How to Power Tap

[TomG]

Here's an unconventional tapping technique that you won't learn in any machine shop class or find in any text. Power tapping is hated by the purists, but loved by me because it's a quick and easy way to tap a hole.

Tom

[f350ca]

Good one Tom. I guess I do it ununconventionaly or Im very lucky but seem to get away with using hand taps. BUT I can see from your video the spiral point cuts far easier. I have a good supply of hand taps that were given to me but if I ever need to buy one it will certainly be spiral pointed.

[PixMan]

You do a nice job with video and the audio is good too. I only have a little Canon point & shoot that can do low-resolution video, so my audio sucks. I also don't plan videos well, so here's an example of me power tapping some 1144 steel (I stated 1117 in the video for some reason), and you're going to nail me for wearing the watch that's rarely off my wrist. ;)





I also didn't have any editing software until Russ told me about MovieMaker, which I've yet to use.

[TomG]

Looks good to me Ken, there is a lot that goes into making a video. If it was easy, anyone could do it.

Guess I better get busy on the safety video I've been thinking about to show what happens when a loose piece of clothing or jewelry gets caught on a rotating tool.

Tom

[PixMan]

I do remain aware of where my hand and my watch is at all times.

[stevec]

I love those spiral point or "gun" taps, I think the "gun" name derives from the fact that they "shoot" the cuttings forward in front of the tap.

They (we all know who "they" are, right?) claim that the spiral point taps should only be used for "through" holes but I find, if I can tap drill much deeper than I need to tap they'll work OK.

As far as tightening the chuck light enough to allow the tap to slip, I shy away from that because of the potential for damage to the chuck jaws.

I've even gound 3 flats on one of my ¼-20 gun taps.
   

I often "power start" a tap in the drill press. after drilling I chuck the tap, turn the drill press on, lower the quill to just about entering the whole, then turn off the drill press as I enter the tap into the whole.
Then I release the tap from the chuck and finish the tapping by hand, the idea being to get a good straight start on tapping the hole.

[TomG]

Steve,

I added a note in the video about starting a tap in the mill and then finishing by hand. I do that a lot with small taps in blind holes. I also find that I don't need as a deep a hole if I back the tap out a few times and clear the chips out of the hole. Allowing the tap to slip in the chuck is a must to get to the bottom of a blind hole.

Chuck wear is a common complaint regarding this technique, but it just doesn't happen. That chuck on my mill was purchased with the mill in the 80's and I power tap with it all the time. It is just as concentric today as when I bought it.

Tom

[oldgoaly]

so basically by hand tightening the chuck is taking the place of a tap driver attachment.
Tom, now you show the battery drill trick! we tapped a bunch of 1/2 fine threads on the power hammer, but I have 4 flute taps But when we add to the column a planishing hammer, English whee, another power head, gonna invest in a spiral point tap!
Ken, For a long time I always wore my watch and wedding ring then there was a rash of guys getting electrocuted so I stopped wearing them both. So what time is it anyway?

[stevec]

Tom, maybe I should have said "fear" as opposed to potential. I've noticed some of my taps with faintly etched info on the shank no longer have the info due to slippage in the chuck.
I know I should be able to identify taps by looking at their size & pitch but I have metric taps that sometimes migrate into the imperial tap drawer and I like to make sure I'm taping what I want.

[PixMan]

When I was running a radial drill years ago (1982-1987) I tapped a LOT of blind holes under power. I got very good at it because I'd wrap some masking tape around the tap at the depth I needed to go and never broke a tap! I used spiral point taps and simply dug the chips out after it was done. They were mostly 1/2-13, 5/8-11 and 3/4-10 threads, so very sturdy taps.