Og Screws

I've seen previous posts about the original hex head screws with the indented heads asking what people are using. My experience is with a '53 Willy's M38A1 and a '60 CJ5 which both use quite a few 1/4" screws in the floor panels and other items. 3/8" are also sprinkled in.

There a plenty of flat top hex heads but the indented heads are more difficult to find. After searching I found several offerings on military vehicle parts suppliers but they like to add a premium because they're selling them as military spec. I ordered some from McMaster Carr and some from a vintage Cougar part supplier that I stumbled on. They have a set available for latest 60s oil pans that caught my attention.

I'm posting some comparative photos that compare one of my original screws to what I'm calling cougar screws and the ones from McMaster Carr that I'm calling zinc screws because of the finish.

Both of the screws that I bought are SEMS screws with the washer preinstalled. Cougar screws have solid washers and the zincs come with an outward star washer.

My original screws are 3/8” and 5/8” in length. The cougar screws came in at 5/8". The zincs came in various lengths. I went with 3/8" and 3/4" inch. I can't remember if the 5/8” was available.

Head heghts varied. My original screws' heads measured .17" thick. Cougars are .21" and the zincs measured at .18" on the 3/8" long screws and .185" on the 3/4" long screws.

The imprint on top of the originals is a series of rings. The cougars have a B and the zincs are plain.

My original washers are relatively thin while the cougar washers are thicker than typical. The star washers on the zincs are what you would expect.

Another large difference between the original screws and the others are the newer screws are the hex heads are more rounded. For some reason that part is the most disappointing for me.

Do here are a series of pics. Whenever I photographed all 3 together I lined them up left to right with the original, cougars and zincs. There are also some pics with just the original and one of the others. You should be able to tell which is which.

Lastly, I painted some to show how they'll finish. The each have 1 coat if primer and 1 coat of the the finish.

(In case you're wondering, in some pictures they're sitting on top of magnets.)