Extractor Socket Sizes, Multiple Size Markings on Same Socket?

[YoshiMoshi3]

I have some extractor sockets

A Duralast spiral extractor shallow socket set that has two sockets with the following stamped on it

• 3/4 " (19 mm)
• 5/16 " (8 mm)

Another socket that I got from Oriley that has sizes

• 5/8 " (16 mm)
• 9/16 " (14 mm)
• 1/2 " (13 mm)
• 7/16 " (11 mm)
• 3/8 " (10 mm)

I know the difference between 3/8 " and 10 mm may be not much of a difference, but in terms of extracting rounded nuts and bolts a 3/8 " extractor socket and a 10 mm extractor socket, may be all the difference in getting off a rounded fastener. Should I interpret the socket as 3/8 " or 10 mm? If I know a 10 mm extractor socket is not tight enough to bite down on a rounded 10 mm socket, a size slightly smaller than 10 mm may be the difference in getting it off, hence a need for 3/8 ". But I don't know what exactly these sockets are supposed to be. Understood that there is some tolerance on the values. But it would still be good to know what the intended machined sizes of the sockets 3/8" or 10 mm? Sorry if I'm not explaining this well.

 

[Ohio Andy]

Sometimes the started sizes do not directly match and you may need subverting a bit larger or smaller depending on the deformation. So I bought the

GEARWRENCH 28 Pc. 1/4" & 3/8" Drive Bolt Biter™ Impact Extraction Socket Set - 84784​

https://a.co/d/e19iW9i

For broken bolts, I have a lot of other things like I have a set from Ridgid and a set from grip edge, And a bunch of extractors that I've either had a while or inherited from my grandfather those are mostly spiral and when I say mostly I think they're all spiral for the older ones.

 

[shoggoth80]

I think they're stamped as usable for either size? Especially regarding the sizes mentioned as they are close. I've always just grabbed whatever fit closest and tapped it on with a hammer. The spiral fluting bites deeper the more you have to crank on it. I run an old Craftsman set. Haven't needed anything fancier yet

 

[cherrybomb]

The numbers stamped are only a recommendation, you look for a reasonable tight starting fit and tap on

 

[pbon]

Yes, a recommendation or suggestion, maybe depending on how big a hammer you have. I had a little set of 4 then upgraded to a set of 8 and now have a set with about 28 sizes. I found that sometimes nothing in the set of 4 or 8 fit well enough to help.

 

[PCustoms]

Your dealing with rusty/broken/rounded hardware.

Find the closest one, bash it on there and unscrew.

 

[YoshiMoshi3]

Thank you. I think it's just a suggestion, like others have said on here? So if my socket with "3/8 (10)" socket is too large, should I bother trying to use an extractor socket that is marked with "3/8" and ONLY "3/8" on it, as it's slightly smaller than 10 mm.

 

[pbon]

It is worth trying. They are fluted inside and maybe a little tapered so pound it on and hopefully it will work.