USD $320
Class C: Good condition. Some visible scale bleeding on one or both sides. The (very rare) display case is discolored, has a scratch on one end, and a crack on the other.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 1
USD $165
Class D(ish): What happens when you have a rule of this type that’s missing a box and some other items, that’s not quite a Class D, but isn’t quite a Class E? The result? The Dish Class. Reasonable condition. Visible/pronounced scale bleeding on both sides, the case on this rule isn’t as nice as a full Class D, but it’s also on sale…
Faber Castell’s advanced duplex log log rule, widely used in Europe but seldom seen in North America, This rule has a plastic body with adjustable gold anodized aluminum end braces, black and red filled and engraved scales, plus green accent stripes. This is a powerful design with the Rietz overrange scale extensions, Pythagorean scale (P) 6 log log scales and w and W’ expanded square root scales. Scales are sall self-documenting on the right hand side, and the rule has a 5/6 line cursor.
Scales include:
Front – T1, T2, K, DF, [ CF, CIF, CI, C, ] D, S, ST, P
Back – LL03, LL02, LL01, W2 [ W2′, L, C, W1′, ] W1, LL1, LL2, LL3
Stock: 1
USD $275
Class D (reduced from USD$325): Reasonable condition. Visible/pronounced scale bleeding on both sides, case may have considerable dark spots and/or discoloration.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges.
This specific rule comes in a rare FC slide box, as opposed to the standard leather case.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 1
USD $45
This may be a more basic rule for students, but it still has a variety of very useful features. It has a metric ruler on the upper edge of the rule, high contrast green scale accents, and black and red scales.
Scales include:
Front – K, A, B, L, CI, C, D, S, ST, T1, T2
Back – blank
Stock: 3
USD $75
An excellent rule for promising engineers, this 22 scale rule comes with a formula reference card and rules, as well as a manual. Unfortunately they are in German, but math is the universal language, right?
Scales include:
Front – L, K, A, B, BI, CI, C, D, LL1, LL2, LL3
Back – T1, T2, DF, CF, CIF, S, C, D, S, ST, P
Stock: 1
USD $425
Class A (reduced from USD$495): Excellent/mint condition. Green cases may have some small dark spots/discoloration, brown cases have no discoloration. May have some minor scale bleeding on the reverse side of the rule (non-color side).
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 2
USD $425
Class A (reduced from USD$495): Excellent/mint condition. Green cases may have some small dark spots/discoloration, brown cases have no discoloration. May have some minor scale bleeding on the reverse side of the rule (non-color side).
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 1
USD $375
Class B (reduced from USD$425): Very good condition. Green cases may have some dark spots/discoloration. Some scale bleeding on reverse side (not the full color side) of the rule.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 9
USD $375
Class B (reduced from USD$425): Very good condition. Green cases may have some dark spots/discoloration. Some scale bleeding on reverse side (not the full color side) of the rule.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 4
USD $325
Class C (reduced from USD$375): Good condition. Some visible scale bleeding on one or both sides. Some dark spots or discoloration on case.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 8
USD $325
Class C (reduced from USD$375): Good condition. Some visible scale bleeding on one or both sides. Some dark spots or discoloration on case.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 2
USD $275
Class D (reduced from USD$325): Reasonable condition. Visible/pronounced scale bleeding on both sides, case may have considerable dark spots and/or discoloration.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 12
USD $275
Class D (reduced from USD$325): Reasonable condition. Visible/pronounced scale bleeding on both sides, case may have considerable dark spots and/or discoloration.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 3
USD $125
Class E: Poor condition. Extensive scale bleeding and discoloration on one or both sides. Case may have considerable dark spots and discoloration.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 1
USD $125
Class E: Poor condition. Extensive scale bleeding and discoloration on one or both sides. Case may have considerable dark spots and discoloration.
Considered to be the most advanced slide rule produced: gold anodized adjustable aluminum end braces, duplex 5/4-line cursor, two color (red/black) scale markings, and trademark mint green stripe on primary scales (both sides), plus additional blue stripes on the A and B scales, and massive 2 1/4″ wide body. Expanded W square root scales, for both the square root of x and 10x, 8 log log scales, and raised rubber bumpers to prevent cursor scraping, and to give the rule grip on a desktop. Body is fully alignable at the aluminum end-pieces, and provides finger grip areas on the slide for better movement. Cursor pops off (note the recess on the side bars) for easy cleaning, while retaining its alignment, a very handy feature! Rule is self documenting on right hand side for all scales. Has Pythagorean scale (P), expanded square scales, folded scales and scale over-ranges. Includes: Original box, case, original manual in Spanish, reprint manual in English, and accessory rule.
Scales include:
Front – T1, T2, K, A, DF, [ CF, B, CIF, CI, C, ] D, DI, S, ST, P
Back – LL03, LL02, LL01, LL00, W2 [ W2′, CI, L, C, W1′, ] W1, LL0, LL1, LL2, LL3
Stock: 2
USD $179
It is rare to find these rules, much less find them in working condition. This rule features 10 scales, an imperial ruler on the upper edge, and mechanical adding machine on the back. Comes with original case and stylus.
Scales include:
Front – L, K, A, B, CI, C, D, S, ST, T
Back – Addiator, unit conversion, and common formulae
Stock: 1
USD $195
Long before Samsung was trying to sneak a stylus into their smartphones, Faber Castell was already concealing them in their slide rules. This is a very rare surviving example of one of those rules, that features a small stylus that is concealed in the upper left corner of the rule, and can be slid out to operate the addiator integrated into the back of the rule. Rule features an imperial ruler on the upper edge, and a metric ruler on the lower edge.
Scales include:
Front – 7 scales (+ Cos, ST, T scales on the reverse side of the slide)
Back – Addiator and unit conversion instructions.
Stock: 1
USD $75
This rare Faber Castell wood rule features 7 scales on the rule proper, and metric/imperial rulers on the upper and lower edges fo the rule.
Scales are as follows:
Front – 7 Scales
Back – Reference and conversion references (in German)
Stock: 1
USD $59
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
USD $165
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
USD $30
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
USD $35
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
USD $325
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
USD $90
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: 1
Sphere Research Corporation