Acme Thread Collar Diameter?

[jim_moses]

Hi all,

I have an inherited spreadsheet that has the following values for an Acme thread 1-5

Major Dia = 1in
Pitch = 0.2
Collar Diameter = 1.2in

I have looked online and do not see "Collar Diameter" value, is it a calculated value?
The spreadsheet I have does not have a formula for it and list it as an input.

They are using this along with a worm gear calculation to calculate Load Available in Tons.

Any insights would be helpful

Regards,
Jim

[joe_boggs]

I have never seen "Collar Diameter" as a feature in any thread standard. I suspect that the author of the spreadsheet was referring to some special collar that his company used in their particular thread arrangement. That's the problem with using unverified sources and assuming they represent some standard. My copy of Machinery's Handbook (24th edition) has ASME Acme Thread Standards on page 1604. Get yourself a copy of that absolutely invaluable book.

[jim_moses]

Hi again,

Have a few versions of it all the way back to version 5, and that term does not exist, hence me inquiring about it here.

I was hoping someone might have some insights.

Nothing like playing detective behind someone who was smart enough to make a spread sheet, but not leave the source materials that the conclusions are based on.

Regards,
Jim