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Hardinge TT Tapping Head

majohnson

Cast Iron
Joined
Jan 3, 2013
Location
Erie, CO
I pick up a TT tapping head, and have been looking around for some instructions and can not find much. I figured I would read up on it before trying the thing out. Anyone have info on setting these things up.
 
TT holders are great! They're basically the internal thread equivalent to acorn die holders, but nicer to use.

There are really only two things to set up on the holder itself. You need the correct TT collet for the tap size you're going to use, and you need to make sure the TT holder is set for right-handed or left-handed to match the tap. There is a pawl and a spring visible in the front, black part of the holder in the lower left of the attached photo. The pawl needs to be flipped to the R or L side (stamped on the body) and the spring needs to be moved to the same side so it forces the pawl outward.

Assuming you're using the TT holder on a small turret lathe (like the Hardinge DSM-59), you want the spindle turning in the proper direction for the tap to cut, advance the turret until the tap starts cutting, then continue with very slight feed pressure until you reach the desired tap depth. Then stop advancing the turret. The tap will continue to feed a little further, disengaging the dogs that lock the two parts of the holder and allowing the front, black part of the holder to spin with the spindle. Reverse the spindle. On the DSM-59 do not be shy about plugging directly from forward to reverse. The pawl will immediately lock up the holder and the tap will start unscrewing itself from the work. Retract the turret with slight feed pressure.
 

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I have several TT holders and a bunch of TT collets. One problem I have seen when I got a used TT holder is that the 1/8" dowel pin that keeps the collet from spinning in the holder is sometimes pushed back in its hole, preventing it from functioning. It is possible to take the holder apart and drive the pin back to its proper position. When installing a collet, the slot in the collet back has to engage the pin. If the collet is placed in the holder incorrectly and the nut is then tightened, the pin is pushed back in its hole.

Larry
 
When I remove the nut from the collect side, I do see the pin sticking up. To check the dog do I remove the allen bolt to get it to separate?

Mark
 
I'm not near the shop right now, but if I recall correctly, the two main parts are bolted together through the hollow shank. Undo that bolt and it comes apart.

BTW, see the three raised dogs on the face perimeter of the black part, and one corresponding dog down inside the steel-colored part on the other side of the spring? The height of those dogs is how far the tap will continue to feed once you stop advancing the holder. Alternatively, that's the "window" of tolerance you have to match the tap self-feeding action with the turret feed.
 
That’s correct! Remove the long Allen head cap screw from the back and it comes apart, including three springs and some bearing balls. They are easy to clean and device.


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I bought a used TT holder. It's missing the spring that goes inside, as seen in the photo above. Anyone have dimensions? I just as soon buy a stock spring from McMaster.
 
If I recall correctly, they’re not very expensive from Hardinge. Buy all three while you’re at it!


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Apparently Hardinge no longer sells parts directly, but rather through other companies. I don't recall who handles parts and support for Illinois. I'm in Michigan and dealt with Gosiger, and they were good and helpful, but it's been a few years. That said, Hardinge should at least respond to your inquiry with the appropriate contact information.
Gosiger | Serious Solutions
 
This is the information I provided Gosiger and it worked.
For hardinge TT tapping heads I need the following parts, which comes down to all 3 springs in each head X 4. I think I have provided good part numbers, but cannot be sure. They were numbers found on bags containing the right parts, but I do not have a Hardinge parts list for these tools.

#6 0009859 Small spring to go behind pawl apx. .6” long X .12” OD

# ST 8872 Large diameter spring to provide float apx. .5” long X .86” OD

# ST 8101 Spring that goes into the shank. Bolt passes through it. apx. 1.5" long X .365 OD

And the email that worked for me in December of 2016;
[email protected]
 
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Within the last year I've bought several parts direct from Hardinge Elmira. If you can figure out the part no, their site will show prices and availability. I've always called to order and their phone service was excellent. My understanding is that they've recently brought most of their parts service back in-house.
 
Get a Hardinge TT or something else?

I'd like to get a tapping head. My "go to" size is 1/4" - 20 t.p.i. but I own a very large range of taps. The idea of the torque bar on some designs doesn't appeal to me. The Hardinge tapping head has no bar to wack me in the face when I'm trying to get close enough to see. Does it self reverse or what does it do when it hits bottom of the hole? Ar there other tapping heads that I should look at?

Thanks in advance.
 
I'd like to get a tapping head. My "go to" size is 1/4" - 20 t.p.i. but I own a very large range of taps. The idea of the torque bar on some designs doesn't appeal to me. The Hardinge tapping head has no bar to wack me in the face when I'm trying to get close enough to see. Does it self reverse or what does it do when it hits bottom of the hole? Ar there other tapping heads that I should look at?

Thanks in advance.

The Hardinge TT releasing tap holder is designed to mount in a lathe turret. The rotating workpiece is in the lathe spindle and has to stop and then reverse to back the tap out of the hole.

If you want a reversing tapping head for use in a mill or drill, look at Tapmatic model 50X and similar models. They have to have a torque arm in order to reverse.

Larry
 
That cuts right to the chase; thank you. Is there any meaningful difference between Procunier, Tapmatic, Enco or others?
 
I regularly use the larger enco. It will do hundreds of thousands of holes- but taps bigger that 1/4" are hard on it, as are dull taps. The reversing gears wear out. Also have the equivalent tapmatic, but with a different shank- it sees less use but seems higher quality and smoother operating.
 
I have only used the older Procunier heads and have been pleasantly surprised at how well the internal friction clutch cone holds up. I do not frequently use a head to tap larger than 3/8" and very rarely 1/2", so can't say how they work for larger taps. I did a job involving 106 1/4-20STI tapped holes in aluminum plate, each part, and it was a breeze with a Procunier head on a drill press. Tapping by hand would have been agony, and the job certainly didn't warrant buying a machine with rigid tapping.
 
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The Procunier and Ettco units are smooth and controllable compared to the 'snappy' and sometimes jerky action of the Tapmatics.


I have only used the older Procunier heads and have been pleasantly surprised at how well the internal friction clutch cone holds up. I do not frequently use a head to tap larger than 3/8" and very rarely 1/2", so can't say how they work for larger taps. I did a job involving 106 1/4-20SPI tapped holes in aluminum plate, each part, and it was a breeze with a Procunier head on a drill press. Tapping by hand would have been agony, and the job certainly didn't warrant buying a machine with rigid tapping.
 








 
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