Tolerances

High Speed Steel End Mills


Cutting Diameter Tolerances
End Mill Style Number
of Flutes
Type/Range Niagara Cutter Tolerance Corresponding List Numbers
Double-End
Finishers
2, 3 & 4 Center Cutting (+.0000/-.0015) D201, D400, DA206, DB215, DB260, DBS217, DC402, DL213, DL418, DR209, DR416, DS211, DS420, DTF310
4 Flute Non-Center Cutting Flute Smaller than Shank (+.001/-.000) D400
Shank & Flute Same Size (+.0000/-.0015)
Single-End
Finishers
2 Stub Length (+.0000/-.0015) A208, A337, AB337, AB910, ACB337, AL337, S203, S404, SB207, SB470, SC406, SEB270, SEL250, SK204, SLRB601, SLRC602, SR208, SR414, STF320, SLR600
2, 3, 4, 6 & 8 All Except Heavy Duty (+.001/-.000)
Metric Finishers
With Inch Shanks
2 & 4 All Sizes (+.001/-.000) SMM830, SMM850
Ball End All All Sizes Ball Radius Tolerance: Flute Dia/2
Shank Diameter Tolerances
End Mill Style Niagara Cutter Tolerance
All Inch Shanks (-.0001 / -.0005)
Length-Of-Cut Tolerances
End Mill Style Niagara Cutter Tolerance
All (+.031 / -.000)
Overall Length Tolerances
End Mill Style Niagara Cutter Tolerance
All (+.062 / -.000)
TIR Condition
End Mill Style Cutting Diameter Niagara Cutter Tolerance
All .005 thru .030 0.0001 Max
.031 thru .060 0.0002 Max
.061 thru .111 0.0003 Max
.112 and above 0.0010 Max
Back Taper
End Mill Style Niagara Cutter Tolerance
All .0005 Max Back Taper Per Inch permissible. Not to exceed the Cutting Diameter Tolerance.


All dimensions are in inches unless otherwise noted.