Gage Block Tolerances: B89.1.9 Gage Block Tolerances Inch System: Tolerances expressed in microinches (.000001") 1 millionth of an inch Order Webber Grade LM Order Webber Grade AA B89.1.9 Grade 00 Order Webber Grade A1 B89.1.9 Grade 0 Size Tolerance Variation in Length Tolerance Flatness Tolerance Size Tolerance Variation in Length Tolerance Flatness Tolerance Size Tolerance Variation in Length Tolerance Flatness Tolerance Thru .050" +1.2/-1.2 1.2 1.2 +4/-4 2 2 +6/-6 4 4 Thru .400" +1.2/-1.2 1.2 1.2 +3/-3 2 2 +5/-5 4 4 Thru 1" +1.2/-1.2 1.2 1.2 +3/-3 2 2 +6/-6 4 4 Thru 2" +2.0/-2.0 1.2 1.2 +4/-4 2 2 +8/-8 4 4 Thru 3" +3.0/-3.0 1.2 1.2 +5/-5 3 Rect.: 2, Sq.: 3 +10/-10 4 4 Thru 4" +4.0/-4.0 1.2 1.2 +6/-6 3 Rect.: 2, Sq.: 3 +12/-12 5 4 Thru 5" +8/-8 3 Rect.: 2, Sq.: 3 +16/-16 5 4 Thru 6" +8/-8 3 Rect.: 2, Sq.: 3 +16/-16 5 4 Thru 7" +10/-10 4 4 +20/-20 6 6 Thru 8" +10/-10 4 4 +20/-20 6 6 Thru 10" +12/-12 4 4 +24/-24 6 6 Thru 12" +14/-14 4 4 +28/-28 7 6 Thru 16" +18/-18 5 4 +36/-36 8 6 Thru 28" +20/-20 6 4 +44/-44 10 6 Not Available from Webber B89.1.9 Grade AS1 Not Available from Webber B89.1.9 Grade AS2 Size Tolerance Variation in Length Tolerance Flatness Tolerance Size Tolerance Variation in Length Tolerance Flatness Tolerance Thru .050" +12/-12 6 6 +24/-24 12 10 Thru .400" +8/-8 6 6 +18/-18 12 10 Thru 1" +12/-12 6 6 +24/-24 12 10 Thru 2" +16/-16 6 6 +32/-32 12 10 Thru 3" +20/-20 6 6 +40/-40 14 10 Thru 4" +24/-24 8 6 +48/-48 14 10 Thru 5" +32/-32 8 6 +64/-64 16 10 Thru 6" +32/-32 8 6 +64/-64 16 10 Thru 7" +40/-40 10 7 +80/-80 16 10 Thru 8" +40/-40 10 7 +80/-80 16 10 Thru 10" +48/-48 10 7 +104/-104 18 10 Thru 12" +56/-56 10 7 +112/-112 20 10 Thru 16" +72/-72 12 7 +144/-144 20 10 Thru 20" +88/-88 14 7 +176/-176 24 10 B89.1.9 Grade 00 exceeds DIN, ISO, BS Grades K Material Coefficients of Thermal Expansion are: Chromium Carbide 4.7 x 10-6 inch/ºF per inch SAE 52100 Steel 6.4 x 10-6 inch/ºF per inch Ceramic 5.5 x 10-6 inch/ºF per inch Suggested Replacement Grades for GGG-G-15C GGG-G-15C Grade Webber Grade B89.1.9 Grade 0.5 LM — 1 AA 0 2 A1 0 3 A AS1 The above replacement grades are suggested in B89.1.9. However, the tolerances specified in GGG-G-15C and B89.1.9 are not exactly the same. Gage blocks meeting B89.1.9 specifications may not meet GGG-G-15C requirements and vice versa. 378 S t arrett -W ebber G age B locks