Tapping threads in thin wall tubing

[ram rod2]

Tapping threads in to thin wall tubing or installing a threaded bung can be a pain. Here's a little trick that I have used. First clean the area were you want the threaded hole. Mark hole location with center punch. Then depending on the size hole you want,take a drift one size bigger than hole and dimple the tube at the center punch location. About 1/16" deep. Weld up the dimple and sand flush.(don"t sand below flush) Remark hole location,drill and tap hole. This will give you more meat to get a better thread count. I have used this process on 5/16" and less holes. You can also use this process for repairing striped threads when resizing is not a option. I suggest that you practice on a some scrap tubing to get welding heat right.

 

[T-Test]

I just use self threading bolt/screw from Fastenal. Same as Total Performance did. Never had any problems coming loose or re tightening.

 

[ram rod2]

Yes they are great for small screws but I would not use them for anything over about 3/16" IMHO

 

[T-Test]

Yes they are great for small screws but I would not use them for anything over about 3/16" IMHO

I use 3/8-5/16-1/4" on all add on parts.

 

[railroad]

Don't over look the rib nut or riv nut insert. The tools and inserts are more common and cheaper. Most nut and bolt suppliers carry the tool and inserts.

 

[choppinczech]

Don't over look the rib nut or riv nut insert. The tools and inserts are more common and cheaper. Most nut and bolt suppliers carry the tool and inserts.

I use them quite a bit in metal and glass. SAE and metric threads with varying grip ranges.

 

[fletcherson]

I like them, but sometimes the top flange prevents a flush fit. Normally not an issue. They are stronger than self tapping screws, imho. They used to be cost inhibitive and the smooth wall type would spin sometimes, usually at a later date when trying to disassemble. The new ones are better.

 

[choppinczech]

Rivet studs are useful too.

 

[Gerry]

I will always weld a plug in thin wall that goes right through and is welded at the other end as well. Well maybe not for a clip or something similar. Just me being over cautious....

 

[railroad]

I put a drop of locktite on the outside of rivnut, in hopes it will stay tight forever.