lw27-1Specifications: All commercial and military tooth lockwashers supplied by WCL Company and listed on these pages conform to ASME B18.21.1 and to all applicable specifications as reported by IFI.

  • For use with flat and oval head screws having either 80° or 100° countersunk angles.
  • Where appearance or snagging are important considerations a version with a smooth external flange and internal teeth is available.

82° Countersunk – External Type

Nominal Washer Size Hole Dia. Min. Hole Dia. Max. Outside Dia. Min. Outside Dia. Max. Thickness WCL Part Numbers Cross Reference MS35336-1
Steel Plated
MS35336-1
Stainless Steel
MS35336-1
Bronze Alloy
2 0.089 0.095 0.17 0.183 0.013 CTSK-0086-00-00 1502-00
4 0.113 0.123 0.224 0.238 0.015 CTSK-0112-00-00 1504-00 -3 -5 -55
6 0.14 0.15 0.283 0.298 0.017 CTSK-0138-00-00 1506-00 -9 -11 -56
6 0.142 0.15 0.285 0.3 0.013 CTSK-0138-02-00 1506-02
8 0.167 0.177 0.324 0.34 0.017 CTSK-0164-00-00 1508-00 -15 -17 -57
10 0.195 0.205 0.353 0.372 0.022 CTSK-0190-00-00 1510-00 -21 -23 -58
12 0.22 0.231 0.429 0.447 0.022 CTSK-0216-00-00 1512-00
1/4 0.255 0.267 0.458 0.478 0.022 CTSK-0250-00-00 1514-00 -27 -29 -59
16 0.273 0.287 0.523 0.543 0.025 CTSK-0281-00-00 1516-00
5/16 0.318 0.337 0.603 0.625 0.025 CTSK-0312-00-00 1518-00 -33 -35 -60
3/8 0.383 0.398 0.776 0.801 0.029 CTSK-0375-00-00 1520-00 -39 -41 -61
7/16 0.448 0.463 0.863 0.89 0.035 CTSK-0437-00-00 1522-00
7/16 0.448 0.463 0.89 0.915 0.035 CTSK-0437-02-00 1522-02
1/2 0.512 0.529 0.977 1.007 0.039 CTSK-0500-00-00 1524-00 -51 -53 -63
5/8 0.65 0.675 REF. 1.312 0.051 CTSK-0625-00-00 1528-00

100° Countersunk – External Type

Nominal Washer Size Hole Dia. Min. Hole Dia. Max. Outside Dia. Min. Outside Dia. Max. Thickness WCL Part Numbers Cross Reference MS35336-1
Steel Plated
MS35336-1
Stainless Steel
MS353361
Bronze Alloy
8 0.168 0.176 0.324 0.34 0.015 CTSK-0164-04-00 1508-04 -9 -123
10 0.195 0.204 0.377 0.394 0.017 CTSK-0190-05-00 1510-05 -17 -125
1/4 0.256 0.267 0.473 0.493 0.022 CTSK-0250-05-00 1514-05 -25 -127

82° Countersunk – Internal Flange Type

Nominal Washer Size Hole Dia. Min. Hole Dia. Max. Outside Dia. Min. Outside Dia. Max. Thickness WCL Part Numbers Cross Reference
8 0.207 0.215 0.615 0.635 0.025 CTSK-0164-07-00 1508-07
5/16 0.34 0.362 0.802 0.818 0.029 CTSK-0312-04-00 1518-04*

* For 1/4″ HD screw 1 WCL acquires countersunk washers from our Vendors, and tests to certify performance to MS35336 specifications. Due to manufacturing tolerances some parts do not conform to military specifications. Inquire with WCL sales staff for more information.

82° Countersunk – Internal Flange Type

lw27-2

Screw Size 4 5 6 8 10 12 1/4 5/16 3/8
A 1/8 5/32 11/64 13/64 15/64 1/4 9/32 23/64 27/64
B 9/32 5/16 11/32 25/64 29/64 33/64 37/64 45/64 27/32
C 0.09 0.095 0.1 0.11 0.125 0.155 0.165 0.2 0.245

Countersinking specifications to accommodate 82° flat and oval head screws with WCL Countersunk Lockwashers

Note: Dimensions are approximate.