Barrel Nut - Thread Size and Pitch

[jdgilbert]

Does anyone know the diameter and thread pitch for a standard AR-15 upper receiver barrel nut? I've got a couple ideas I'm kicking around and short of taking my upper apart and measuring I don't have an extra upper or barrel nut handy to check. I know I found some CAD files of the upper receiver before but I don't have capability to open them right now on my computer. If anyone has this handy thanks in advance!

[DDriller]

It is 1.25" x 18tpi Brownell's sells both tap and die.
http://www.brownells.com/.aspx/pid=6...ER_TAPS___DIES

[jdgilbert]

Thanks, I knew it had to be out there somewhere.

[jdgilbert]

Here's a little cheaper one, I'm probably the only nerd looking for one, but whatever.

http://www.hermanscentral.com/produc...teel-13245.cfm

[compshoot61]

Here's a little cheaper one, I'm probably the only nerd looking for one, but whatever.

http://www.hermanscentral.com/produc...teel-13245.cfm

Just a word of caution: The link above is for a METRIC tap. 18mm x 1.25 tpm <----Notice the M!

It is not a 1.25" x 18 tpi tap.

I know because I ordered one without double checking everything. It arrived today and is clearly too small! Hopefully Herman's will take it back and I can get some of my money back.

[jdgilbert]

Sorry about that, I hadn't looked at this thread since then and you're right. I got our detailer/parts orderer at work to check on some of these, the prices were pretty reasonable, I think he uses McMaster-Carr for most of his tooling orders.

Just a word of caution: The link above is for a METRIC tap. 18mm x 1.25 tpm <----Notice the M!

It is not a 1.25" x 18 tpi tap.

I know because I ordered one without double checking everything. It arrived today and is clearly too small! Hopefully Herman's will take it back and I can get some of my money back.

[compshoot61]

Hermans is sending me an RMA. Very friendly on the phone. Didn't give me any grief about returning this. I ordered two from Brownells. One tapered, one bottom. The bottom tap still has about three threads taper. I think I'll grind that down so it really is a "bottom" tap. I'll have to check out McMaster-Carr. Thanks.

[compshoot61]

Tigers or Tide?

[compshoot61]

dealer price at Brownells was close to half what the McMaster-Carr site had listed. McMaster-Carr has a MUCH bigger selection, but I only need one size, so.., Brownells also has the taps and dies for the buttstock, if someone needs them. Even cheaper than the barrel end!

[compshoot61]

Hermans also sent me a link to the correct tap:

http://www.hermanscentral.com/produc...-tap-13560.cfm