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Since Lathesmith has retired, the source for jamb nuts with set screws has dried up. Is anyone here making their own? I tried a number of times at tapping the 8-32 thread with the standard pointed tap on my drill press. By the time I get "some" threads cut, there's not enough threads to hold a set screw to lock the nut on a Star punch. The tapered end of a bottom tap is much shorter but I don't have one. Is there anyone who would want to share their process?
I've made bottoming taps by grinding the point off a standard taper tap, not the best but it works.
modifying a staring tap is more than just grinding the point off. A starting tap has 7-8 threads tapered to start and cut smoothly, A plug tap is 4-5 tapered threads to get closer to the bottom. a bottom tap is 2 threads tapered up to cut closest to the bottom of the hole.
A 8-32 tap set is around 10-15 dollars for all 3 style taps. Ordering a the 8-32 tap is 5-6 dollars. While taps are considered consumables a properly used and cared for tap will cut a lot of threads. This includes using the correct tap drill.
Using a bottom tap from the start will be very tough as the chip load is very heavy on the short taper. While going in with a starting or plug may not give full threads it removes and eases the chip load on the bottom tap.
Order a tap set from Mc Master Carr, Grainger, or other tool supplier. Some cutting oil/fluid.
Disassemble the nut from the part and your tapping a thru hole instead of a blind hole. Apply the cutting fluid then start the tap into the hole. rotate and break chip until to depth if needed finish with the bottom tap.
I am making these. Pm me
https://castboolits.gunloads.com/sea...rchid=10543760Quote:
Originally Posted by ammohead
Didn’t your tap just go into the space in the center of the nut? A normal tap should work fine since it isn’t a blind hole you are tapping.
I changed my process since I started this thread. I was using my big drill press. There's way too much spring tension to let the chuck retract without tearing out the threads I just made. I drilled the hole, then removed the belt off the pulleys and turned the chuck by hand to make the threads (or turned the pulley by hand). I then released the tap from the chuck and screwed it out of the nut by hand with a tap wrench. I ended up with 9 perfect jamb nuts with set screws out of the 10 I purchased. Now I see Ammohead is making these nuts with set screws. I'll be giving him some size die business now though.
On that small and short a thread, a cordless drill with the tap chucked does a great job. Hit the reverse switch and the tap will back right out. About 10 seconds to tap each hole.