Looking for 1/2" x 17tpi bolts.
- Thread starter izthebye
- Start date
captainmike
CGN Regular
- Location
- GVA- fraser valley BC
Are you sure it is not metric like 12x 1.5
Mike
Mike
Blastattack
CGN Ultra frequent flyer
- Location
- Winnipeg MB
Apparently they are 1/2-27. You will not find a substitute.
My thread pitch gauge fits exactly on 17 tpi. I'm reluctant to mess with metric for fear of literally screwing up the casting in the Star. I have found out that some professional microphone stands use a 17 tpi thread. Now I just have to locate one. Thanks for the suggestion!
If you're going to make a bullet punch it sort of implies that you have a lathe. Otherwise how would you turn the shapes for the punches?
Does it do threading? If so cut your own threads. Never single point cut a thread on your lathe? Sounds like a good time to learn how!
Using one of your existing punches or fittings with a male thread check for size using the three wire method and use that as your sizing guide for cutting the thread on your lathe.
Does it do threading? If so cut your own threads. Never single point cut a thread on your lathe? Sounds like a good time to learn how!
Using one of your existing punches or fittings with a male thread check for size using the three wire method and use that as your sizing guide for cutting the thread on your lathe.
regarding measurement of threads, if you have a part that fits already use the digital caliper and measure across the root of the threads with the end of the jaws, zero it and cut till its zero, yes 3 wire works best but we are not talking precision threads, angle is 60 degrees regardless of metric or Unified so the caliper will be close to bang on
just checked my lathe and 17tpi is not a option so without changing the gear ratio cut to 1.5mm pitch
just checked my lathe and 17tpi is not a option so without changing the gear ratio cut to 1.5mm pitch
Hmmm.... my lathe doesn't have a 17 tpi either. So it looks like 1.5mm pitch and a run with around a max of 5 or 6 turns worth of thread so the slight error doesn't bind is going to be the way to go.
Laurencen, I first thought "THAT WON'T WORK! " with your caliper to the thread root idea. But on second thought the width of the faces of the calipers even in the knife blade areas will ride on the slopes of the threads slightly up off the roots and sort of act like the wires. I'll have to remember that and try it next time. Plus it gives me an idea for modifying a set of outside arm style calipers to use for measuring internal threads! So thanks for THAT ! ! ! !
Part of why I suggested the three wire idea is that he won't be able to take the threading out of the chuck to try it on the lubrisizer. And I sort of doubt that the lubrisizer is small enough to spin onto the thread being cut like a nut to test the fit. So some way of measuring to ensure a match is needed for this case.
Laurencen, I first thought "THAT WON'T WORK! " with your caliper to the thread root idea. But on second thought the width of the faces of the calipers even in the knife blade areas will ride on the slopes of the threads slightly up off the roots and sort of act like the wires. I'll have to remember that and try it next time. Plus it gives me an idea for modifying a set of outside arm style calipers to use for measuring internal threads! So thanks for THAT ! ! ! !
Part of why I suggested the three wire idea is that he won't be able to take the threading out of the chuck to try it on the lubrisizer. And I sort of doubt that the lubrisizer is small enough to spin onto the thread being cut like a nut to test the fit. So some way of measuring to ensure a match is needed for this case.
caution modifying the ends of a caliper, its best if the caliper touches sort of half way down the V and unless you are using a tool grinder or surface grinder the chances of having a taper across the jaw will result in different readings, another way is take a number drill that will enter the V and use a micrometer over the diameter and drill as one does with the 3 wire method, at 60 degrees you can even figure the actual root but way too complicated just use the digital caliper.
we have 4 lathes here at work and neither has 17tpi listed, OP, what is the actual outside diameter you measure?
I'm really starting to think that this thing is a 12mm-1.5mm pitch as well. The thread sizes for taps at Enco doesn't list any 1/2-17. They have 1/2-16 and 1/2-18 with nothing in between.
And yes, your 17 tpi thread gauge is EXTREMELY close to the 1.5mm pitch so it will look like it fits. But I'd bet that if you check the OD of the thread on one of the dies you have already you'll find it's enough under 1/2 inch that it's more likely to be metric threading.
Simple enough to test. Take one of your dies around to a place with bulk fasteners and try it in a 12mm 1.5 pitch nut.
And yes, your 17 tpi thread gauge is EXTREMELY close to the 1.5mm pitch so it will look like it fits. But I'd bet that if you check the OD of the thread on one of the dies you have already you'll find it's enough under 1/2 inch that it's more likely to be metric threading.
Simple enough to test. Take one of your dies around to a place with bulk fasteners and try it in a 12mm 1.5 pitch nut.
Blastattack, you are correct. It is 1/2" x 27. New bifocals are on order.............and the search continues......
BCRider, I do indeed have a lathe. However, due it's country of manufacture, I don't think it is quite up to snuff at the moment. It needs a complete teardown and blue-printing! The operator is beyond help as far as threading goes! And it is 1/2" x 27 tpi. As I mentioned to Blastattack, new bifocals are on order! Learning to thread would be a good dedicated project. Thanks for your kind advice.
Hugh
1/2" 27tpi dies are available (and cheap) from amazoom and fleabay.
Fair enough. And when you decide to have a go check out You Tube. It's got oodles of instructional videos on single point threading.
In the meantime if you end up threading your own 1/2 inch stock with a die check out a google search for "tail stock die holder". It's a great accessory you can make pretty easily on your lathe which give you "accurate enough" axial threading for most requirements. Here's a picture of the one I made in action.
It slips on with a nice sliding fit over a stub of 1/2 inch rod held in the tail stock chuck so it can slide back and forth and be turned. This pilot shaft provides "good enough" centering for most needs and would be handy for your situation where you'll turn then thread or thread then turn these sizing dies you're after.
Fair enough. And when you decide to have a go check out You Tube. It's got oodles of instructional videos on single point threading.
In the meantime if you end up threading your own 1/2 inch stock with a die check out a google search for "tail stock die holder". It's a great accessory you can make pretty easily on your lathe which give you "accurate enough" axial threading for most requirements. Here's a picture of the one I made in action.
It slips on with a nice sliding fit over a stub of 1/2 inch rod held in the tail stock chuck so it can slide back and forth and be turned. This pilot shaft provides "good enough" centering for most needs and would be handy for your situation where you'll turn then thread or thread then turn these sizing dies you're after.
Thanks BCrider et al! I have a 1/2" x 27tpi die on the way from the People's Republic courtesy of Amazon. In the meantime, I'll check out your "tail stock die holder".
Hugh
