Tolerances on Openings

Tech. Info

Tolerances on Openings

The tolerance on the opening is the allowable deviation for the stated hole size in a perforated sheet or plate. The tolerance of the opening is a measurement of the minimum opening size only, and does not refer to the dimensions of the hole as it progresses through the thickness of the sheet.

Many factors can influence the size of the hole including the type and thickness of material, the punch and die clearance, and the use of plasma or oxy-fuel cutting. During punching, the top surface of the material will “rollover” resulting in a finished hole that is slightly smaller than the punch that created it. The amount of “rollover” usually increases with material thickness, but varies greatly with material type and die clearance.

The chart below is the standard tolerance for hole size that is applied to all orders unless noted otherwise. Please contact us to discuss any special requirements you may have.

Tolerances on Openings
Nominal Decimal Hole Size
Hole Size Hole Size Tolerance
     
.5 mm   ±.002
  0.023 ±.002
  0.027 ±.002
  0.032 ±.002
1 mm 0.039 ±.003
  0.045 ±.003
  0.055 ±.004
  0.066 ±.004
  0.078 ±.005
3/32" 0.094 ±.005
7/64" 0.109 ±.006
1/8" 0.125 ±.006
  0.127 ±.006
5/32" 0.156 ±.007
3/16" 0.188 ±.008
7/32" 0.219 ±.009
1/4" 0.250 ±.009
17/64" 0.266 ±.009
5/16" 0.312 ±.010
3/8" 0.375 ±.010
7/16" 0.438 ±.011
15/32" 0.469 ±.011
1/2" 0.500 ±.011
17/32" 0.531 ±.012
9/16" 0.562 ±.012
5/8" 0.625 ±.013
11/16" 0.688 ±.014
3/4" 0.750 ±.015
13/16" 0.812 ±.016
7/8" 0.875 ±.018
15/16" 0.938 ±.019
1" 1.000 ±.020
1 1/16" 1.062 ±.021
1 1/8" 1.125 ±.023
1 3/16" 1.188 ±.024
1 1/4" 1.250 ±.025
1 3/8" 1.375 ±.028
1 1/2" 1.500 ±.030
1 5/8" 1.625 ±.033
1 3/4" 1.750 ±.035
1 7/8" 1.875 ±.038
2" 2.000 ±.040
2 1/8" 2.125 ±.043
2 1/4" 2.250 ±.045
2 1/2" 2.500 ±.050
2 3/4" 2.750 ±.055
3" 3.000 ±.060
3 1/4" 3.250 ±.065
3 1/2" 3.500 ±.070
3 3/4" 3.750 ±.075
4" 4.000 ±.080
4 1/4" 4.250 ±.085
4 1/2" 4.500 ±.090
5" 5.000 ±.100