CENTERLESS GRINDING ALLOWANCES
Minimum allowance for removal of OD imperfections | ||||||
Finished OD Inches | 0.125 and Under | Over 0.125 to 0.180 | Over 0.180 to 0.230 | Over 0.230 to 0.360 | Over 0.360 to 0.460 | Over 0.460 to 0.580 |
Up to 3.000 | 0.012 | 0.014 | 0.016 | 0.020 | 0.022 | |
Over 3.000 to 4.750 | 0.016 | 0.018 | 0.020 | 0.022 | 0.024 | 0.026 |
Over 4.750 to 6.000 | 0.018 | 0.020 | 0.022 | 0.024 | 0.026 | 0.028 |
Over 6.000 to 7.000 | 0.020 | 0.022 | 0.024 | 0.026 | 0.028 | 0.030 |
Over 7.000 to 8.000 | 0.024 | 0.026 | 0.027 | 0.028 | 0.031 | |
Over 8.000 to 10.500 | 0.026 | 0.028 | 0.030 | 0.032 | ||
Over 10.500 to 12.500 | 0.028 | 0.030 | 0.032 | 0.034 | ||
Over 12.500 to 14.000 | 0.030 | 0.032 | 0.034 | 0.036 | ||
Over 14.000 to 15.000 | 0.033 | 0.035 | 0.036 | 0.037 |
NOTE: These allowances plus normal size tolerances must be considered in calculating the size to be ordered.CENTERLESS GRINDINGS
Example #1:
Determine ordering size for tube to be centerless ground to 4.750”OD x .440” wall.Step 1Determine ID size:4.750”finished ODLess 2 x wall thickness (.440”)-.880”3.870”IDStep 2Apply centerless grinding allowances to OD:Finished OD of 4.750” Takes .024” centerless grinding allowance from table14.750”+ .024”4.774”Step 3Add ID and OD tolerance and order:4.774” OD + .013” – .000″ x 3.870″ ID +.000″ -.013