I am new to all this, and trying to get my head around the
different threads.
Acme thread is that the one with a very square thread?
TEA have a thread called TRAPEZOIDAL is this the same as ACME?
It has a part number of TR12x3 But iam told this is a standard bolt thread
Can any one put some light on this for me. :rolleyes:

Thanks for all your help.
this is a great forum full of good infomation. :)

Hi Geof,

Trapeziodal Thread is different from ACME although to a quick glance they appear similar.

Is Trapezoidal ok for a CNC machine?
Is ACME better? :)

it might depend a bit on where you are - acme thread is based on imperial and trapezoidal metric - so they serve the same function and you want to go with whatever is available. Neither threads are square, both are trapezoid shaped, there is such a thing as a square thread as well, but the acme has largely replaced it.

The square thread is called Buttress, ACME is kinda halfway between a Buttress and a V-thread.
You may use what you want to build your CNC, but ballscrew is the most appropriate to use.

The square thread is called Buttress, ACME is kinda halfway between a Buttress and a V-thread.
You may use what you want to build your CNC, but ballscrew is the most appropriate to use.

Square thread is square both flanks. Buttress is square one flank and angled on the other.

I live in South Australia Were is the best place to buy ballscrew from? :)

The Bible for this kind of information is the Machinery's Handbook. I highly recommend it to everyone who is in the trade. It has all of the information that you will probably ever need for questions like this. I think the price is now about $175.00 but well worth it.

rgengstrom