4-40 taps

[dlane]

The hole is taped all the way thru so a 4-40 set screw Locks the top button head screw with a Belleville washer under it,
To keep downward pressure on a rotating aluminum top. I’ve made these before after grinding the tap shank to clear the threads but that tap is wore out. I have a taping fixture or a tapmatic 1a I’m hoping to use.
This is California if you want to see a design pm me.
Thanks for the help, advice, thoughts

 

[Kernbigo]

in aluminum use a x-press tap

 

[pdentrem]

Could of used thread forming taps. Soft metals are perfect for this style of making threads.

https://www.mscdirect.com/basicsof/thread-forming-taps

 

[Kernbigo]

Thread forming and x-press are the same thing,that is what they were design for soft material,Besly design that tap when I worked there

Sent from my SM-G900V using Tapatalk

 

[dlane]

Not familiar with those taps , hopefully the ones I ordered will work ok.

 

[pdentrem]

I see that x-press tap is a company product name. Another piece of info to file away for future use.