USD $10
Set of Assorted Drafting Scales, Wood w/Ivorite. Some discoloration and damage to rules.
Stock: 1
USD $79
An extremely powerful pocket rule made by French manufacturer Graphoplex. In excellent condition, featuring a metric ruler on the upper edge, and red and blue engraved and marked scales.
(14 scales, 3 cursor lines, metric ruler)
Front –L, cos, B3, B2 [b2, a, b] B, LL3, LL2, LL1
Back – Blank [S&T, S, T, b]
Stock: 1
USD $5
K&E Ionic 56-3530 Drafting Ruler w/Case
Stock: 1
USD $15
K&E USCE Rulers, Imperial/Metric w/Slip Case, Set of 2
Stock: 1
USD $52
A nautical navigation aid for ship pilots (the water kind, not the space kind), using current speed, water speed, and related navigational data to aid a pilot in correcting course while navigating. Includes original box and instruction manual.
Stock: 1
USD $185
12.5″/10″ Special Purpose Full Size Slide Rule
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has black engraved and filled scales, with color coded pipe schedules for easy operation.
The reverse side of the rule features detailed usage instructions. Rule is in good condition, case is in poor condition.
Stock: 1
USD $245
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has red, blue and black engraved and filled scales.
Pipe schedules are color coded for easy operation. The unusual design uses many dedicated scales sets on both sides, and includes the fitted factory box and manual, and gold embossed leather case, all in MINT condition!
It’s a rule you will really enjoy in your collection, or on the job doing steam or hydraulic pipe fitting.
Stock: 1
USD $65
This is an unusual 6-scale (A, B, C, D – second B, C scales on reverse of slide) wooden rule from 1917, marked for reading out mils and yards – most likely this is either a survey rule, or was used for artillery calculations. The “FA” is very likely is an abbreviation for “Field Artillery.”
As rules go, given its age and production year, this rule is an actual piece of history.
Stock: 1
USD $75
This is an extremely advanced plastic body rule, from a lesser known Japanese manufacturer. It features a green contrast slide for easier reading, as well as black and red marked scales. Both sides of the rule feature padded feet, making the rule suitable for desktop use.
Comes in its original box, and two-part cardboard case.
(24 scales)
Front – LL-1, LL-2, LL-3, DF, [CF, CIF, CI, C], D, LL3, LL2, LL1
Back – L, K, A, [B, ST, T1, S, C], D, DI, LL0, LL-0
Stock: 1
USD $165
12.5″/10″ Special Purpose Full Size Slide Rule
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has black engraved and filled scales, with color coded pipe schedules for easy operation.
The reverse side of the rule features detailed usage instructions. This example is in fair condition, with wear on the case and rule.
Stock: 1
USD $225
12.5″/10″ Special Purpose Full Size Slide Rule
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has black engraved and filled scales, with color coded pipe schedules for easy operation.
The reverse side of the rule features detailed usage instructions.
Stock: 1
USD $40
Novotni Weight Slide Rule, used for calculating mass based on metal type and volume. General discoloration to body, significant wear around edges. In working condition, and includes original manual.
Stock: 1
USD $25
Pediatric Dial-A-Dose Circular Slide Rule w/Instructions
Stock: 1
USD $49
This is a specialist rule for calculating resistance attenuation in 600 ohm circuits, using impedance, voltage, and resistance. Includes the original case and instruction manual.
Stock: 1
USD $125
This is a beautiful, metal body, simplex, circular rule in excellent condition. We are unfortunately unable to give a great deal more depth on the rule due to most of the documentation we have on it being in German, but both the case and rule are in excellent condition.
Stock: 1
USD $95
5.5″ Circular Aviation Slide Rule
Constructed with one rotating film disk, and rotating cursor on each side. This flight computer handles altitude, pressure, wind drift, time, temperature, and fuel problems.
The rule gives calculations primarily in US/Imperial units, with some calculations available in metric.
Stock: 1
USD $75
This is a larger, 6″ circular flight computer, featuring a variety of functions on the front side for calculating air speed, fuel consumption, distance, and altitude/temperature adjustments. The reverse side features a cross-wind calculator.
Includes the original case and operating manual.
Stock: 1
USD $65
This is a larger, 6″ circular flight computer, featuring a variety of functions on the front side for calculating air speed, fuel consumption, distance, and altitude/temperature adjustments. The reverse side features a cross-wind calculator.
Includes the original case, which has a torn edge.
Stock: 1
USD $125
This flight computer features a variety of functions on the front side for calculating air speed, fuel consumption, distance, and altitude/temperature adjustments. The reverse side features a cross-wind calculator.
This rule is a smaller version of the CR-3, and includes the original case.
Stock: 1
USD $125
This duplex circular rule looks to have 15 scales, and includes its original manual and case.
Stock: 1
USD $75
This is an unusual rule created by Tektronix for circuit computations, accounting for frequency, resistance, capacitance, and inductance. The front of the rule features the various calculation scales, and the back of the rule features reference formulas.
Stock: 1
USD $55
This is a desktop / countertop conversion tool that uses three dials to convert mass and volume, and a scale for temperature. Originally meant for use in the kitchen, but just as good for other purposes.
Stock: 1
USD $65
Novotni Weight Slide Rule, comes in original box and includes original manual.
Stock: 1
USD $27
An inexpensive and versatile plastic body pocket rule featuring metric/imperial rulers, and 9 scales (via reversible slide), includes a blue vinyl case.
(9 Scales, metric/imperial rulers)
Front – A, [ B, CI, C], D, K
Reverse – Blank [ S, L, T ]
Stock: Lots
USD $21
An inexpensive and versatile pocket rule featuring metric/imperial rulers, and 9 scales (via reversible slide). Plastic body, bulk discounts available – contact for details.
(9 Scales, metric/imperial rulers)
Front – A, [ B, CI, C], D, K
Reverse – Blank [ S, L, T ]
Stock: lots
USD $49
What’s it do? Not entirely sure, but it is in very good condition with no marking or fading. Features plastic standoff feet for desk operation.
Stock: 1
USD $49
A simple and durable pocket rule for beginners, featuring 7 scales, and an all plastic body. Rule is in good condition, includes the original case, which is in poor condition.
(7 Scales)
Front – K, A, [B, CI, C], D, L
Back – Blank
Stock: 1
USD $59
An unusual pocket rule from Eastern Europe, this rule’s scale markings do not use standard notation, and instead just mark out the actual functions (similar to Koh-I-Noor rules). Includes leather slip case.
(13 Scales, 1 ruler)
Front – √(1-x2), x3, xzz, [e^0.01x, e^0.1x, e^x], x, sin, tg
Back – Blank [x, log x, 1/x, x2]
Stock: 1
USD $7
Who says good things can’t come in small packages? This extremely budget friendly rule is a credit to engineering, featuring a wrap-around cursor that allows you to use the three scales on the reverse side, and a decimal conversion chart on the reverse of the slide. Made from just three pieces of plastic, this is a good addition to any collection.
(8 Scales)
Front – A, [ B, CI, C, ] D
Back – S, L, T (decimal equivalents on the back of the slide)
Stock: 2
USD $75
The Acumath 500 is a budget friendly, but still fairly capable rule, designed for students and those learning to use a slide rule. White plastic body with metal end braces, and the original plastic carry case.
(9 Scales)
Front – S, K, A, [B, CI, C] D, L, T
Back – Conversion factors
Stock: 1
USD $169
This is a Mark 5 Pilot Balloon Slide Rule manufactured around 1968. It measures 63cm[24.75in] long, 6.3cm[2.5in] wide and 12mm[0.5in] thick. The printed scales are engraved in the plastic faces. The slide rule has 4 captive cursors that ride in slots on the top and bottom edges. Each can be moved independently of one another. Steel knobs at both ends of the slide facilitate movement of the slide. These were made for and used by UK Government agencies, and not individuals. The Met.(meteorological) Office of the United Kingdom designated at least 6 different Pilot Balloon slide rule models. The first model in appearing 1915 made of wood by J.J. Hicks with two slides and introduction of the final, MK 5 model in the Late 1960’s.
Made in England by Blundell Harling Ltd – Weymouth, England.
Stock: 1
USD $24
12″ / 10″ plastic body Slide Rule
LATE MODEL, made by Sterling (later Borden which bought out both Acumath and Sterling Plastics, and continued to sell under those names). Includes instructions, black engraved and filled scales, and yellow contrasting color slide. Can do 16 metric conversions from US standards to Metric units and vice versa. Front slide for distance and area, reversible slide for weight and volume conversions. An inexpensive and practical rule for any science students, cooks, or anyone needing to work in both unit systems. Made in USA. These rules come new, still sealed in their original packaging.
(16 Conversions)
Front – [ Inches/cm, m/feet, m/yards, miles/km, sq. in./sq. cm, sq.m/sq. ft x10, sq. m/sq yards, sq. miles/sq. km ]
Back – [ cu. in./cu cm x10, cu m/cu.ft.x10, cu. m/cu. yards, l/qt., oz./g x10, kg/lbs, metric tons/short tons, gal./l]
Stock: 3
USD $59
This is a rudimentary, all plastic, pocket rule. While it is more on the budget end, it does still feature a wide variety of scales, capable of doing most routine math and calculations, and comes with a convenient fraction-to-decimal conversion scale. Includes its original slip case.
(15 Scales)
Front – K, A, [B, S, T, C], D, DI
Back – Fraction Conversions, [L, C2, C1], D1, D2, D
Stock: 1
USD $135
This is a NIB Ricoh 116, featuring a transparent plastic case and original manual. Factory box is missing a flap and has signs of wear. This is an excellent student rule or engineering rule that features a metric ruler along the upper edge and a variety of formula and technical references on the reverse.
(24 Scales)
Front: K, DF, CF, CIF, CI, C, D, A, DI [T1, T2, L, S]
Back: Metric and imperial conversions, reference formulae, scale references, metal weights
Stock: 1
USD $225
This has scales 423 and 414
A wonderful set with original factory box (serial number 25356), made in England. This is the unique cylindrical rule with telescoping scales, complete with the original black storage box. Everything is in very good condition. This rule has the equivalent of a 66 inch scale, with resulting incredible resolution!
Scale 423
Scale 414
For multiplication, division, proportion, percentages, foreign exchange.
Stock: 1
USD $55
An inexpensive, beginner, pocket rule. All plastic construction, single-sided. Includes manual.
(7 Scales)
Front – K, A, B, C1, C, D, L
Back – Blank
Stock: 1
USD $35
Originally designed as Geocaching coins by Dutch Geocacher Technetium, these Pale Horse Designs coins are a unique slide rule item. The core is die cast zinc alloy to achieve the high detail, with either gold or silver toned plating, or nickel plating, depending on the design. The inner triangle design is Sierpiski’s fractal triangle. Each coin comes inside a clear plastic display carrier, and a padded cardboard display box with cutout for viewing the coin.
The Sunlight Coin is satin gold and silver finish with a jade accent, and is both a wonderful aesthetic addition to any collection, as well as having a unique feel, with a working slide rule on the face (the two outer scales are C and D, the innermost is a Log Log scale, and smith chart on the reverse). These 50mm diameter coins are heavy and thick (5mm), not a flimsy plastic item, but a solid metal good luck piece or pocket fancy you will enjoy for a long time.
The Midnight and Sunlight coins can be purchased as a set for $65, while quantities last.
We will not be doing any further production runs of these coins.
Stock: 15
USD $35
Originally designed as Geocaching coins by Dutch Geocacher Technetium, these Pale Horse Designs coins are a unique slide rule item. The core is die cast zinc alloy to achieve the high detail, with either gold or silver toned plating, or nickel plating, depending on the design. The inner triangle design is Sierpiski’s fractal triangle. Each coin comes inside a clear plastic display carrier, and a padded cardboard display box with cutout for viewing the coin.
The Midnight Coin is blue and nickel plated, and is both a wonderful aesthetic addition to any collection, as well as having a unique feel, with a working slide rule on the face (the two outer scales are C and D, the innermost is a Log Log scale, and smith chart on the reverse). These 50mm diameter coins are heavy and thick (5mm), not a flimsy plastic item, but a solid metal good luck piece or pocket fancy you will enjoy for a long time.
The Midnight and Sunlight coins can be purchased as a set for $65, while quantities last.
We will not be doing any further production runs of these coins.
Stock: 2
USD $65
Micronita 505 Pocket Rule
(9 scales, 1 metric ruler)
Front – A, B, CI, C, D, K [S, L, T]
Back Blank
Stock: 1
USD $159
M.H. Mear Gas Flow Calculator Circular Rule (new/mint)
Stock: 1
USD $59
Coast Navigation Simex Course Converter (new/mint)
Stock: 1
USD $119
Stephenson-Pfahl Hardenability Slide Rule
Stock: 1
USD $85
Fearns W25 Castings and Forging Weight Calculator Circular Rule (new/mint). One with a green case and one with a brown case.
Stock: 2
USD $85
Fearns-Mear Machining Time Calculator Circular Rule (new/mint)
Stock: 2
USD $159
M.H. Mears Pipe Flow Calculator for Liquids & Gases (new/mint)
Stock: 1
USD $135
Concise No. 380 Radio Converter Circular Rule (new/mint), includes case and instruction manual.
Stock: 2
USD $85
Earns W28 Steelwork Weight Calculator Circular Slide Rule
Stock: 1
USD $59
Do you need to measure fallout radiation from a nuclear detonation? This is what you need to do that! I’m sure there are other ways, but this way will absolutely not fail you (doesn’t need batteries), so long as you are sufficiently far away to safely be able to operate the rule.
Stock: 3
USD $125
4 1/2″ Binary Pocket Circular Rule (in green)
(21 Scales !)
Front: – C, CI, A, K, L, Log Log (1.0015-1,000,000), fractions, fractions, drill/thread, mm
Back: degrees, sines, tans, degrees, sines, tans, degrees, sines, tans, Fractional Conversions
Stock: 1
USD $65
Jakar 88 College Duplex Full Size Rule (includes support ruler), designed for students, engineers, architects and draughtsmen.
(22 Scales)
Front – LL1, LL2, LL3, DF, CF, CIF, CI, C, D, L, K
Back – T1, T2, A, B, BI, CI, C, D, P, S, ST
Stock: 1
USD $50
Jakar 66 Electro Slide Full Size Simplex Rule (metric ruler on top edge), designed for students, engineers, architects and draughtsmen.
(13 Scales)
Front – K, E, A, B, CI, CI, D, LL3, LL2, L [S, ST, T]
Back – Blank
Stock: 1
USD $65
Graphoplex 694a Full Size Rule w/case and manual (in French)
(20 Scales)
Front –L, LL3, DF, CF, CIF, CI, C, D, LL2, LL1
Back – P, T>45, A, B, SRT, S, C, D, DI, K
Stock: 1
USD $165
nPK-69 Russian Dual Circular Slide Rule w/Chart – RARE.
Stock: 1
USD $40
Aerospace Shock-Proof Caliper 12″, Stainless Steel
Stock: 1
USD $29
An economical and practical student rule for the beginner slide rule enthusiast! Plastic body, with contrast color slide for easier reading. Comes with a leatherette case.
Scales include:
Front – L, K, A, B, CI, C, D, ST, T, S
Back – Blank
Stock: 2
USD $25
A clear and easy to read student rule, with yellow (taupe?) contrast bands on the rule for easier reading. Includes a leatherette case.
Scales include:
Front – A, DF, CF, CIF, CI, C, D, K
Back – Blank
Stock: 2
USD $29
An economical and practical student rule for the beginner slide rule enthusiast! Plastic body, with contrast color slide for easier reading.
Scales include:
Front – L, A, DF, CF, CI, C, D, ST, T, S
Back – Blank
Stock: 1
USD $115
Easy to read with black and red scales, this is a good beginner rule that includes a metric ruler on the upper edge.
Scales include:
Front – K, A, B, CI, C, D, L, S, ST, T
Back – Blank
Stock: 1
USD $75
An advanced 24 scale rule that comes in a presentation case, rule features feet on the reverse side for easier desktop use.
Scales include:
Front – ST, T, T2, DF, CF, CIF, CI, C, D, DI, P, S
Back – LL01, LL02, LL03, A, B, L, K, C, D, LL3, LL2, LL1
Stock: 1
USD $225
This special late production Foxboro flow rule is used to calculate flow parameters and rates for liquids, steam or gas. This is the version custom made for Foxboro by Hemmi of Japan, and has red, blue and black engraved and filled scales.
Pipe schedules are color coded for easy operation. The unusual design uses many dedicated scales sets on both sides, and includes the fitted factory box and manual, and gold embossed leather case, all in MINT condition!. It’s a rule you will really enjoy in your collection, or on the job doing steam or hydraulic pipe fitting.
Stock: 2
USD $69
This beginner bamboo rule features a metric ruler on the upper edge of the rule, and an imperial rule on the lower edge.
Front – K, A, B, CI, C, D, L, S, ST, T
Back – Reference data and usage instructions
Stock: 1
USD $35
This antique wooden rule features an imperial ruler along the top edge, and basic scales on the front. Based on its age, scales, and reference tables, this looks like an early architect’s rule for construction projects.
Scales include:
Front – A, B, CI, C, D, K
Back – Reference chart for various building materials
Stock: 1
USD $35
Made in Japan, this bamboo duplex pocket rule has 13 scales.
Scales include:
Front – C, D, L, CF, DF, CI
Back – A, B, C, D, K, S, T
Stock: 1
USD $45
A basic plastic body simple pocket rule with rulers on the upper and lower edges of the rule. Comes in original factory case and box.
Scales include:
Front – A, B, C, D,K, CI
Back – Blank
Stock: 2
USD $15
This is a very basic rule made from a wood body and laminated plastic for the scales. It looks like it was used for instructional or educational purposes, and was produced in bulk. The scales are starting to delaminate, making some of the numbers harder to read. Definitely an unusual piece of history.
Scales include:
Front – A, B, C, D,K, CI
Back – Blank
Stock: 1
USD $129
An outstanding and attractive rule from Hope Slide Rule Manufacturing Co. in Japan, these rules are inmint condition, complete with plastic white/green 2-part case and an English factory manual.
Perfect sets of a very advanced Log Log rule with blue accent stripes on primary scales, RED inverse scale markings, plus self-documenting on the right hand side. Has 4 trig scales (T1, T2, ST and S), PLUS P pythagorean scale, an exceptionally rich scale set and excellent user features.
White plastic body and end braces with engraved and filled scales in red/black. Folded scales are at 3, with Pi also marked. Front ABCD scales also have over-range at both ends.
Front – LL01, LL02, LL03, A, [ B, L, K, C, ] D, LL3, LL2, LL1
Back – T2, T1, ST, DF, [ CF, CIF, CI, C, ] D, P, S
Stock: LOTS!
USD $165
This all plastic rule features 25 scales, and has rubberized feet to keep the rule fixed in place for desktop use. This rule includes the rule, original case, and conversion/formula table.
Scales are as follows:
Front – LL01, LL02, LL03, DF, CF, CIF, K, CI, C, D, LL3, LL2, LL1
Back – LL00, L, T>45, A, B, T<45, SRT, S, C, D, P, DI, LL0
Stock: 1
Sphere Research Corporation