[cob]

got a question maybe someone can help
55 degree vs a 60 degree thread
does anyone still do 55 degree thread?

[joeavaerage]

Hi,
unless its a really critical high torque/load thread who cares? The only thread for which there is a clash between UNC and BSW is at 1/2 inch,
the pitches are different.

Craig

[manjitdxb]

The difference is geometry.

[alex441]

It's not a matter for strength - or rather a 60 degree PA nut if fitted on a 55 degree PA bolt would hold well enough for most purposes. Consider bearing: the line bearing of the 60-degree crest to the 55-degree root would lead to instant galling. The whole idea of matching pressure angles is to ensure and area bearing. There is always some mismatch the bearing is never perfect but metal is also a little forgiving. It will deflect and flow to a microscopic extent but not much; certainly not 5 degrees.
If you can't think the problem through in a technical sense, try personally.
Fitting Unified or DIN(?) 60-degree threads to 55 degrees Whitworth is a classic "a guy ole me.." piece of technical idiocy. I'm surprised anyone would seriously consider it - which is a caveat to noobs. Not everyone in an assured manner is worth listening to.

[cob]

thank you for the replies
so i have been looking for a 2 1/4 x 4 tap and for some reason nobody sells them does some know where i can get one?
thank you

[joeavaerage]

Hi,
a 2-1/4 tap will cost a fortune even if you can get one. Not to mention the huge torque you be required to apply to cut the thread.
Can you not cut it on a lathe or mill it?

Craig

[peteeng]

Hi Cob - Do you mean a 2-1/4" diameter 4tpi tap in whitworth? Peter

https://wallersindustrialonline.com/...RoC3qwQAvD_BwE

try these guys Peter

or these in USA - they have 2-1/4x4 tpi in their catalogue
https://www.newmantools.com/taps/tapsbritish.htm

[mactec54]

got a question maybe someone can help
55 degree vs a 60 degree thread
does anyone still do 55 degree thread?

If you have a need or are repairing something then yes anything you want is available I have threading inserts for 55 degree thread cutting and most manufactures still make 55 degree carbide threading inserts and Taps

If you have something that has a 55 degree thread then you will have to make the matching part or make both parts with 60 degree threads

[cob]

thank you guys for all the sudjestion
( 2-1/4" diameter 4tpi tap in whitworth) yes this is the whitworth thread .
yea I dont think i will be buying a tap, its to expensive,

my next question is do you guys know if theres a place that sells nuts that are already threaded to 2-1/4 x 4tpi?

thank you

[mactec54]

thank you guys for all the sudjestion
( 2-1/4" diameter 4tpi tap in whitworth) yes this is the whitworth thread .
yea I dont think i will be buying a tap, its to expensive,

my next question is do you guys know if theres a place that sells nuts that are already threaded to 2-1/4 x 4tpi?

thank you

This company may be able to help they have those big sizes will most likely have to make it

https://www.lawsonproducts.com/catal...jsp.sortByForm