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. Metric System: Tolerances expressed in micrometers (0.001mm) Order Webber Grade LM Order Webber Grade A1 B89.1.9 Grade 0 Order Webber Grade AA B89.1.9 Grade 00 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 0.5mm +.03/-.03 .03 .03 +.10/-.10 .05 .05 +.14/-.14 .10 .10 Thru 10mm +.03/-.03 .03 .03 +.07/-.07 .05 .05 +.12/-.12 .10 .10 Thru 25mm +.04/-.04 .03 .03 +.07/-.07 .05 .05 +.14/-.14 .10 .10 Thru 50mm +.05/-.05 .03 .03 +.10/-.10 .06 .05 +.20/-.20 .10 .10 Thru 75mm +.08/-.08 .03 .03 +.12/-.12 .07 Rect (.05), Sq. (.07) +.25/-.25 .12 .10 Thru 100mm +.10/-.10 .03 .03 +.15/-.15 .07 Rect (.05), Sq. (.07) +.30/-.30 .12 .10 Thru 125mm +.20/-.20 .08 Rect (.05), Sq. (.07) +.40/-.40 .14 .10 Thru 150mm +.20/-.20 .08 Rect (.05), Sq. (.07) +.40/-.40 .14 .10 Thru 175mm +.25/-.25 .09 .10 +.50/-.50 .16 .15 Thru 200mm +.25/-.25 .09 .10 +.50/-.50 .16 .15 Thru 250mm +.30/-.30 .10 .10 +.60/-.60 .16 .15 Thru 300mm +.35/-.35 .10 .10 +.70/-.70 .18 .15 Thru 400mm +.45/-.45 .12 .10 +.90/-.90 .20 .15 Thru 500mm +.50/-.50 .14 .10 +1.1/-1.1 .25 .15 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 0.5mm +.30/-.30 .16 .15 +.60/-.60 .30 .25 Thru 10mm +.20/-.20 .16 .15 +.45/-.45 .30 .25 Thru 25mm +.30/-.30 .16 .15 +.60/-.60 .30 .25 Thru 50mm +.40/-.40 .18 .15 +.80/-.80 .30 .25 Thru 75mm +.50/-.50 .18 .15 +1.0/-1.0 .35 .25 Thru 100mm +.60/-.60 .20 .15 +1.2/-1.2 .35 .25 Thru 125mm +.80/-.80 .20 .15 +1.6/-1.6 .40 .25 Thru 150mm +.80/-.80 .20 .15 +1.6/-1.6 .40 .25 Thru 175mm +1.0/-1.0 .25 .18 +2.0/-2.0 .40 .25 Thru 200mm +1.0/-1.0 .25 .18 +2.0/-2.0 .40 .25 Thru 250mm +1.2/-1.2 .25 .18 +2.4/-2.4 .45 .25 Thru 300mm +1.4/-1.4 .25 .18 +2.8/-2.8 .50 .25 Thru 400mm +1.8/-1.8 .30 .18 +3.6/-3.6 .50 .25 Thru 500mm +2.2/-2.2 .35 .18 +4.4/-4.4 .60 .25 B89.1.9 Grade 00 exceeds DIN, ISO, BS Grades K Material Coefficients of Thermal Expansion are: Chromium Carbide 8.5 x 10-6 m/ºC per m SAE 52100 Steel 11.5 x 10-6 m/ºC per m Ceramic 9.9 x 10-6 m/ºC per m 379 starrett.com S t arrett -W ebber G age B locks