"Drill Taps" ?

[wierdscience]

I haven't tried the cheapos yet, but have used the DeWalt brand quite a bit. I use them in a 1/4 cordless impact driver, the trick is not using them on material thicker than the tap is round. In other words 1/4-20 in no more than 1/4 thick material. They work fine in structural steel and also cold rolled sheet like that found in electrical enclosures.

[BCRider]

Yep, good control on breakthrough is essential.

It's not just to avoid driving the tap into the work either. How often in bad positions have we found the drill jumped to the side and wallowed out the hole a little? I know I have. And it's one thing where the flute edges can cut easily into the material. It would be another if we did that and the tap portion dug in. I'm thinking pretty good guarantee of a snapped drap!

[oxford]

and also cold rolled sheet like that found in electrical enclosures.

I’m not positive but I think these may have been originally marketed for electricians.

[wierdscience]

I’m not positive but I think these may have been originally marketed for electricians.

Quite possibly, the first job I used them on was installing about a hundred conduit clips in a metal building.

[macona]

I used to use these on thinner sheet metal and they worked great. Drill speed is fine for tapping, I tap with hand drills all the time.

[gellfex]

the trick is not using them on material thicker than the tap is round. In other words 1/4-20 in no more than 1/4 thick material.

This. I've used the ones with a standard tap shank quite a bit for #10 or less in 1/8 & 3/32 aluminum, 1/4-20 not so much. You just need to be careful, I've snapped my share, and setting a stop on the press helps. But it can be a huge timesaver when you have a few hundred holes to drill & tap. I use my Hamilton sensitive reversing drill press which is really the perfect tool for them, as it stops instantly when you take off pressure, allowing you to shift your mind from drilling to tapping.

[Tundra Twin Track]

This. I've used the ones with a standard tap shank quite a bit for #10 or less in 1/8 & 3/32 aluminum, 1/4-20 not so much. You just need to be careful, I've snapped my share, and setting a stop on the press helps. But it can be a huge timesaver when you have a few hundred holes to drill & tap. I use my Hamilton sensitive reversing drill press which is really the perfect tool for them, as it stops instantly when you take off pressure, allowing you to shift your mind from drilling to tapping.

Could you post a Pic of that Hamilton again,I never get sick of Admiring It!

[gellfex]

Could you post a Pic of that Hamilton again,I never get sick of Admiring It!

Sure, I guess we all have our needs, if you look closely you'll probably see a couple of drill-taps on the stand...



Funny, the sander next to it was a mess that day from my son grinding moose antlers on it to make his pipes!

[Randy]

Where I worked we used them to do a four-hole pattern in aluminum about 1/8" thick. I think we used a multispindle machine and did them in one shot. Not my project so I don't remember the details. But they worked quite well. Well enough that one of our engineers wanted us to try it in solid stock. It was remarkably difficult to explain why it wouldn't work. "Did you try it?" "No. It won't work." "Well, just try it!" Sheesh.

[projectnut]

We used a number of them in a machine rebuilding shop. In our case they were used in a Jet JDP VS125-3 drill press. This particular drill press had a 2-speed motor, depth stops, and auto reverse. The operator set the drill and tap speed and depth stops. The first depth stop determined the depth of the drilled hole while the second determined the depth of the tapped section. When setup properly the machine would drill to the first stop at high speed then shift to the lower speed to tap. When it reached the second depth stop it would reverse.

I bought the machine in 1999 when the shop closed. Unfortunately, I didn't know is that before the shop was closed, they were having problems with the controls, and someone had attempted to "fix" them. The end result was that some components were missing. I attempted to contact Jet on several occasions to find the missing parts. I finally gave up and just use the machine as a standard drill press. I still have all the controls in a box hoping that there will come a time when I find what I need to return it to its original state.

Here's a picture of a similar machine:

[mickeyf]

my son grinding moose antlers on it

Years ago, I sliced up antlers to make buttons for the handwoven clothing my wife and I made. I hope he was wearing a respirator - that stuff is supposed to be very bad for you.

[I make chips]

They're a decent production tool on aluminum with a limited thickness not much more than the screw diameter.

[gellfex]

Where I worked we used them to do a four-hole pattern in aluminum about 1/8" thick. I think we used a multispindle machine and did them in one shot. Not my project so I don't remember the details. But they worked quite well. Well enough that one of our engineers wanted us to try it in solid stock. It was remarkably difficult to explain why it wouldn't work. "Did you try it?" "No. It won't work." "Well, just try it!" Sheesh.

It's remarkable how many degreed 'engineers' have no actual sense of this stuff at all.

[Fasturn]

Never used it on a drill press or manual mill. 20 years back I had to tap a bunch of brackets made from aluminum. Made my own out of a 1/4-20 tap. Used a Tree 325 cnc mill to peck drill, then a tap cycle. No tool changer, so it same alot of time. Guess in a BP mill, you could coast the tap thru using the switch?

For rough work, they can be a great way to save time.
No chamfers !! Was tooling for assembly so no big deal. Did raise some eyebrows . 50 years of machining and only used it once ??

[psomero]

Only ever seen them in a used but unbroken state in a big pile of miscellaneous drills and taps my dad, a former electrician, gave me upon his retirement. He had some good ones, presumably greenlee if they make them because he didn't mess around with crap tools. IIRC, he said he rarely used them but they were good for putting threaded holes into thin stuff like enclosures and junction boxes.

The other places I have seen them is when unaware and naive engineers see and buy them on amazon along with all the other garbage like butter soft taps, drills that don't cut, and crap allen wrenches. I'm the guy that takes that **** and puts it in the ****can as soon as I arrive, because all it's good for is generating scrap and embarrassing rubbish...

Folks who buy the crap draps also buy six or eight flute countersinks, naturally with no relief behind the "cutting edges", and then wonder why they get a deafening squeal and polygonal holes in aluminum. The last two companies I had to go buy a set of single fluted Keo's in the first week because I was tired of getting a headache from that literal noise.