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APEX offers full-service design, engineering and manufacturing to your specifications. Our custom fasteners have enjoyed great success supplying all types and sizes of businesses in most sectors of industry.
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Authorized Distributor for:

Double Washer Sems

prod-double-washer-sems.jpg Screw and washer assemblies, or SEMS screws are generally covered by the specification ASME B18-13 1996.  Typically, double washers consist of a split lock washer and a flat washer. They are readily available in metric sizes. Special double washer sems can be made for application specific needs.

Flat Washer Options are generally divided into a washer series of Narrow, Regular, and Wide Sizes.  The size chart is below.
Lock Washer Options - While typically a split lockwasher; internal tooth lockwashers and external tooth lockwashers can also be assembled.
Material Options are generally steel, stainless steel, and brass.
Finish Options typically correspond to the material type please contact Apex Fasteners for options.

Some Available Stocked Sizes:

Double Washer Sems
Product Number
Thread Length Drive Head Washer O.D. Material Finish
SE02C025PPSF.150SZR
2-56
1/4"
PHILLIPS PAN .150"
STEEL
ZINC RoHS
SE02C025PPSF.160SZR 2-56 1/4" PHILLIPS PAN .160" STEEL ZINC RoHS
SE02C037PPSF.190SZR 2-56 3/8" PHILLIPS PAN .190" STEEL ZINC RoHS
SE02C037PPSF.219SZR
2-56
3/8"
PHILLIPS PAN .219"
STEEL ZINC RoHS
SE02C062PPSF.250SZR 2-56 5/8" PHILLIPS PAN .250" STEEL ZINC RoHS
SE04C025PPSF.215SZR 4-40 1/4" PHILLIPS PAN .215" STEEL ZINC RoHS
SE04C025PPSF.250SZR
4-40
1/4"
PHILLIPS PAN .250"
STEEL ZINC RoHS
SE04C031PPSF.310SZR 4-40 5/16" PHILLIPS PAN .310" STEEL ZINC RoHS
SE04C037PPSF.215SZR 4-40 3/8" PHILLIPS PAN .215" STEEL ZINC RoHS
SE04C037PPSF.250SZR 4-40 3/8" PHILLIPS PAN .250" STEEL ZINC RoHS
SE04C050PPSF.250SZR 4-40 1/2" PHILLIPS PAN .250" STEEL ZINC RoHS
SE06C025PPSF.255SZR 6-32 1/4" PHILLIPS PAN .250" STEEL ZINC RoHS
SE06C031PPSF.150SZR
6-32
5/16"
PHILLIPS PAN .150"
STEEL ZINC RoHS
SE06C031PPSF.312SZR
6-32
5/16"
PHILLIPS PAN .312"
STEEL ZINC RoHS
SE06C037PPSF.312SZR 6-32 3/8" PHILLIPS PAN .312" STEEL ZINC RoHS
SE06C050PPSF.312SZR 6-32 1/2" PHILLIPS PAN .312" STEEL ZINC RoHS
SE08C037PPSF.375SZR 8-32 3/8" PHILLIPS PAN .375" STEEL ZINC RoHS
SE08C050PPSF.375SZR 8-32 1/2" PHILLIPS PAN .375" STEEL ZINC RoHS
SE10F050PPSF.364SZR 10-32 1/2" PHILLIPS PAN .364" STEEL ZINC RoHS
SE10F050PPSF.406SZR
10-32
1/2"
PHILLIPS PAN .406"
STEEL ZINC RoHS
SE10F050PPSF.562SZR
10-32
1/2"
PHILLIPS PAN .562"
STEEL ZINC RoHS


Dimensions of Plain Washers for SEMS, Pan Head, Fillister Head, Hex Head, Hex Washer Head.  Other sizes are available.

Nominal Size / Basic Diam. Washer Series Washer O.D. Washer Thk.
2 / 0.0860 Narrow 0.183"/0.188 0.022"/0.028"
2 / 0.0860 Regular 0.245"/0.250" 0.028"/0.036"
2 / 0.0860 Wide 0.307"/0.312" 0.028"/0.036"
4 / 0.1220 Narrow 0.245"/0.250" 0.028"/0.036"
4 / 0.1220 Regular 0.370"/0.383" 0.036"/0.045"
4 / 0.1220 Wide 0.433"/0.446" 0.036"/0.045"
6 / 0.1380 Narrow 0.307"/0.312" 0.028"/0.036"
6 / 0.1380 Regular 0.433"/0.446" 0.036"/0.045"
6 / 0.1380 Wide 0.557"/0.570" 0.036"/0.045"
8 / 0.1640 Narrow 0.370"/0.383" 0.028"/0.036"
8 / 0.1640 Regular 0.495"/0.508" 0.036"/0.045"
8 / 0.1640 Wide 0.620"/0.640" 0.056"/0.071"
10 / 0.1900 Narrow 0.433"/0.446" 0.036"/0.045"
10 / 0.1900 Regular 0.557"/0.570" 0.036"/0.045"
10 / 0.1900 Wide 0.727"/0.749" 0.056"/0.071"
1/4 / 0.2500 Narrow 0.495"/0.515" 0.056"/0.071"
1/4 / 0.2500 Regular 0.727"/0.749" 0.056"/0.071"
1/4 / 0.2500 Wide 0.993"/1.015" 0.056"/0.071"



APEX FASTENERS, Inc - 15858 Business Center Drive - Irwindale, CA 91706 USA
APEX Fasteners supplies standard and custom screws, nut retainers, shoulder screws, plastites and taptites, all types of rivets, spring steel fasteners and special stampings, sems screws in standard, fractional or metric to electronics, aviation and other OEM industries worldwide. ApexFasteners.com custom manufactures screw machine components for electronic enclosure hardware as well as cold forming and cold headed specials for assembly and production requirements.
Tel: (626) 962-2219 - info@apexfasteners.com
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