CollectingSnapOn.com

Why is it some Snap On sockets look like they were all chrome but then ground off and blackened? I usually see this on 3/8 drive.

some older impact sockets are like that. what else?

This is the only picture of some I could find on Google but what does the black stripes mean? These have part numbers as normal chrome sockets but for some reason the chrome was stripped from those spots and blackened.

The bands indicate they are metric sizes. They were marked that way in the 70's and maybe early 80's when imports started to become very popular. It's not just 3/8 sizes - I also have 1/4, 1/2 and one 3/4 marked that way.

The ones in the picture are SAE. I could see if this is was what they did before they started putting the ridges around the metric but I have seen this on metric and SAE?

Never seen the black bands in SAE sizes. I favor this style so I'm always on the lookout for them.

I just checked the 73, 75 and 79 catalogs. The 73 and 75 shows them in metric sizes but not SAE. The 79 shows a knurled band where each of the black bands is in the metric sizes so they were discontinued by 79. I believe they still mark the metric sockets with the double knurled bands.

I enjoy these as well. I have a set I now use sparingly, as the warranty replacements are a different style.