crossthreaded nipple

[bhuch5]

I have an Investarms Hawken with a crossthreaded nipple hole.Hole is already a 1/4x28 .005 OVERSIZE.What are the possible options? Have considered TIG welding the nipple hole and then redrilling and threading or possibly installing a HELICOIL. I would like to retain a standard 1/4x28 nipple for ease of replacement in an emergency.

Thanks for your advise and consideration. Bruce H

 

[jdkerstetter]

Tap for a larger nipple. I know TOW has 7mm and 5/16" nipples and other sizes for this very reason.

I wouldn't have it welded...unknown metal content...hardening, enbrittlement, etc.

Buy a new nipple and the appropriate drill and tap for it and go to a larger nipple.

Enjoy, J.D.

 

[brownie1934]

DITTO!! an't be too carefull. Bob

 

[Bill Hall]

I did have one welded up once after the nipple blew out. I ground out a big concave area and had a friend fill it by TIG welding it. Worked fine, but it was a lot of extra work when I just could have re-tapped for the next sized nipple.

Like the others said, tap for bigger sized nipple. You may need to use a bottoming tap. Bill

 

[necchi]

It's little wonder it's crossthreaded.
An Investarms is Italian made and uses a 6 mm x.75 mm nipple.
And if someone tried an .005 standard thread over size tap the threads are really boogered.
best try an drill it out tap for a helicoil

 

[bob308]

the way i have fixed them is to drill and tap to 3/8x 24. then make a plug loc-tight it in then drill and tap to 1/4 x28 and you are goo to go.

i have seen the heilcoil usd and it works.

 

[Bill Hall]

the way i have fixed them is to drill and tap to 3/8x 24. then make a plug loc-tight it in then drill and tap to 1/4 x28 and you are goo to go.

Hey, I like that idea. :thumbsup: Bill

 

[bhuch5]

Thank you all for your help in this matter.I do not want to go with a larger nipple size.Will give the 3/8 plug and drill and rethread a try. Bruce H

 

[leslie]

Helicoil time,a proven fix in the mechanical trades in high stress situations.

 

[Johnny Too-Tall]

Just order a new nipple and drum they are around 5-10 dollars.

 

[necchi]

Just order a new nipple and drum they are around 5-10 dollars.

There's no "drum" on an investarms,,,