Threads used in Snap On boxes?

[VolksWomble]

I have a Canadian made Snap On KRA 40” rollcab and top chest. Can anyone tell me what thread is used in

a) the inserts in the top chest which allow the two to be joined together, and

2) the inserts in the Rollcab sides to bolt the handle on with?

They are roughly 1/4” OD, and having assumed (and then confirmed) they weren’t metric (M6), I tried 1/4UNF but they seem to be finer than that…

many thanks in advance
M

[To close this off, after measuring with the thread guages it did turn out to be 1/4-20 (1/4UNC)]

 

[bob15]

Did you try a metric fine thread or see if it is a #12 screw? Or use a threadleaf and get the tpi and go from there.

 

[RTM]

My Snap-on KRA-53B tool chest, 1978 vintage used a fine thread on the handle screws, like 10-32. Pretty sure not 1/4-28. I can go poke about later on, but my bluetooth won't make it to the garage, and the people I'm meeting with will miss me. Yup, 10-32. So maybe yours is a metric fine like Bob said. And I have no idea how to define a metric fine thread.

I thought the KR meant Kenosha Red, so surprised its Canadian made. Not saying you are wrong, just observing.

 

[Walkers]

Try 12-28

 

[bob15]

Try 12-28

Now that is a not used very much thread. I would be more inclined to say 12-24, if a # 12 machine screw.

 

[Walkers]

Now that is a not used very much thread. I would be more inclined to say 12-24, if a # 12 machine screw.

The OP indicated it was finer than a 1/4-28, and while this wouldn’t be finer it would be slightly smaller.

 

[The Cobbler]

maybe a dumb question, but could it just be some paint in the threads causing you the fitment issue?

 

[VolksWomble]

maybe a dumb question, but could it just be some paint in the threads causing you the fitment issue?

Not a dumb question at all, but definitely not the issue as you can see the pitch is much finer than either the UNF or Metric Course threads .

looks like I will need to get the thread gauges and the callipers out. Some of the finer imperial screws are not that common in the UK, so will need to take some more accurate measurements before ordering anything.

 

[bob15]

did you try contacting Snappy? Their website shows a 1/4-20 for the side handle

Snap-on Store

shop.snapon.com

 

[VolksWomble]

that’s a good shout. The Snappy website recognises I’m in the UK and only shows certain parts to me (this is the subject of a saga about changing locks at the moment…) and seemingly the Bolts arent on the parts list you link to. Thank you for pointing them out as 1/4-20 though. I will give a 1/4 UNC bolt a try… I’ve also dug out my thread gauges this evening so will attempt to identify the thread count properly tomorrow!

 

[VolksWomble]

To close this off, after measuring with the thread guages it did turn out to be 1/4-20 (1/4UNC) despite me thinking they were finer, they were in fact coarser than UNF… the eyes lie in poor light!

 

[bob15]

To close this off, after measuring with the thread guages it did turn out to be 1/4-20 (1/4UNC) despite me thinking they were finer, they were in fact coarser than UNF… the eyes lie in poor light!

5 dollar cheater-glasses help too

Glad you figured it out......