Tapping threads into metal - Page 2

Robert M · #31 Sat 07 November 2009, 19:42

Nothing like a simple test

Well, broke my barrier…Did it with my drill / screw gun…

Attachment 6951

Twice taped in C-3 as a test and all went super fine & easy with some treading / tapping oil.
Did this a few time in alu before, but was afraid to even think trying this drill thing in steel….May be I over lubed it, but rather a little more oil than a broken tap !!
Goes to say….give it a try, you may be surprised !!
Thanks again….Later, Robert

Gerald D · #32 Sat 14 November 2009, 06:33

Tapping some test holes is always a good idea.

Because we are tapping into relatively thick metal, you can increase the pilot hole size, which makes the tapping a LOT easier with the power drill. Again, experiment with pilot hole size to see when an over-tightened screw risks stripping out.

Regnar · #33 Sun 15 November 2009, 18:33

I often tapped by hand and by a battery power drill for a long time until I read a tip on CNCcookbook.com

He uses a impact wrench and tap sockets. I also use a tap guide to get it straight in. But I have to say I can tap very quick now and with just one hand. I build a dolly out of 3/8 thick square tube and tapped 16 holes for the casters in under 5 minutes with no breakage. I bought the Butterfly Impact from Harbor Freight for 15.00 the tap sockets from use-enco for 20 and made my own tap guide for a few dollars in scrap aluminum. You will need a air compressor. I use to dread tapping any hole but now I just chuck it up and blast away.

Link to the article http://cnccookbook.com/CCBlogJul2009.htm

Information is about 3/4 down the page.

riesvantwisk · #34 Sun 15 November 2009, 20:55

Quote:

Originally Posted by Regnar

I often tapped by hand and by a battery power drill for a long time until I read a tip on CNCcookbook.com

He uses a impact wrench and tap sockets. I also use a tap guide to get it straight in. But I have to say I can tap very quick now and with just one hand. I build a dolly out of 3/8 thick square tube and tapped 16 holes for the casters in under 5 minutes with no breakage.

Where you in a tapping contexts?? That's a stunning 18Sec per hole!

Thanks for the link...

Personally I look at it from the top, and two side, then slowly I start tapping. Then I rotate, and re-check the sides and repeat this until the top goes through and take my time...

Ries

Gerald D · #35 Sun 15 November 2009, 22:32

18 sec per hole is relatively slow - Russel was not exaggerating when he said under 5 minutes

J.R. Hatcher · #36 Mon 16 November 2009, 05:27

Thanks Russell that info will come in handy. Show us a tap socket??

domino11 · #37 Mon 16 November 2009, 05:59

Here is one JR.
Tap Adapter

J.R. Hatcher · #38 Mon 16 November 2009, 07:02

Thanks Heath

Regnar · #39 Mon 16 November 2009, 14:22

Quote:

18 sec per hole is relatively slow - Russel was not exaggerating when he said under 5 minutes

I guess I should have mentioned I took my time, Insured the tap was straight and clamped down the tap guide.

When I throw caution to the wind I can tap 1/4 1018 steel in 3 seconds and can tap 1.25 inches into 6061 in 15 - 16 seconds

Regnar · #40 Mon 16 November 2009, 15:00

Quote:

Thanks Russell that info will come in handy. Show us a tap socket??

I will do you one better JR. Here is a HD video of me tapping 6 holes. 3 in steel and 3 in aluminum. http://www.youtube.com/watch?v=_XLGCt5UQGM

Here is the links to the items I used.
Socket Adapter.
http://www.use-enco.com/CGI/INLMK32?PARTPG=INSRAR2
Butterfly Impact Wrench
http://www.harborfreight.com/cpi/cta...emnumber=93100

J.R. Hatcher · #41 Mon 16 November 2009, 17:16

Thanks Russell very helpful.

Robert M · #42 Mon 16 November 2009, 18:21

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

No wonder it took me 25+ minutes to tap what…. 30 holes !!
Progress + man and his toys = efficient, fun work

Seriously, thanks for this & the links.
BTW ( Half dinosaur, my screw gun has the impact option witch I did use !!!)
Amicalement, Robert

Greg J · #43 Mon 16 November 2009, 18:28

Russell,

Great video. I learned something

Thanks,
Greg

jehayes · #44 Mon 16 November 2009, 19:41

Thanks, very instructive and good production value.

Joe

Gerald D · #45 Mon 16 November 2009, 22:10

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 . . . .

domino11 · #46 Mon 16 November 2009, 22:14

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.

Gerald D · #47 Mon 16 November 2009, 22:21

Here is a nice article from the web:

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

Regnar · #48 Tue 17 November 2009, 14:34

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

Castone · #49 Wed 18 November 2009, 19:28

We have one of the flex arms it works great .

KenC · #50 Thu 19 November 2009, 22:21

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.

Gerald D · #51 Thu 19 November 2009, 22:37

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

normand blais · #52 Fri 20 November 2009, 06:44

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

KenC · #53 Fri 20 November 2009, 23:18

Quote:

Originally Posted by Gerald D

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

Another valueble lesson learnt.

smreish · #54 Sun 22 November 2009, 04:54

...another reason to love the metric system.

J.R. Hatcher · #55 Wed 02 December 2009, 14:32

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.

Regnar · #56 Wed 02 December 2009, 14:45

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.

domino11 · #57 Wed 02 December 2009, 18:57

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

J.R. Hatcher · #58 Wed 02 December 2009, 20:02

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

domino11 · #59 Wed 02 December 2009, 20:59

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.

J.R. Hatcher · #60 Thu 03 December 2009, 06:07

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