'40s-'60s S-K socket marking timeline help?

[Electricquad]

Hi, new here. I am trying to assemble a vintage s-k socket set. I have come across some variations in the markings of post "sk-chrome" but pre "sk-wayne" marked sockets. I have 2 sets from the half matte half chrome style. One set marked "SK" with no USA and one marked "SK USA". For a 7/8 the "SK usa" is 143.3 grams and the "SK" is 130.7 grams. Anyone have thoughts on which came first in the production history? Pic of sockes attached.

 

[r_olson_06]

Hi, new here. I am trying to assemble a vintage s-k socket set. I have come across some variations in the markings of post "sk-chrome" but pre "sk-wayne" marked sockets. I have 2 sets from the half matte half chrome style. One set marked "SK" with no USA and one marked "SK USA". For a 7/8 the "SK usa" is 143.3 grams and the "SK" is 130.7 grams. Anyone have thoughts on which came first in the production history? Pic of sockes attached.

As follows
SK Chrome with knurled base.
SK with knurled base
SK Wayne with knurled base.
SK Wayne with smooth base


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[Oldtuleguy]

I think he wants to know if any variation in sk knurled base. Only variation I have seen is some wartime stuff with no chrome.

 

[Electricquad]

Right, in the example in the pic I have two 'sk' knurled base sockets one with 'usa' one without.

 

[Oldtuleguy]

Are any of them hot forged? Those would be heavier and later

 

[Electricquad]

How would I tell? Apologies if the answer should be obvious.

 

[Oldtuleguy]

Look in broached end of socket. Will be a roll of metal at the bottom if hot forged.

 

[Electricquad]

Ok, so all of the 'usa' sockets are hot rolled. Some of the non-usa sockets are also hot rolled, but more of them have the kind of machined groove at the end of the broach you see in the second pic.

 

[Oldtuleguy]

Older are cold broached. I am not sure on usa will have to look at some of my sets later

 

[Electricquad]

So is that machined groove on the non-USAs ... Cold broach? Something else? Thanks for looking at this with me.

 

[Oldtuleguy]

That's where they clean out the chips from the broaching

 

[Oldtuleguy]

From left to right, oldest to newest, sk knurled base ca.1940, sk knurled base war finish ca.1944, sk knurled base usa pre-wayne, sk wayne knurled base usa.

 

[Electricquad]

Cool, thanks. So the SK USA is a post war logo. Any insight as to why/when they stopped deburring the broach? Are yours deburred pre war and burred post?

 

[Oldtuleguy]

Post war (early 50s, possibly coinciding with lectrolite alliance?) up to wayne ( 1965? Or so). Have not closely studied the broaching question, perhaps someone else here on the forum has more info on that ...

I do think the groove is cut before the cold broaching and is there to catch the chips. If hot broached most manufacturers just leave the molten roll in place. Sk seems to have cleaned theirs up a bit. I have always assumed no groove=hot broached.

 

[Electricquad]

So, I guess the take away from this is that I have at least 2 sets I need to assemble.

 

[Oldtuleguy]

That's the fun part!