Looking for a resource for ACME stub nuts

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 21, 2018

• #1

Hi,

I'm new here and not a professional, so sorry if this really sounds like a newbie or misplaced question...
I'm looking for a 3/4" nut for an ACME thread rod. After some research I found that it is actually a "stub" ACME (threads are about half as shallow as regular ACME threads). The major diameter is 3/4" (actually measured as 0.745"). Internal diameter is 0.643". It is 6 TPI. Based on a chart I found, this seems like a standard 3/4" stub ACME. I need two steel nuts for this rod, but I can't seem to find a source for it. Maybe Grainger has it, but for the price they are asking, I might as well buy a new vise (or two) instead of fixing it...

So I'm not sure if this is the right place for this kind of question. I know that most of you would just mill the nut... Anyway, thanks for any feedback you might have.

Ben

 

M

Miguels244

Diamond

Joined

Mar 27, 2011

Location

Denver, CO USA

• Feb 21, 2018

• #2

McMaster Carr


McMaster-Carr

 

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 21, 2018

• #3

Thanks Miguel. McMaster offers a lot of choice. But I don't see any indication of "stub" ACME threads. Is this hidden in a spec that I don't recognize, or do they not have it?

 

B

BobsSouthbend

Plastic

Joined

Nov 2, 2008

Location

British Columbia

• Feb 21, 2018

• #4

Try Travers tools


Sent from my iPod touch using Tapatalk

 

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 21, 2018

• #5

Thanks Bob. Travers only have larger nuts (starting at 1 1/4") and they don't seem to be stub.

Ben

 

M

Miguels244

Diamond

Joined

Mar 27, 2011

Location

Denver, CO USA

• Feb 21, 2018

• #6

Stub...
Missed that part.

 

sfriedberg

Diamond

Joined

Oct 14, 2010

Location

Oregon, USA

• Feb 21, 2018

• #7

Roton has 3/4-5 stub ACME parts (that's 5TPI, not 6, unfortunately).

 

Whysosharp

Cast Iron

Joined

Apr 8, 2015

Location

CT, USA

• Feb 21, 2018

• #8

You could try contacting a company called Nordex in Brookfield CT. They have things like this. If you have some time I could find the P/N # in their catalogue

 

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 23, 2018

• #9

I took a look and could not find it. I was not familiar with all the terminology, so I may have missed it. If you could locate it, that would be great. It seems very specialized and high precision, so maybe overkill (= $$$), but we never know...

Thanks,
Ben

 

litlerob1

Diamond

Joined

Nov 4, 2013

Location

Utah, USA

• Feb 23, 2018

• #10

Acme not Stub.

The thread height of an Acme thread is .5 x pitch, so half the pitch is the difference from Major to Minor. A Stub Acme is just slightly less than that, NOT

(threads are about half as shallow as regular ACME threads)

Click to expand...

but I think it is probably Acme, not Stub Acme.

We really would need to see a picture at least, preferably of the profile (comparator) to determine which one it is.

Were it me, I would just rebuild whatever you are doing with Acme hardware (even if it is Stub Acme, replace it). Acme all-thread is readily available and nuts too.

R

 

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 26, 2018

• #11

Hi,

Here are all measurements I took from the thread:
Major diameter (external): 0.745"
Minor diameter (internal): 0.643"
Thread height: (0.745 - 0.643)/2 = 0.051"
TPI: 0.167" pitch = 6
thread width (top): 0.071"
thread width (bottom): 0.081"

According to the table found here on Engineers Edge, this looks like a stub ACME:
ACME Stub Threads Size Designation Table Chart | Engineers Edge

Here is a picture of the thread:


Ben

 

litlerob1

Diamond

Joined

Nov 4, 2013

Location

Utah, USA

• Feb 26, 2018

• #12

Yep, I agree, I think it's Stub Acme too.

The general purpose of Stub Acme thread is a thin walled Box. So I think you are going to have to build one, or get someone to build one for you. We have a commerce section if you want to submit an RFQ.

I tried to find a tap off the shelf and couldn't, people will make you the tap. But single point threading will be the easiest cheapest way to make one. You can get Top Notch threading inserts from several different vendors. Vargus I believe, Toolflo for sure.

R

 

H

HalfReal

Plastic

Joined

Feb 21, 2018

• Feb 26, 2018

• #13

Thanks a bunch for all the great information.
Now I am confident on what I need, if I decide to get it built.

Cheers,
Ben