CCKW internal/external tooth (shakeproof) lockwashers

RANGER · Post by **RANGER** » Wed Aug 02, 2006 12:55 pm

They are primarily used to ensure good electrical grounding of bolted sheetmetal and electrical components. They are sometimes prominant in their kocation and makea visual difference in the quality of your restoration. It appears that in WWII the Shake Proof Washers were Zinc plated, and that they are now mostly Cadmium Plated as noted by their use on M-Series trucks. The CCKWS that have been maintained the friendly European Nations up to recently, have a European version of these washers in place of the originals.

Garry · Post by **Garry** » Mon Sep 11, 2006 10:11 am

Hi Ranger,

How do the post war euro washers differ from those used during WWII?

Thanks,

G.O.

RANGER · Post by **RANGER** » Mon Sep 11, 2006 12:50 pm

The difference is "day and night," the European washers have a much finer tooth pattern. I will post pics in a couple days, my wife has the camera, and I have a busy schedule. I have plenty of NOS samples here and may have saved a couple of the European washers. These are not to be confused with the common civilian internal or extenal washers, but just ine Internal/External "Shake Proof" or "Toothed" lockwashers.

Nick Bombini · Post by **Nick Bombini** » Mon Sep 11, 2006 8:43 pm

These were hard to track down but I have a source for them w/ the same tooth pattern of those that I took off my truck.

I order them from MSC industrial supply. http://www.mscdirect.com
You can order a book from them which is free w/ free shipping. The int/ext tooth washer are on page 1940 and are $12.42 for a box of 100 (this is the least you can order) in 5/16" thread size (this is the size of the thread on a 1/2" head on a bolt. This is the standard size on a CCKW). The washers do have zinc plating on them but they are better than nothing.
http://www1.mscdirect.com/CGI/NNPDFF?PM ... &PMCTLG=00

--Nick

RANGER · Post by **RANGER** » Mon Sep 11, 2006 9:22 pm

Thanks for the tip Nick. Some collectors glean these from surplus miscellaneous parts kits for various military trucks. I bought a couple 5 gallon buckets of these at a local salvage company outlet a few years back, and have included a hand full of the 1/4" and 5/16" size as gifts with parts I have sent to collectors.The washers are plated, they will either be zinc or cadmium, depending on the supplier. The CCKW uses #10, 1/4". 5/16", 3/8", 7/16", 1/2", and 5/8". I used to be a metallurgist with the DOT and tested fasteners of all types. It makes a CCKW stand tall when the washers are installed as specified in the TM and ORD9.

RANGER · Post by **RANGER** » Tue Sep 12, 2006 4:16 am

The majority of these washers will be found at the bolt locations of the radiator Guard, hood side panels, the several ground straps located at the radiator, cowl, cab, running boards, engine to chassis and voltage regulator to firewall.

This is sort of related, there are 4 each, 1/4" External Tooth Lockwashers used at the tail lights.