1/4-40 UNS Class 3 thread specs w/tolerances

[specfab]

I'm looking for an already-existing data set for UNS threads that includes Class 3 dimensions and tolerances for internal and external threads. My specific need is for 1/4-40 at the moment, but if anyone has such a collection of info, or can direct me to a chart, that would be grand.

Machinery's Handbook (at least 23rd edition) contains only Class 2 specs for 1/4-40. I suspect I can work out the numbers, but it will require some figgerin' and extrapolatin', I reckon. If this work has been done already, it will save me some time. I have a go/no-go plug gage as well, which has numbers, but I would like to see the tolerances that apply when manufacturing the threads. Thanks for any help --

 

[Gordon B. Clarke]

I'm looking for an already-existing data set for UNS threads that includes Class 3 dimensions and tolerances for internal and external threads. My specific need is for 1/4-40 at the moment, but if anyone has such a collection of info, or can direct me to a chart, that would be grand.

Machinery's Handbook (at least 23rd edition) contains only Class 2 specs for 1/4-40. I suspect I can work out the numbers, but it will require some figgerin' and extrapolatin', I reckon. If this work has been done already, it will save me some time. I have a go/no-go plug gage as well, which has numbers, but I would like to see the tolerances that apply when manufacturing the threads. Thanks for any help --

This programme is well worth the price and is USA made Before I got that programme it could take me a while to find sizes and tolerance. Now rarely more than a minute for most threads. BTW you'll need Go/NoGo ring gauges too.

 

[specfab]

Thanks, Gordon -- just what I needed. I'll need to look into that software. Others also recommended it.

 

[The real Leigh]

This programme is well worth the price and is USA made

Hi Gordon,

Looks like a nice program.

Too bad it's only windoze, with no Mac version obviously available.

- Leigh

 

[Triaged]

I've used this a couple of times. Each dimension I double checked was spot on.

UN imperial screw thread calculator

 

[Gordon B. Clarke]

Hi Gordon,

Looks like a nice program.

Too bad it's only windoze, with no Mac version obviously available.

- Leigh

Leigh,

As to whether no Mac version or not I've no idea. It works just great for me. Considering how much time looking through books and standards and then often having to make calculations many use time on then it pays for itself in no time.

If I was to find a fault then it'd be I wish it had many more thread types than it has (and it has very many) but as you know, weird thread types are also "my thing".

Gordon