Recessed hex head clearance question.

[Stedlin]

Is there a standard for recessed hex head screw counterbore clearance for sockets?

In other words the difference between the socket OD and the counterbore ID.

 

[rlitman]

I wish. Every manufacturer has different socket wall thickness dimensions, with the thinner ones being universally more expensive.

The first way I read your post, I thought you were talking about recessed hex cap screws, which of course have standard head sizes and counterbores, but sockets don't come into play.

 

[kjbenner]

I don't think I've seen a table for it. Although it may exist it at least doesn't seem as ubiquitous as the ones for socket head cap screws.

If you want a starting point, I'd look at Proto sockets. They tend to be some of the fatter ones, and they list the socket ODs in their catalog: https://www.protoindustrial.com/en/...2dc35494_Proto®-1|2"-Drive-Sockets---6-Point/

 

[PCustoms]

I don't think I've ever seen a recessed hex head.

If you are designing something, use a shcs.

 

[Stedlin]

Thanks for the replies.
I have seen recessed hex heads. Once in a air compressor head for example.
It’s not just counterbores but clearance that I’m wondering about. An example would be a hex head that is adjacent to a feature that could cause interference with the socket.

 

[alex71]

Not for hex heads. That's what SHCS are for.

Socket Head Cap Screw Wrench Sizes

ASMC Industrial offers the best selection of industrial bolt and nut fasteners. View our information on socket head cap screw wrench sizes.

www.asmc.net

 

[Stedlin]

Not for hex heads. That's what SHCS are for.

I’ve been designing products using socket head cap screws for over 50 years. I am working on an idea for a new type of socket wrench.

 

[alex71]

gotcha. There's no standard, because there is no standard for socket wall thickness. If I was doing this I would try to be conservative and allow for as much space as possible around the head of the fastener...

 

[Stedlin]

My current design is a 1/16” larger in OD than a Proto. Unfortunately I have no way of knowing if this will be an issue.

 

[alex71]

i would think using a cheap import impact socket as your guide would cover you. those are normally thicker than good ones, and certainly thicker than any chrome socket

 

[Stedlin]

Thanks for the suggestion.

 

[rlitman]

i would think using a cheap import impact socket as your guide would cover you. those are normally thicker than good ones, and certainly thicker than any chrome socket

Impact sockets do always have thicker walls than chrome, with the cheapest ones usually being the thickest.

 

[AdAstra]

There are certainly industry standards for max OD of a socket.

ASME B107:110 is one that most US-sold tools would adhere to.

ISO 2725-1 covers metric sockets.

Machinery's Handbook also lists wrench and socket clearances.

 

[Stedlin]

Exactly what I was looking for. Thanks very much.

 

[laser3kw]

whoops! bad link

 

[laser3kw]

Exactly what I was looking for. Thanks very much.

Here is a resource I used when I was doing Engineering. Create an account for more options:
Icrank machine design guide wrench clearance (link)
Icrank apps (link)

 

[larry_g]

Machinery's handbook has standards for wrench clearances. At least the older ones that I have do.

lg
no neat sig line

 

[PCustoms]

Machinery's handbook has standards for wrench clearances. At least the older ones that I have do.

lg
no neat sig line

You know how I know you didn't read the thread.....

 

[larry_g]

You know how I know you didn't read the thread.....

Please inform me how you think you you know? BTW your wrong...

 

[PCustoms]

Please inform me how you think you you know? BTW your wrong...

Well it's already been said that it's in there, and the tables were posted....

 

[Stedlin]

I seem to have misplaced my copy of the Machinery's handbook 16th edition that I got new in 1972. I'm sure it's around here somewhere unless of course I let someone borrow it.
I have been able to revise my design and make it work within the specification so I'm very excited about that.
Thanks for all the help guys.

 

[PCustoms]

I seem to have misplaced my copy of the Machinery's handbook 16th edition that I got new in 1972. I'm sure it's around here somewhere unless of course I let someone borrow it.

I've been involved with a few parts over the years where the designer should have borrowed a copy.

Hope you find yours!

 

[AdAstra]

Here's the relevant page from the 26th Edition, which doesn't tabulate metric clearances, but they are easy enough to figure out from the socket max ODs posted previously, looks like the latest edition has it, they add about 1.5 mm to the socket max OD.

 

[Stedlin]

Referring to this ASME spec:
The very first size I examined has a discrepancy.

11 mm and 7/16 only differ by .0045” yet the max diameter nut end is .683” for the 7/16” and 16.75mm (.659”) for the 11 mm.

.024” difference?

 

[AdAstra]

These are generally voluntary industry consensus specs drafted by committee, codifying products that were already in production. It’s possible some old tool company had long been making its inch sockets to that large size, and the spec might have been written reflect that. Hard to know, but one possibility. For instance you can see this as an artifact on the drive end max diameters, where they probably polled companies who used the same pre-broach blank for various sizes, and used the largest.

 

[Stedlin]

I don't think I've ever seen a recessed hex head.

If you are designing something, use a shcs.

It seems that the OD specs for sockets are much tighter for hex screws in counterbores. If there are no recessed hex screws than the sockets can be quite a bit larger.
The only hex head screws I recall seeing in a counterbore was on an air compressor so I don’t think it’s very common.

 

[Wolley]

I have seen hex flange head bolts in a counterbore. On the spindle to hub bolts on 2500 gm trucks

 

[Junkdrawer Dog]

Machinery's handbook has standards for wrench clearances. At least the older ones that I have do.

lg
no neat sig line

Haha! Machinery's Handbook! I used to hate lugging that thing to college classes in machine design and drafting. Now, some forty odd years later, I'm thinking about acquiring another copy for a little light reading at bedtime!