Workmanship Acceptance Standards

Subject: Washer concentricity.
Scope: To establish common practice for specifying tolerances of inside diameter concentricity of washers.

O.D. and I.D. tolerances (decimal inches)
O.D. +
0.062 to 0.311
0.312 to 0.374
0.375 to 0.625
0.626 to 0.922
0.923 to 2.750
2.751 to 5.000
5.001+
0.000
0.008
0.015
0.015
0.030
0.045
0.065
0.005
0.005
0.005
0.007
0.007
0.010
0.010
I.D. +
0.032 to 0.124
0.312 to 0.249
0.260 to 0.625
0.626 to 1.500
1.501 to 2.625
2.626+
0.000
0.008
0.015
0.030
0.045
0.065
0.005
0.005
0.005
0.007
0.010
0.010
Concentricity (decimal inches)
I.D. Range Concentricity in T.I.R.
0.032 to 0.124
0.125 to 0.249
0.250 to 0.625
0.626 to 1.500
1.501 to 2.625
2.626+
0.005
0.013
0.020
0.037
0.055
0.075

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1001

Subject: Wall Thickness
Scope: To establish common practice for specifying acceptable limits for wall thickness on flat washers

Wall Thickness Table
O.D. Range Minimum Wall Thickness
Inches Millimeters Inches Millimeters
0.1875-0.375
0.375-1.000
1.000-2.000
2.000-3.000
3.000-5.000
4.76-9.5
9.5-25.0
25.0-51.0
51.0-76.0
76.0-127.0
0.0625
0.09375
0.125
0.1875
0.250
1.6
2.4
3.2
4.76
6.35
For: Minimum Wall:
•low carbon steel annealed
•1050 high carbon steel annealed
•copper alloys– all tempers
•aluminum alloys– all tempers
2 times metal thickness but not less than above chart
•stainless steel annealed blue steel*
•pre-tempered high carbon steel*
3 times metal thickness but not less than above chart
*NOTE: contact your WASHER DIVISION member for exemptions. Special tooling or set-up procedures sometimes permit less wall. There is a limit of up to 0.020 inch maximum thicknes of blue steel and pre-tempered high carbon steel.

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1002

Subject: Flatness
Scope: To establish common practice for specifying acceptable limits for flatness on flat washers
Measuring variation from flatness
Variation from flatness is measured by laying the part on a surface plate with the convex side up and measuring the maximum rise. The "roll over" on the edges of the washer is not to be measured.

Outside Diameter (inches) Flat within T.I.R.
0.000-1.000
1.000+
0.010
0.010/inch

Note: Washer faces shall be parallel within 0.002/inch.
Parts that are relatively thin in relation to their outside diameter may be subjected to the following pressure when measuring flatness

Material Thickness
(inches)
Outside Diameter
(inches)
Pressure
(ounces)
0.001-0.005
0.006-0.010
0.011-0.020
0.021-0.030
0.031
0.040
0.000-0.499
0.500-0.999
1.000-1.999
2.000-2.999
3.000+
2
4
8
16
24

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1003

Subject: Burrs
Scope: To establish common practice for specifying acceptable limits for burrs on flat washers

Requirement Material Thickness
(inches)
Allowable burr
(inches)
When deburring is not specified 0.001-0.004
0.005+
0.0005
10%of thickness
When deburring is specified as "must be free of burrs" 0.001-0.004
0.005-0.030
0.031+
0.0003
0.0005
2% of thickness

*Burrs are ragged, usually sharp, protrusions on edges of metal stampings.

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1004

Subject: Measuring Washer Dimensions
Scope: To establish common inspection parameters

Feature Size: This is to be measured only in the cut portion of the hole and the cut portion of the outside diameter.

Shear or Burnished Land: This is a burnished area which is approximately one third of the material thickness.

Break: This is an area which is tapered about three degrees. This area has a rougher surface than the cut area.

Roll Over: This is a natural consequence of the punching process and the mechanical properties of the material being punched.

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1005

Subject: Methods of Measurement
Scope: To establish common practice for measurement of washers.

Outside Diameter (O.D.): Use micrometer at shear or burnished land.

Inside Diameter (I.D.): Use plug gauges.

Thickness: Use micrometer measurement exclusive of burr.

Flatness (for flat washers only): Washer must pass between two parallel surfaces whose distance is equal to the allowable material tolerance plus the allowed flatness tolerance.

Burr: Use a dial indicator as it has a minimum amount of pressure, will not crush the burr, and gives the most accurate reading

WASHERS DIVISION of the
Precision Metalforming Association
27027 Chardon Road, Cleveland, Ohio 44143
Date:
2-1-92
Data Sheet No.
WD1006


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