Threading Question

[redneckswami]

Good afternoon, everybody.
I have a question regarding tapping some threads in nickel silver sheet. I have some .093 thick nickel silver sheet that I want to use to make an end-cap for a small knife. It will be threaded onto 5/16 x 18 threads on the very end of the tang. Question is, will that work with the threads being so coarse. I plan to chamfer the edges of the screw hole, so when the buttcap's in place, I can peen the tang and flare it to fit the chamfer. Handle's secured with a pin and epoxy, so the cap is really just to give the knife handle a finished look. If necessary, I can use 1/4" nickel silver if that would work better, I just want to use the thinner stuff because I like the way it will look on the finished handle. Any advice will be most appreciated!

I'll post pics of the finished knife tomorrow or the next day when I finish it up...

 

[joe-bob]

Think about it, you will have barely one full turn of thread left by the time you chamfer the hole.

A general rule for thread depth is 1.5 x diameter.

 

[SteelSlaver]

I suggest that you solder a nut to the underside of the nickle silver and don't have a hole in the NS. First put the nut on a bolt and the bolt in a drill and then use a grinder to round the nut. Then have the handle material counter sunk so that the nut has room to thread in. If you glue it during final fit up it will never come loose and it doesn't sound like a take apart anyway. When you solder only have the bottom of the nut clean for solder, melt the solder on the NS sheet then place nut on solder and keep the heat on until the solder flows again then stop. If you should get any solder in the treads you can run in a bottom tap to clean up holding on to the nut with vise grips.

 

[12345678910]

I suggest that you solder a nut to the underside of the nickle silver and don't have a hole in the NS. First put the nut on a bolt and the bolt in a drill and then use a grinder to round the nut. Then have the handle material counter sunk so that the nut has room to thread in. If you glue it during final fit up it will never come loose and it doesn't sound like a take apart anyway. When you solder only have the bottom of the nut clean for solder, melt the solder on the NS sheet then place nut on solder and keep the heat on until the solder flows again then stop. If you should get any solder in the treads you can run in a bottom tap to clean up holding on to the nut with vise grips.

That's what I would have recommended.

You can get double deep nuts, called coupling nuts.
(or just create your own with a drill and tap.)

 

[Mahoney]

ib2v4u has the right solution to put threads on the thin metal. My mechanical engineering professor taught us that you need 2 full threads minimum to get full strength from a connection. More were better, but that's the minimum. At 18 tpi that would be .11", a bit more than the .093 stock in thickness

 

[redneckswami]

I really appreciate the feedback a lot, gentlemen! I'll be soldering a nut to the nickel silver. I had forgotten reading about that trick in "The $50 Knife Shop" (one of my favorite knifemaking books). I appreciate the information, and when I get this thing done, I'll post some pics. Have a good evening!