Tap Size Assistance

[azbobver]

I’m in need of advice. I have a hole that uses a 3/8 16 bolt thread (holes are for the Teraflex Split Spoke protection rings). I inadvertently damaged the first 1-2 threads. Can I use a tapered tap size 3/8 16 to clean the threads? Or do I need a different tap size? Or is there another way to clean the threads?

thanks

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[Glamisfan]

I would try that tap, if it can go deep enough to clean up the threads then you will be good. But, you might have to get a bottom out tap for it since it’s probably a shallow hole. A bottom out tap is simply a tap that doesn’t have the taper to it.

 

[azbobver]

I would try that tap, if it can go deep enough to clean up the threads then you will be good. But, you might have to get a bottom out tap for it since it’s probably a shallow hole. A bottom out tap is simply a tap that doesn’t have the taper to it.

Can I use a tapered 3/8 16 cutting screw?

 

[Glamisfan]

Do you have a picture of the cutting screw?

But, thinking about it, a screw would be hard to keep straight. A tap helps you keep it straight.

I believe they also sell a thread cutting file, which might be all you need?

 

[azbobver]

.

Do you have a picture of the cutting screw?

But, thinking about it, a screw would be hard to keep straight. A tap helps you keep it straight.

I believe they also sell a thread cutting file, which might be all you need?

I think I’m going to try this. The hole is about 1 inch deep. So it might work if the end of the bit isn’t too long. I’ll do it by hand.

 

[Glamisfan]

I would be afraid that that type of a tap won’t want to go in straight. I personally would use a regular tap. Also, if you’re not able to find a bottom out tap, buy a regular tap and try that and if you need to you can grind, probably a quarter inch off the end of the tap to make it more of a bottom out tap. But, if the hole is 1 inch deep and it’s only the first couple of threads a regular tap should do the trick.

 

[azbobver]

I would be afraid that that type of a tap won’t want to go in straight. I personally would use a regular tap. Also, if you’re not able to find a bottom out tap, buy a regular tap and try that and if you need to you can grind, probably a quarter inch off the end of the tap to make it more of a bottom out tap. But, if the hole is 1 inch deep and it’s only the first couple of threads a regular tap should do the trick.

Thanks

 

[Duece McCracken]

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I think I’m going to try this. The hole is about 1 inch deep. So it might work if the end of the bit isn’t too long. I’ll do it by hand.

No.

Dont go this route.

As stated above, go NPT or a plug tap.


Manually. Slow and accurate. A power tool drill tap is meant for a fresh hole. Not doing a thread chase.

You want a little lube, and a true hand. It'll come out fine.

I'm not a machinist, but I tap a lot of aluminum and 316 stainless. 3/8-16, 1/2-13, and 1/4-20. That whole mad scientist's industrial electrician gig, lol

 

[azbobver]

I would be afraid that that type of a tap won’t want to go in straight. I personally would use a regular tap. Also, if you’re not able to find a bottom out tap, buy a regular tap and try that and if you need to you can grind, probably a quarter inch off the end of the tap to make it more of a bottom out tap. But, if the hole is 1 inch deep and it’s only the first couple of threads a regular tap should do the trick.

I ordered this…

 

[58Willys]

The bottoming tap you ordered will work…but - what you really need is a thread chasing tap. You don’t want to cut new threads, you just want fix threads you buggered. A thread chaser won’t cut new threads, a tap will. If you use the bottoming tap, make sure you start it in the existing threads, don’t cut new ones. Go slow, use some oil.

 

[azbobver]

The bottoming tap you ordered will work…but - what you really need is a thread chasing tap. You don’t want to cut new threads, you just want fix threads you buggered. A thread chaser won’t cut new threads, a tap will. If you use the bottoming tap, make sure you start it in the existing threads, don’t cut new ones. Go slow, use some oil.

Thanks - I’ll get a thread chasing tap!

 

[MichaelT333]

I’m in need of advice. I have a hole that uses a 3/8 16 bolt thread (holes are for the Teraflex Split Spoke protection rings). I inadvertently damaged the first 1-2 threads. Can I use a tapered tap size 3/8 16 to clean the threads? Or do I need a different tap size? Or is there another way to clean the threads?

thanks

DO NOT USE THE TAP!!!! I’m guessing the people on here don’t realize how a tap works. It’s not for cleaning up threads. It’s for cutting new threads. There is no way you’re going to get it perfectly lined up to the original cut. You’re going to damage them even more the tool you’re looking for is called a thread chaser.

 

[azbobver]

DO NOT USE THE TAP!!!! I’m guessing the people on here don’t realize how a tap works. It’s not for cleaning up threads. It’s for cutting new threads. There is no way you’re going to get it perfectly lined up to the original cut. You’re going to damage them even more the tool you’re looking for is called a thread chaser.

That was my concern, if I tried a tap - to get it lined up. I’ve ordered a thread chaser kit.

 

[Pareto Offroad]

DO NOT USE THE TAP!!!! I’m guessing the people on here don’t realize how a tap works. It’s not for cleaning up threads. It’s for cutting new threads. There is no way you’re going to get it perfectly lined up to the original cut. You’re going to damage them even more the tool you’re looking for is called a thread chaser.

A tap can work, I used one just a few hours ago to clean up the threads on a 30 year old Land Cruiser I’m working in products for.

It’s not ideal, but absolutely can work. I’d just not give it more than a few pounds of torque.

Thread chasers are preferred.

edit: you can also make your own chaser with a bolt and cutoff wheel or dremel. Just add slots that are angled running perpendicular to the threads. You want the angle to create sharp points that turn into the hole when the bolt is tightened.

Just takes a minute to make and is essentially free.

I add these little slots to all my woodworking counterbore guide pins as it helps clean out glue in holes. Super useful!

 

[MichaelT333]

That was my concern, if I tried a tap - to get it lined up. I’ve ordered a thread chaser kit.

Didn’t you say the bolt was 3/8? That is a metric set. I am not sure if the bolts underneath are metric or standard. Maybe someone here will know

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