Thanks Russell very helpful.

Thanks too Russell….Now cause of you I feel like I’m from an inefficient dinosaur area with my screw gun, oil dip & tooth brush removing shaving after EACH tap :o
No wonder it took me 25+ minutes to tap what…. 30 holes !!
Progress + man and his toys = efficient, fun work :D
Seriously, thanks for this & the links.
BTW ( Half dinosaur, my screw gun has the impact option witch I did use !!!)
Amicalement, Robert ;)

Russell,

Great video. I learned something :)

Thanks,
Greg

Thanks, very instructive and good production value.

Joe

Maybe we do have to sound some caution here . . . . . . If we push the limits, we do increase the chances of breaking the tap. And it is no fun to remove a broken tap - sometimes (most times?) you won't get it out.

Maybe this is a good time to start discussing on the methods of removing a broken tap . . . .

Yes, I would like to know how to remove a broken tap. :( I had a crappy one I broke once and was able to drill it out. Believe it or not. :)

Here is a nice article from the web:

http://www.metalartspress.com/PDFs/R..._Fasteners.pdf

Thanks guys for the comments.

Gerald is right though, Caution does need to take place. Although this method is extremely easy it just makes it that much easier and faster for you to screw up.

Industrial environments use a similar method but they are called tapping arms and go for thousands. One day I will build one but for now I just use my hand. You can see what I am talking about over at the CNCcookbook Bob just did a article on my video which explains some of the problems and solutions to my video.

Here is a video of some tapping arms. http://www.youtube.com/watch?v=FZLU-...eature=related

Flex arm
 

We have one of the flex arms it works great .

Pilot hole size is vital to make a good tap hole. Hole too small the tap will become hard to turn or even break frequently, too large the there will be too little thread left.

I hope this table will be helpful

M3 x 0.5 Hole dia. 2.5
M4 x 0.7 Hole dia. 3.3
M5 x 0.8 Hole dia. 4.2
M6 x 1.0 Hole dia. 5.0
M8 x 1.25 Hole dia. 6.8
M10 Hole dia. 8.5
M12 Hole Dia. 10.2

small variant from it is ok.

With standard metric threads, the hole size is simply the diameter minus the pitch. No need for a table like above. :)

left hand drill bits could be use ,sometime it is all you need if you are lucky:)

www.nastyz28.com/forum/showthread.php?t=107063

Another valueble lesson learnt. :D

...another reason to love the metric system.

Russell I took your recommendations and bought the stuff you suggested ..... can't believe how good it works. I tapped about a dozen 1/4" holes just for fun ...... man it's fast. Thanks J.R.

J.R.

Im glad it worked out for you. I cannot tell how many non-believing emails I got from that Youtube video. As long as it helped out one person. Let me know if you want my plans for the tapping arm.

JR,
Was the stuff expensive? And do you have more info on what you got like part numbers and such?

Heath I bought the tap adapters like the ones you and Russell pointed me to, and the 3/8 butterfly impact wrench Russell showed me at Harbor freight. Everything cost about $45.00 us. I'll save that much in less aggravation in one day :D

JR,
Thanks. Did you have to throttle that butterfly adapter down for the threading at all or just run it at full pressure? I was worried about breaking a tap. :)

When you put the tap in contact with metal, you give it full throttle @ 80 psi and it immediately starts in the impact mode ..... it's a beautiful thing to see it tap. It will tap 1/4 20 tpi in .25" mild steel in 3 seconds flat........ that's smoking :). With the taps below you can also debur at the same time. I made an adapter so I could use these with the impact wrench. Oh one last thing, I don't use these to drill the hole.

http://www.harborfreight.com/cpi/cta...emnumber=95529

I experimented with all the method suggested, cordless power drill, the pneumatic wrench, even auto tapping machine. But like Gerald, my favorite goes to hand tap using spiral point bits... After a few slanted tap holes & a broken bit, like cycling, everything just went on without a glitch. The monotonous back & for turning action with timely squeeze of WD40 is calming to the mental health. Also its easy on me ears & no need to dough flying chips. :D

Tap all the holes on the main beam takes less then an hour,,, not too slow in my opinion. Just grap a stool & its really comfortable.;)

Ken, Sorry you didnt enjoy the Pnuematic Wrench. Almost everyone I have shown enjoys tapping that way. I will agree that it gets kinda loud but I just throw on my Ipod and some ear muffs.

Russel,
don't get me wrong, your wrench method is fast. It will be my 1st choice if mass production is involve. Just that I do work late into the night, so hand tap helps to keep complain down :D

PS,
I have a boom box in the shop, I don't like to expose to the danger of loose ear phone wire entangle with anything while working, it can be dangerous at times. Moreover, I feel secure when I can hear whatever that is happening around me... Just some of my hard habits...

Okay Ken, I think we have another misunderstanding; My favourite is NOT handtapping. (I go cordless drill just because they are normally lying around)

Ooops, another blunder, sorry Gerald.

Depending on the thread pitch I do this operation before tapping.

Is it an idea to pass the tapping head through a block of wood to help keep it vertical?

That can work.

I have seen that done before. Here are some cool ideas.

http://www.rockler.com/blog/index.cf...E0FA7D26277FE0

if you have a standard tap start with that and finish with a bottoming tap. to keep it straight by hand is just practice. it isn't to hard if you take it slow.