Tolerance (e.g. "CN M G432" / "CC M T32.51") Hole / Chipbreaker (e.g.
"CNM G 432" / "CCM T 32.51") - 6 - Code Cornerpoint Thickness Inscribed Cornerpoint Thickness Inscribed Letter (inches) (inches) Circle (in) (mm) (mm) Circle (mm) A .0002" .001" .001" .005mm .025mm .025mm C .0005" .005" .001" .013mm .025mm .025mm E .001" .001" .001" .025mm .025mm .025mm F .0002" .005" .0005" .005mm .025mm .013mm G .001" .001" .001" .025mm .13mm .025mm H .0005" .001" .0005" .013mm .025mm .013mm J .002" .001" .002-.005" .005mm .025mm .05-.13mm K .0005" .001" .002-.005" .013mm .025mm .05-.13mm L .001" .001" .002-.005" .025mm .025mm .05-.13mm M .002-.005" .005" .002-.005" .05-.13mm .13mm .05-.15mm U .005-.012" .001" .005-.010" .06-.25mm .13mm .08-.25mm Code Letter Diagram Hole Hole Shape Chipbreaker Type A Yes Cylindrical None B Yes 70-90° double countersink None D Yes Cylindrical None E No None F No Double-sided G Yes Cylindrical Double-sided H Yes 70-90° single countersink Single-sided M Yes Cylindrical, or dbl countersink Single-sided N No None P Yes Cylindrical Hi-double positive Q Yes 40-60° double countersink None R No Single-sided S Yes Cylindrical Hi-double positive T Yes 40-60° double countersink Single-sided U Yes 40-60° double countersink Double-sided W Yes 40-60° double countersink None Z Yes Cylindrical Double-sided hi-double positive