Internal Tooth Lock Washer: Dimensions & Specifications

Internal Tooth Lockwasher Drawing

Internal Tooth Lock Washer (ASME B18.21.1-2009)

Nominal Washer Size

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A

B

C 

Inside Diameter (ID)

 Outside Diameter (OD)

 Thickness (TH)
Max Min Max Min Max Min
#2 0.086 0.095 0.089 0.200 0.175 0.016 0.010
#3 0.099 0.109 0.102 0.232 0.215 0.016 0.010
#4 0.112 0.123 0.115 0.270 0.245 0.018 0.012
#5 0.125 0.136 0.129 0.280 0.255 0.020 0.014
#6 0.138 0.150 0.141 0.295 0.275 0.022 0.016
#8 0.164 0.176 0.168 0.340 0.325 0.023 0.018
#10 0.190 0.204 0.195 0.381 0.365 0.024 0.018
#12 0.216 0.231 0.221 0.410 0.394 0.027 0.020
1/4 0.250 0.267 0.256 0.478 0.460 0.028 0.023
5/16 0.312 0.332 0.320 0.610 0.594 0.034 0.028
3/8 0.375 0.398 0.384 0.692 0.670 0.040 0.032
7/16 0.438 0.464 0.448 0.789 0.740 0.040 0.032
1/2 0.500 0.530 0.512 0.900 0.867 0.045 0.037
9/16 0.5625 0.596 0.576 0.985 0.957 0.045 0.037
5/8 0.625 0.663 0.640 1.071 1.045 0.050 0.042
3/4 0.750 0.795 0.769 1.245 1.220 0.055 0.047
7/8 0.875 0.927 0.894 1.410 1.364 0.060 0.052
1 1.000 1.060 1.019 1.637 1.590 0.067 0.059
1 1/8 1.125 1.192 1.144 1.830 1.799 0.067 0.059
1 1/4 1.250 1.325 1.275 1.975 1.921 0.067 0.059
 
1/8  Pipe 0.425 0.410 0.615 0.595 0.022 0.017

 

Description

A tough circular washer with twisted prongs or "teeth" extending inward from the washer's inside rim.
Applications/
Advantages

It's preferred when completed that the appearance is vital and the teeth under the head of the screw must be hidden;
it is also suggested for use with smaller heads such as fillisters.

Material

Steel: SAE 1050 - 1065 spring steel.
18-8 Stainless: SAE 301 - 305 stainless steel.
316 Stainless: SAE 316 stainless steel.
410 Stainless: SAE 410 stainless steel.
Hardness

Steel: Rockwell C40 - 50
18-8 Stainless: Annealed 88 minimum Rockwell B, 1/4 hard through full hard Rockwell C20 - 45
410 Stainless: Rockwell C40 - 50
Plating

See the table above for more information on the plating of steel lock washers.