Power tapping - what do you use to hold the tap?

[npalen]

This thread is a bit stale but don't see any mold growing so will post this video:

https://www.youtube.com/watch?v=9E2Sbra8t3I

I just happened to run across it and brought back memories of this thread that presented some ideas similar to that in the video. I thought the method of making the thread depth readout was interesting and very functional. The handle for locking the spring loaded tap/die holder seems to be well executed.

[Tundra Twin Track]

Not trying to argue about this, just trying to learn something.

Why are you concerned about the strength of retention? It seems to me that while driving the tap in you would be applying some, at least moderate amount of pressure so the tap would always be pressed into the holder. That is how a Tapmatic is used. And when backing out that process itself would provide that pressure. Or would it? It would seem that the O-ring would only come into play when the tap is not actually being used. So, as a serious question, what am I missing?

I am very interested in this topic and have just received delivery of a length of 3/4" precision shaft that I am going to convert into tap holders. I am thinking about O-rings for tap retention but want to know if that is a bad idea. And/or what ideas would be better. These tap holders will be just step one in making a tapping device for my lathe and/or drill press or mill.

It may work okay on a lathe depending if your dragging the tailstock,the tap may pull out.Using it on a Mill or Drill Press with the pull of the quill spring may also do the same.Never used a Tapmatic,I thought they used a rubber-steel collet for retention.

[Paul Alciatore]

Not trying to argue about this, just trying to learn something.

Why are you concerned about the strength of retention? It seems to me that while driving the tap in you would be applying some, at least moderate amount of pressure so the tap would always be pressed into the holder. That is how a Tapmatic is used. And when backing out that process itself would provide that pressure. Or would it? It would seem that the O-ring would only come into play when the tap is not actually being used. So, as a serious question, what am I missing?

I am very interested in this topic and have just received delivery of a length of 3/4" precision shaft that I am going to convert into tap holders. I am thinking about O-rings for tap retention but want to know if that is a bad idea. And/or what ideas would be better. These tap holders will be just step one in making a tapping device for my lathe and/or drill press or mill.

I’ve used them a lot with extensions but they would not be my choice for power tapping,not enough retention with O ring.

[Tundra Twin Track]

Hey now, I have a set, not as old but still made in USA. I bought the set for a job on a car that was coming up, difficult to get a "T" handle tap wrench into. I had to pre-order it to account for the shipping delay (no amazon that day). I guess the shipping time took too long and I found a workaround, never got to use them. Maybe next time JR

I’ve used them a lot with extensions but they would not be my choice for power tapping,not enough retention with O ring.

[mikey553]

I don't have a collet chuck for the lathe, just the 5" 3-jaw and a 6" 4-jaw. Does a collet chuck typically grip tighter than a jaw chuck assuming the part being held is in the correct range of the collet.

I really don't know about a collet chuck. I have a 5C chuck for my lathe, but never tried it for tapping. It may or may not hold the part tight enough, but at at least it should not damage the part.

[JRouche]

If you want individual holder for each size tap ,these aren’t free but close at that price.They have O ring for retention,have had a set for 30 yrs.

Hey now, I have a set, not as old but still made in USA. I bought the set for a job on a car that was coming up, difficult to get a "T" handle tap wrench into. I had to pre-order it to account for the shipping delay (no amazon that day). I guess the shipping time took too long and I found a workaround, never got to use them. Maybe next time JR

[The Metal Butcher]

Regarding power tapping in the lathe, I'm wondering what you guys do to prevent the workpiece slipping in the chuck when tapping with, say 1/2"-13 and larger, taps. I can usually hold the tap ok in a self-tightening jacobs in the tailstock but the workpiece generally will start slipping in the chuck. I have, on occasion, machined three flats on the workpiece but that is not usually practical. I guess a spot of weld would works also but......

4 Jaw.

Old Russian guy at work was tying to tap 1-5 LH ACME 2" deep through bronze. We had a new 10" Bison 3 jaw, cranked down to the point the handle bent. It wouldn't do it. Just slipped and machined the bronze with the jaws. I told him we had to put the 4 jaw on, and sure enough sailed right through.

Now, how in the world the 10" Chinese adjustable wrench driving it didn't explode is beyond me. Well north of 200 fl-lbs I'd say.

[Paul Alciatore]

12” 3 jaw, yea, that'll work. But it's gonna be a tricky design for a back plate for that on my SB-9.

Any ideas you would care to share? 😏

I think I still have that algebra pencil that some kind, upper classman sold me back in my freshman year in high school. Perhaps that'll help. Now, where did I put that thing? 🔍🔍🔍

No issues so far holding workpiece in 12” 3 jaw threading 7/8”-9,4 jaw scroll Chuck for holding tap.

[Tundra Twin Track]

Regarding power tapping in the lathe, I'm wondering what you guys do to prevent the workpiece slipping in the chuck when tapping with, say 1/2"-13 and larger, taps. I can usually hold the tap ok in a self-tightening jacobs in the tailstock but the workpiece generally will start slipping in the chuck. I have, on occasion, machined three flats on the workpiece but that is not usually practical. I guess a spot of weld would works also but......

No issues so far holding workpiece in 12” 3 jaw threading 7/8”-9,4 jaw scroll Chuck for holding tap.

[npalen]

I don't have a collet chuck for the lathe, just the 5" 3-jaw and a 6" 4-jaw. Does a collet chuck typically grip tighter than a jaw chuck assuming the part being held is in the correct range of the collet.

[mikey553]

Regarding power tapping in the lathe, I'm wondering what you guys do to prevent the workpiece slipping in the chuck when tapping with, say 1/2"-13 and larger, taps. I can usually hold the tap ok in a self-tightening jacobs in the tailstock but the workpiece generally will start slipping in the chuck. I have, on occasion, machined three flats on the workpiece but that is not usually practical. I guess a spot of weld would works also but......

My situation is exactly the opposite - tap slips but not the work. My drill chuck on the lathe is not the best and I am working to improve that.

How do you hold the workpiece? Most often I use a 6" 3 jaw chuck and it has plenty of power to hold the bar, which is bigger than the tap size. I did not try to hold a finished part during tapping. In such case I cannot hold it too tight in the chuck or it will damage the part. Did you try to use a collet chuck to hold the part for tapping?

[npalen]

Regarding power tapping in the lathe, I'm wondering what you guys do to prevent the workpiece slipping in the chuck when tapping with, say 1/2"-13 and larger, taps. I can usually hold the tap ok in a self-tightening jacobs in the tailstock but the workpiece generally will start slipping in the chuck. I have, on occasion, machined three flats on the workpiece but that is not usually practical. I guess a spot of weld would works also but......

[Paul Alciatore]

OK, seems that when you look specifically for that, they are available from more than one place:

https://www.amazon.com/dp/B0BTP297Z8/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B0BTP297Z8&pd_rd_w=D5Fs4&content-id=amzn1.sym.d81b167d-1f9e-48b6-87d8-8aa5e473ea8c&pf_rd_p=d81b167d-1f9e-48b6-87d8-8aa5e473ea8c&pf_rd_r=ZT2JE447G9WCPD8P3Q49&pd_rd_wg=Sy6ni&pd_rd_r=1071291e-6f06-4a29-b0b8-5f51fda7f084&s=hi&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUk5EUDZXQ0hQN1BKJmVuY3J5cHRlZElkPUEwODE4MzYzMjVBMTkwSkdNQjlLQSZlbmNyeXB0ZWRBZElkPUEwNjQzODYwM0c3SUJFMDNXTzk0RSZ3aWRnZXROYW1lPXNwX2RldGFpbF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Not a recommendation. They only fit 3/8" socket drive so not terribly concentric.

You've only got something like this if you want universal. Reviews are somewhat mixed mind.

https://www.amazon.com/Sealey-AK872-2pc-Adjustable-Socket/dp/B084ZMQZJR

Also not sure how big the OD of the back is if you're thinking of putting it in a chuck or collet but you could chuck a 3/8" extension bar. There are ones (listed previously) with a cross-bar for hand use and a 'tail' to be gripped in a chuck. I picked up a set of those from India via eBay and they seem nicely made and well packed....but I haven't actually tapped anything with them yet so I can't recommend them (or otherwise!) just yet.

[Paul Alciatore]

Personal observation only, but as far as I can see, the thread pitch does not seem to come into play in determining the shank and square size.

I find it interesting that, at least one tap manufacturer uses the same shank and square sizes for metric taps as well.

Paul, I don't see any designations of pitch and wondering if it doesn't affect the dimensions listed?

https://www.regalcuttingtools.com/sites/default/files/asset/document/Standard%20Tap%20Size%20and%20Dimensions%20Chart%20302.pdf

It seems to have only the coarse thread taps, but does include metric sizes which seem to use the same dimensions as the English sizes.

[/QUOTE]

[Cenedd]

You've only got something like this if you want universal. Reviews are somewhat mixed mind.

https://www.amazon.com/Sealey-AK872-2pc-Adjustable-Socket/dp/B084ZMQZJR

Also not sure how big the OD of the back is if you're thinking of putting it in a chuck or collet but you could chuck a 3/8" extension bar. There are ones (listed previously) with a cross-bar for hand use and a 'tail' to be gripped in a chuck. I picked up a set of those from India via eBay and they seem nicely made and well packed....but I haven't actually tapped anything with them yet so I can't recommend them (or otherwise!) just yet.