Sphere
Research
Corporation
Sphere
Research
Corporation
We are currently adding to the updated slide rule repository as we verify our inventory, please do not hesitate to consult the old site - however, please note that the old site has not been regularly updated since 2022.
We will be periodically be putting overstock slide rules on sale, so be sure to keep an eye on the sale seciton of this page (changes monthly).
As visible on the front of the rule, this wood K&E pocket rule dates back to 1900, and it is rare to find a rule of this vintage in this good a condition. This is a single sided rule, with an integrated 5" ruler on the top edge.
Scales are as follows:
Front - A, B, C, D
Back - Common unit conversion table
Stock: 1
This rule is specifically designed for business math and currency calcualtions. It features an imperial ruler along the top edge of the rule, and separate markings for handling currencies. On the reverse side of the rule is a mechanical addiator, operated using the included stylus, and formulas/directions for completing conversions, interest payments, and pensions.
Scales are as follows:
Front - DF, CF, CI, C, D, L, SH/D, $, LL1, LL2
Back - Operating instructions, formulas, addiator
Stock: 1
This oversize rule measures approx 56.5cm, and features an imperial ruler long the upper edge of the rule, and a metric ruler along the lower square edge of the rule.
Scales are as follows:
Front - A, B, CI, C, D, S, ST, T
Back - Operating instructions, formulas, conversion tables
Stock: 2
This oversize rule measures approx 56.5cm, and features a metric ruler long the upper edge of the rule. The lower edge of the rule features the S&T scales, readable using the wraparound cursor on the body of the rule.
Scales are as follows:
Front - A, B, CI, C, D, S, T. LL1. LL2, LL3
Back - Operating instructions (in german), formulas, conversion tables
Stock: 1
This 13-scale full size rule features large, color contrasted scale for easy reading, and operating instructions printed on the reverse side of the rule. Includes the original case, box, and operating instructions (in German).
Scales are as follows:
Front - A, DF, CF, CIF, CI, C, D, kW, k
Back - Z', N', Z, N, instructions
Stock: 1
This 13-scale full size rule features large, color contrasted scale for easy reading, and operating instructions printed on the reverse side of the rule. Includes the original case and operating instructions (in German).
Scales are as follows:
Front - A, DF, CF, CIF, CI, C, D, kW, k
Back - Z', N', Z, N, instructions
Stock: 1
This rare 13-scale pocket rule features a metric ruler along the top edge, and an imperial ruler on the reverse side of the rule. This is an all plastic rule, and comes with the original instruction sheet in German.
Scales are as follows:
Front - Metric ruler, L, K, A, B, CI, C, D, F, S, T, LL1, LL2, LL3
Back - Imperial ruler
Stock: 1
This rare Faber Castell wood rule features 8 scales on the rule proper, a metric ruler on the upper edge of the rule, and another logarithmic reference on the lower edge of the rule where you would normally find an imperial ruler. There is some separation beginning between the plastic and wood body on the top left of the rule.
Scales are as follows:
Front - 7 Scales
Back - Reference and conversion references (in German)
Stock: 1
This all-metal 23-scale rule has some unique features. The reverse side of the rule features a split scale, with instructions outlined in the centre of the rule, and positive values read on the left end of the scale, and negative values on the right.
Scales are as follows:
Front - ^-3, ^-3, ^-3, L, T, T, ST< S, CI, C, D, ^-2, ^-2
Back - C, D, T', T', ST', S', DN, RN-DZ, ^-2, ^-3
Stock: Lots!
NEW boxed sets complete with Case, Manual, and Warranty Certificate, all have extensive directions on the reverse of the rule!
ES (Eye-Saver) Yellow aluminum construction, T (traditional) white construction. Very high quality, American Made, Pickett rule. An excellent student rule with good trig capability. Boxes have carton creases, storage scuffs, tears and marks, we will ship the best first. These are transitional sets, the rule is marked N902ES (late production), but the box still says 902ES.(9 Scales)
Front - K, A, [ B, T, S, CI, C, ] D, L
Back - instructions, fractional/decimal equivalents
Stock: Lots!
A beginner plastic simplex rule, this Pickett pocket rule is great for beginners or for casual adventurers worried about losing their higher end pocket rules while spelunking. Don't leave the Bat Cave without this!
Scales include:
Front - A, B, C, D, L, K, CI
Back - Blank
Stock: 1
This rule is new and still in it sfactory sealed bag, the case is also in excellent condition with no staining or wear. As features, this rule has 15 scales, a metric ruler along the upper edge of the rule, and formulas and data conversion tables on the back.
Scales include:
Front - T, K, A, B, BI, CI, C, D, P, S, L, LL0, LL1, LL2, LL3
Back - Formulas and data tables
Stock: 1
Don't let the box fool you, this rule is in excellent shape and is still in its sealed factory plastic. It features 24 scales, and is a rule for advanced users.
Scales include:
Front - L, F, K, A, B, K', CI, C, D, LL3, LL2, LL1
Back - CL, SL, M, TL, R, ST, T, S, C, D, DI, SIN/COS
Stock: 1
Marketed under GeoTec/hughes-Owens, this bamboo pocket rule is still marked on the rule as a Sun/Hemmi rule. It features 23 scales, and includes the original box, manual, and case.
Scales include:
Front - LL/1, LL/2, LL/3, T, ST, S, C, D, LL3, LL2, LL1
Back - LL0, LL/0, K, DF, CF, CIF, CI, C, D, R1, R2, L
Stock: 1
This seven scale pocket rule features an unusual cursor design, with a bulkier metal frame on only three sides of the cursor. Imperial/metric ruler on the upper and lower edges of the rule. As is true of most Hemmi rules, this is a bamboo rule.
Scales include:
Front - A, B, C, D, S, L, T
Back - Blank
Stock: 1
This small Hemmi pocket rule is similar to the K&E 4031, and is slightly larger than a Hemmi 30. Features a magnifying cursor, and metric/imperial rules on the upper and lower edges of the ruler.
Scales include:
Front - A, B, C, D, S, L, T
Back - Blank
Stock: 1
This bamboo rule is still in its original factory sealed plastic, however, the rule does show signs of discoloration and marking from having been stored for so long. The case is also fairly worn and has lost its finish in multiple areas. Ruler in inches along the upper edge of the rule.
Scales include the following:
Front - A, C, D, K, CF, DF, CI, L, TI1, TI2, SI1
Back - Blank
Stock: 1
Still in excellent condition, this Hemmi Versatrig rule was released as a Geotec branded rule, but still includes the original Sun Hemmi markings. Original leather pocket case with clip included.
Scales include the following:
Front - C, D, K, CF, DF, CI, R1, R2, CIF
Back - A, C, D, L, S, T, DI, ST
Stock: 1
This full size rule features 31 scales, original factory box, case, original manual, and support ruler with conversion tables. The rule itself features rubber standoff feet for use on a desktop. There is some rust damage to the retaining screw on the cursor.
Scales include:
Front - LL00, LL01, LL02, LL03, DF, CF, CIF, L, CI, C, D, LL3, LL2, LL1, LL0
Back - H2, Sh2, Th, K, A, B, T, ST, S, P, C, D, DI, Ch, Sh1, H1
Stock: 1
This single sided rule is suitable for the mathematician on the go and features clear plastic edging on the upper and lower ruler edges with imperial and metric rulers.
Scales include:
Front - X, XZ, X2, X3, X 2/Z, 1/X, SIN, TG, ROOT (1-X2), LGX, E^X, E^0.1X, E^0.01X
Back - Blank
Stock: 1
This oversize rule measures approx 58cm, and features a metric ruler along the upper edge of the rule. Along the lower, square, edge of the rule are the S&T scales for the rule, readable using the extended cursor that wraps around the edge of the rule.
Scales are as follows:
Front - K, A, B, CI, C, D, F, S, T, LL1, LL2, LL3
Back - Formulas, data conversion tables
Stock: 1
This full size rule features 13 scales, with color contrasted markings for easy reading. There is a mteric ruler along the top edge of the rule, and commonly used formulas and data conversion tables on the reverse side of the rule.
Scales are as follows:
Front - L, K, A, B, CI, C, D, P, S, T, LL1, LL2, LL3
Back - Formulas, data conversion tables
Stock: 1
This full size rule features 25 scales, and includes the original case and included formula/data rule (which includes common geometric formulas, and unit conversions).
Scales are as follows:
Front - Th, Sh2, Sh1, A, B, T<45, T<45, ST, S, D, DI, K
Back - LL01, LL02, LL03, DF, CF, CIF, L, CI, C, D, LL3, LL2, LL1
Stock: 1
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
An all-plastic rule, the Omega 797 features 22 scales and comes with the original factory box and manual. It also features rubber stand-off feet on both side of the rule for easy desktop operation.
Scales are as follows:
Front - T, ST, DF, CF, CIF, CI, C, D, P, S
Back - LL01, LL02, LL03, A, B, L, K, C, D, LL3, LL2, LL1
Stock: 1
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!
New and in mint condition, made in Czechoslovakia. A great beginner and student rule.
Basic Rietz format rule (has over-range scale extensions for easier operation) with added reference features. It has a black/red self-documenting scale arrangement and pale yellow slide. The slide reverse has trig (S, ST, T) scales, and the back has a treasure trove of useful data and factors. It has a slightly magnifying multi-line simplex cursor design that does area of a circle, plus some other interesting stuff like horsepower conversion. These are beautifully made rules, very well constructed. We will include basic instruction reprints, as these came bulk packed with with no manuals.
Stock: Lots!
Wood rule with all metal braces, and glass/metal cursor. includles the original leather case, and separate conversion table and formula reference card.
Scales include:
Front - C, D, L, CF, DF, CI, CIF,LL2, LL3, LL02, LL03
Back - A, B, D, K, S, T<, T>,DI, ST, LL1, LL01
Stock: 1
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
This Staedtler rule features metal cursor end caps, and metal braces with supporting ridges to allow for desktop use of the rule. Includes a new leather case engraved with the Sphere Research Logo.
Scales include:
Front - A, B, C, D, L, K, LL1, LL2, LL3, LL01, LL02, LL03
Back - C, D, P, S, T, CF, CI, DF, CS, CT, ST, CIF
Stock: 1
An absolute mathematical rapier of the pocke rule world, this Satedtler rule has enough scales for even the most significant problems. Includes original leather clip pocket case.
Scales include:
Front - C, D, CF, DF, CI, CIF, LL1, LL2, LL3, LL/1, LL/2, LL/3
Back - A, B, C, D, K, L, P, S, T, LL0, LL/0
Stock: 1
Still in good condition, this rule has no scale bleeding and moves smoothly. Features imperial and metric rulers on the upperand lower edges of the rule, back features standard unit conversions.
Scales include:
Front - A, B, C, D, K, CI, S, L, T
Back - Unit conversion chart
Stock: 1
Made under the joint marques fo KOH-I-NOOR and Graphoplex is this X2. Features a metric ruler along the top edge and original leather case in good condition.
Scales include:
Front - a, b, b^2, B, B^2, B^3, L, LL1, LL2, LL3, cos, S, T, S&T
Back - Blank
Stock: 1
This fairly rare rule from French manufacturer Grphoplex incorporates some physical features on the rule that are not seen on most others. On each side of the rule's end brackets are rubberized feet that keep the rule's body away from the surface it's on so that it can be used resting on a desk.
Being French, the manual and forumula reference card are both written in French.
Scales include:
Front - A, B, C, D, L, P, S, T, DI, ST, LL0, LL00
Back - C, D, K, CF, CI, DF, CIF, LL1, LL2, LL3, LL01, LL02, LL03
Stock: 1
From French manufacturer Graphoplex comes the Roplex circular rule. Included instructions are in French, as is the wordin gon the rule itself. Unlike other circular rules, this rule is entirely encased, with scale/slide movement and cursor movement effected via the two adjustment dials in the top corners.
Stock: 1
On one side, this handy calculator is useful for calculating wire sizes based on distance and current, and conversely for determining maximum distances based on cable size and current. The other side handles conversions for motor power output.
Stock: 1
This ruler uses temperature responsive liquid crystals to read-out room temperature in C/F. It also features metric and imperial measures on the upper and lower edges, and a slide in the center for completing metric/imperial conversions for mass, volume, and distance.
Stock: 1
If you're still refusing to use the metric system, and don't want to do your calculations using fractional lengths of football fields, then this circular slide chart will be very useful. On the inner ring it provides calcualtions in both fractional and decimal quantities.
Stock: 1
If you're still refusing to use the metric system, and don't want to do your calculations using fractional lengths of football fields, then this circular slide chart will be very useful. On the inner ring it provides calcualtions in both fractional and decimal quantities.
Stock: 1
Don't be caught in the cockpit without this device! Set comes complete with case, manual, multiple charts, and double sided circular slide rule.
Provides arithmetic and vector solutions for for aircraft speeds of 90 to 2 000 knots, with consideration of errors due to aircraft acceleration. Dead reckoning capability of a plotting board.
Stock: 1
This chart is configured for 30-40 degrees in the southern hemisphere. This chart not only helps identify which stars are visible at any hour and day, but also shows this information thousands of years into the past, the present, and well into the future.
Stock: 1
This star finder and identifier is more versatile than many others, as it comes with 10 different latitude overlays ensuring this star-finder is useable in many different areas.
Includes manual, 10 latitude overlays, double-sided circular map/chart, and protractor.
Stock: 1
Designed by H. Joseph Gerber, survivor of a Nazi concentraition camp, the Gerber Variable Scale is used to easily complete calculations on graphs and curves. It is used for graphical applications for which reading, plotting, and interpolating needs to be done.
Both the scale and leather case are in excellent condition.
Stock: 1
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