL1
Cursor: 5 hairlines

Donated by the Huang Collection and daughter.
The collector, who prefers to remain anonymous, obtained a B.S. degree in Physics from Taiwan's National Tsing Hua University in 1971. His love for computation has encouraged him to build a collection of slide rules, HP and TI calculators, as well as abaci, many displayed at ISRM.

Diwa No. 730 Combilog
REF

Diwa No. 730 Combilog
Made in Denmark
Front Scale: T1, T2, A [ B, BI, CI, C ] D, P, S, ST
Back Scale: LL1, LL2, LL3, DF [ CF, CIF, CI, C ] D, L, K
Cursor: 5 hairlines
Archive - photos from Elena Diana Perucca, Argentina.

Diwa No.741 Businessman Export
ISRM 20.10.21.01

Diwa No.741 Businessman Export
Made in Denmark
Front Scale: A, DF [ CF, B, %, CI, C ] D, K, L
Back Scale: 25cm [ blank ] 0-8in, 8-0in
Cursor: 4 hairlines
Gift Of Judith Harris of Bording, Denmark.

DIWA Darmstadt No. 851/4 Pocket Duplex
ISRM 12.11.20.02

DIWA Darmstadt No. 851/4 Pocket Duplex
Made in Denmark by DIWA
Front Scale: K, A [ B, CI, C ] D, P \\ 11cm 4in
Back Scale: L, S Cos [ LL1, LL2, LL3 ] D. T Cot
Mulitiple hair-lined cursor
Donated by Ron Dies,Vancouver, British Columbia, Canada
Ron Dies purchased and used this slide rule (see also his Hughes-Owens 1771 slide rule in the Hemmi gallery) when he was studying architecture from 1956-1962 at the University of Manitoba in Winnipeg. He used these slide rules until electronic slide rules became more useful in his career. He is currently owner of Ron Dies Architecture in Vancouver and is near retirement.

Diwa No.901 Log Log Duplex Decitrig
ISRM 20.08.07.01

Diwa No.901 Log Log Duplex Decitrig
Made in Denmark (closely resembles early Dietzgen patents and construction)
Material: Laminated wood with metal braces. Flat glass lens clamped in place.
Front Scale: LL0, LL00, A [ B, T Cot, ST, S Cos, C ] D, DI, K
Back Scale: L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2
Original owner: Marked M.J.Williams, CH (ChristsChurch) on flap
Donated by Phillip Rodley, Upperhutt, NZ

Diwa No.911 Log Log Deci-Trig Duplex
ISRM 09.01.12.93

Diwa No.911 Log Log Deci-Trig Duplex - Version 1
Made in Denmark (closely resembles early Dietzgen patents and construction)
Material: Laminated wood with metal braces.
Front Scale: LL0, LL00, A [ B, T Cot, ST, S Cos, C ] D, DI, K
Back Scale: L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2

Donated by David Hecht, Alexandria, Virginia
David's first SR was a circular Pickett 101-C, which he acquired in high school. His interest led his parents to give him a K&E 68-1210 as a graduation gift. After college, David worked fifteen years for the U.S. Navy as a contracting officer and is now retired from Civil Service. His slide rule collection specializes in Picketts and he enjoys traveling to board game conventions. Member of the Oughtred Society. Donor of numerous slide rules to ISRM and its SR Loaner Program.

Diwa No.911 Log Log Deci-Trig Duplex
ISRM 21.08.12.11

Diwa No.911 Log Log Deci-Trig Duplex - Version 2
Made in Denmark (closely resembles early Dietzgen patents and construction)
Note: Diwa Logo moved to end of slide.
Material: Laminated wood with metal braces.
Front Scale: LL0, LL00, A [ B, T Cot, ST, S Cos, C ] D, DI, K
Back Scale: L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2

Diwa No.913 Log Log Deci-Trig Duplex
ISRM 21.08.12.12

Diwa No.913 Log Log Deci-Trig Duplex
Made in Denmark - Same scale set as No.914
Material: Laminated wood with metal braces.
Front Scale: LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1
Back Scale: LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2

Diwa No.914 Log Log Deci-Trig Duplex
ISRM 21.08.07.12

Diwa No.914 Log Log Deci-Trig Duplex
Made in Denmark - Same scale set as No.913
Material: Laminated wood with metal braces.
Front Scale: LL01, K, A [ B, T Cot, ST, S Cos ] D, L, LL1
Back Scale: LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2
Gifted by William Lisowski of Pennsylvania.
Original Owner: T.P. Markle (written onn sleeve)

Norden

Norden Pocket
ISRM 20.04.01.402

Norden Pocket
Made in Sweden, It appears to use a Bruning 2401 stock
Front Scale
14cm // K, A [ B, CI, C ] D, L \\ sin cos
Back Adv: SKF
Back Scale: [ Log, tg ctg, P ]
Gift Of Philip Stanley Collection

TEKNOR

Not much is known about this brand of slide rule, and whether or not it was distributed out of the USA, UK or Europe. The specimen shown in this gallery was obviously made in Japan by Uchido Yoko, Co (was Hemmi) which mas an OEM for re-branded slide rule catalog distributors. Other re-branded models with the Teknor label were made by UTO in Denmark such as the UTO 930U Poly-e. An ebay search reveals these other models:
TEKNOR NO.1055 Grundskola (Elementary School in Swedish) Slide Rule
TEKNOR No.1061 Högstadium (High School in Swedish) Slide Rule
So the distributor is determined to have been in Sweden.

Need TEKNOR No.1055 Grundskola Slide Rule or image
TEKNOR No.1061 Högstadium Slide Rule REF: Need specimen	Need TEKNOR No.1061 Högstadium Slide Rule Made in Japan for Swedish Distributor TEKNOR (by Uchida Yoko, Co) Note: Unusual scale arrangement with two Sin/Cos scales. Front Scale: 25cm, DF [ S Cos, CI, C ] D, A, K Back Scale: T1, T2 [ CF, CIF, CI, C ] D, P, S Cos Cursor: Multiple Hairlines Archive photo
TEKNOR No.1081 Gymnasium ISRM 12.03.02.08	TEKNOR No.1081 Gymnasium Made in Japan for Swedish Distributor TEKNOR (by Uchida Yoko, Co) Note: Exactly the same as Technical Sales 1081 TechLog Emblem Series Front Scale: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 Back Scale: T2, T1, ST, DF [ CF, CIF, CI, C ] D, P, S Cos Cursor: Multiple Hairlines Donated by Richard Davis, Las Vegas, Nevada

UTO, Including HOFFMAN branded models

UTO - Fabrikken UTO out of Vonge, Denmark founded by Kal Kruuse and Poel Larsen after breaking away from DIWA, in 1957, a 16 year partnership. Kruuse and larsen had invented a logarithmic dividing (engraving) machine which had prompted DIWA to hire them in 1941. The UTO chracters do not stand for anything, but were chosen because this name could be pronounced very easily in America as well as in Japan. Hoffman, presumed to be a German distributor, appears on many of the model UTO 601 pocket slide rules. UTO slide rules are still made to this day. "The UTO SR's made now are silk screen printed on hard white PVC sheets, 7 - 9 bodies on a sheet, and machined to final shape. The cursors are injection molded of acrylic. The grooves for sliding the cursor are positioned to prevent the cursor to touch the SR surface. The printing ink bonds chemically to the PVC surface." ^{Courtesy of John Kvint, of UTO}. UTO board of Directors Poel Larsen, Kal Kruuse,and Hans Jorgenson can be seen in this Danish newspaper article and the ladies in the UTO Factory Floor. ^{courtesy of IJ Schuitema}.
For additional models made by UTO see Herman's Slide Rule Catalogue , UTO Sub-list

UTO No. 1 Studium ISRM 09.01.12.125	UTO No. 1 Studium Made in Denmark Front Scale: A, DF [ CF, CIF, CI, C ] D, K Back: Blank Donated by David Hecht, Alexandria, VA
UTO 503 Studium ISRM 09.01.12.126	UTO 503 Studium Made in Denmark Front Scale: 27cm // L, K, A [ B, CI, C ] D, ST, T, S Back: Blank Donated by David Hecht, Alexandria, VA
UTO 561 Studium ISRM 09.01.12.127	UTO 561 Studium Made in Denmark Front Scale: 27cm // L, A, DF [ CF, CI, C ] D, ST ST, T Cot, S Cos Back: Blank Cursor: 3 Hairlines Donated by David Hecht, Alexandria, VA
UTO 601 Rietz - Hoffman - Metal Cursor V1 ISRM 22.03.01.100	UTO 601 - Hoffman - Metal Cursor blocks V1 Note" Flat plastic lens and metal blocks. Made in Denmark, Distributed by Hoffman, USA Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Slide: [ S, S&T, T ] Back Adv: Industrial And Engineering Chemistry Gift of Philip E. stanley of Worcester, Mass.
UTO 601 Rietz (Yellow Slide) Convex Lens V2-cm ISRM 22.06.01.04	UTO 601 Rietz (Yellow Slide) Convex Lens V2-cm Note: Molded convex lens. Variations 2 Made in Denmark Front Scale: 13cm // K, A [ B, CI, C ] D, L Back Scale: [ S, S&T, T ] Back Adv: NORTH Gift Of Ron Gribnitz.of South Africa. Belonged to father.
UTO 601 Rietz (Yellow Slide) Convex Lens V2-in ISRM 14.10.15.05	UTO 601 Rietz (Yellow Slide) Convex Lens V2-in Note: Molded convex lens. Variations 2 Made in Denmark Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Scale: [ S, S&T, T ] Back Adv: NORTH Gift of Edward Wright, Odenton, Maryland.
UTO 601 Rietz - Hoffman - CELCO Promo ISRM 21.06.10.41	UTO 601 Rietz - Hoffman - CELCO Promo Made in Denmark, Distributed by Hoffman, USA Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Scale: [ S, S&T, T ] Back and sleeve Adv: Constantine Engineering Laboratories Co. Gift of Bob Dehn collection.
UTO 601 Rietz Hoffman V2 Cursor ISRM 14.01.10.05	UTO 601 Rietz Hoffman V2 Cursor Made in Denmark Front Scale:> 5inch // K, A [ B, CI, C ] D, L Back Scale: [ S, S&T, T ] Back Adv: Raymond Concrete Pile Division Gift of Bill Wehrend Collection, Palo Alto, California.
UTO 601 Rietz - Hoffman - General Electric Promo ISRM 13.00.00.51	UTO 601 Rietz - Hoffman - General Electric Promo Made in Denmark, Distributed by Hoffman, USA Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Slide: [ S, S&T, T ] Back Adv: General Electric Power Tubes (GE).
UTO 601 Rietz - Hoffman - Valerian Promo ISRM 21.08.07.41	UTO 601 Rietz - Hoffman - Valerian Promo Made in Denmark, Distributed by Hoffman, USA Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Slide: [ S, S&T, T ] Back Adv: Valerian - Palo Alto Tube Division Gift Of William Lisowski of Pennsylvania
UTO 602 Basic - Hoffman ISRM 20.04.01.142	UTO 602 Basic - Hoffman Made in Denmark, Distributed by Hoffman, USA Front Scale: K, A [ B, CI, C ] D, L Back Scale: Blank Back: Blank Gift of Philip Stanley, Worcster, Massachusetts
UTO 604 - Piece 1 of 2 of a set ISRM 22.03.01.98	UTO 604 Made in Denmark Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Slide: [ S, S&T, T ] Note: Presumed to be a sales kit for marketing purposes. Gift of Philip Stanley, Worcster, Massachusetts
UTO 605 - Piece 2 of 2 of a set ISRM 22.03.01.99	UTO 605 Made in Denmark Front Scale: 5inch // K, A [ B, CI, C ] D, L Back Scale: Blank Note: Presumed to be a sales kit for marketing purposes. Gift of Philip Stanley, Worcster, Massachusetts
UTO 631U Hoffman Log Log Duplex ISRM 20.04.01.214	UTO 631U Hoffman Log Log Duplex Made in Denmark Front Scale: L, K, A [ B, T Cot, ST, S Cos ] D, DI, P, S Back Scale: LL01, LL02, LL03, DF(CR) [ CF(T), CIF, CI(%), C(T) ] D(R), LL3, LL2, LL1 Gift of Philip E. Stanley collection, Worcster, Massachusetts
UTO 651U Hoffman Duplolog ISRM 20.04.01.173	UTO 651U Hoffman Duplolog Made in Denmark Front Scale: 5inch // L, K, A [ B, CI, C ] D, P, SCos, T Cot Back Scale: [ LL01, LL02, LL03 ] Gift of Philip E. Stanley, Worcster, Massachusetts
UTO 651U Darmstadt ISRM 20.04.01.217	UTO 651U Darmstadt Made in Denmark Front Scale: 5inch // L, K, A [ B, CI, C ] D, P, SCos, T Cot Back Scale: [ LL01, LL02, LL03 ] Back Advertisement: Thomas Mercer Ltd, St. Albans, England Gift of Philip E. Stanley collection, Worcster, Massachusetts
UTO 651U Darmstadt Hellerman ISRM 17.05.02.24	UTO 651U Darmstadt Hellerman Made in Denmark Front Scale: 5inch // L, K, A [ B, CI, C ] D, P, SCos, T Cot Back Scale: [ LL01, LL02, LL03 ] Gift of Mike Weaver, Bridgend, United Kingdom
UTO 661 Commerce ISRM 20.04.01.291	UTO 661 Commerce Made in Denmark Front Scale: 13cm // K, CR(DF) [ T(CF), %(CI), T(C)] R(D), A Back Scale: [ S, S&T, T ] Cursor: three hairlines Back: Blank Gift of Philip E. Stanley collection, Worcster, Massachusetts
UTO 930U Poly-e S541	UTO 930U Poly-e Made in Denmark Front Scale: L, K, A [ B, T Cot, ST, S Cos ] D, DI, P Back Scale: LL01, LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, Ll2, LL1 Original Owner: Robert Millar/Canada
UTO 930 Studium - Charvoz REF	UTO 930 Studium Made in Denmark Front Scale: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 Back Scale: ST, T, T₂ DF [ CF, CIF, CI, C ] D, DI, P, S Archive - Rod Lovett collection
UTO 930 Studium ISRM 09.01.12.110	UTO 930 Studium Made in Denmark Front Scale: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 Back Scale: ST, T, T₂ DF [ CF, CIF, CI, C ] D, DI, P, S Cursor: 3 Hairlines Note: Very poor red ink, be careful in cleaning this model Donated by David Hecht, Alexandria, VA
UTO Nr3-931U Poly-e Studium ISRM 09.01.12.124	UTO Nr3-931U Poly-e Studium Made in Denmark Front Scale: LL01, LL02, LL03, A [ B, L, K, C ] D, LL3, LL2, LL1 Back Scale: ST, T, T₂ DF [ CF, CIF, CI, C ] D, DI, P, S Cursor: 3 Hairlines Note: Very poor red ink, be careful in cleaning this model Donated by David Hecht, Alexandria, VA
UTO 932 - Charvoz REF	UTO 932 - Charvoz Made in Denmark for Charvoz Front Scale: LL00, K, A [ B, T Cot, ST, S Cos, C ] D, DI, LL0 Back Scale: LL01, LL02, LL03, DF [ CF, CIF, L, CI, C ] D LL3, Ll2, LL1 Archive - Rod Lovett collection
UTO F2145 ISRM 09.01.12.123	UTO F2145 Made in Denmark Front Scale: 11cm 4in // K, A [ B, CI, C ] D, L Back Scale: [ S, S&T, T ] Cursor: 3 Hairlines Original Owner: C.W. Wright, Paris, Kentucky, USA Note: Very poor red ink, be careful in cleaning this model Donated by David Hecht, Alexandria, VA

J.H. Weil & Co.

J.H. Weil & Co. Polylog 1140 Duplex
REF

J.H. Weil & Co. Polylog 1140 Duplex
Made in Denmark
Front Scale: LL01, LL02, LL03, DF [ CF, CIF, CI, C ] D, LL3, LL2, LL1
Back Scale: L, K, A [ B, T Cot, ST, S Cos ] D, DI, P
Archive - Steve Seale Collection

X-Act, Denmark.

X-Act No.222P 11cm/inch ISRM 22.03.01.101	X-Act No.222P 11cm/4-in Made by Denmark - Similar to UTO models, but cursor not interchangeable. Front Scale: 1/2-inch, 0-11cm, 0-4in // K, A[ B, CI, C ] D, L Back Scale: [ S, ST, T ] Back: Equivalents table. Gift Of Philip E. Stanley of Worcester, Mass.
X-Act No.222P 5.5-in (Rebranded for ALVIN) ISRM 22.03.01.102 Replace 09.01.12.05	X-Act No.222P 5.5-in (Rebranded for ALVIN) Made by Denmark - Similar to UTO models, but cursor not interchangeable. Front Scale: 5.5in // K, A[ B, CI, C ] D, L Back Scale: [ S, ST, T ] Back: Equivalents table. Gift Of Philip E. Stanley of Worcester, Mass.

Nordic Slide Rulesfrom Denmark and Sweden