Washer Concentricity
Subject: Washer concentricity.
Scope: To establish common practice for specifying tolerances of inside diameter concentricity of washers.
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
|
Wall Thickness
Subject: Wall Thickness
Scope: To establish common practice for specifying acceptable limits
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
|
Flatness
Subject:Flatness
Scope:To establish common practice for specifying acceptable limits for flatness on flat washers
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
|
Burrs
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
|
Protruding Fibers
Subject:Protruding Fibers
Scope:Establish common inspection parameters
Fibrous ends shall be permitted on non-metallic material provided they are attached to the parent material
and cannot be dislodged with normal air pressure (approx. 20psi) and do not exceed 50% of material
thickness in length or .10, whichever is less
Seastrom Manufacturing Co., Inc.
456 Seastrom St., Twin Falls, ID 83301
|
Date:
1-29-19
|
Data Sheet No.
|
Measuring Washer Dimensions
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
|
Methods of Measurement
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
|
Interpretation of Limits
Subject: Interpretation of Limits
Scope: Establish common inspection parameters
All limits are absolute. Dimensional limits, regardless of the number of decimal places, are used as if
they were continued with zeros.
EXAMPLES:
| 12.2 |
MEANS |
12.20...0 |
| 12.0 |
MEANS |
12.00...0 |
| 12.01 |
MEANS |
12.010...0 |
ASME Y14.5-2009
|
Date:
3-27-09
|
Data Sheet No.
P. 26
|