Reply with QuoteWith a machine I would think, you would need a lot of torque to turn it.
Tapping 1-1/8"
Hello everyone, I'm tapping a 1-1/8" hole into aluminum.
Because this is such a large tap, should I use a machine to tap this hole or is it something I can do by hand?
Similar Threads:
Re: Tapping 1-1/8"
With a machine I would think, you would need a lot of torque to turn it.
Thank You,
Paul G
Check out-
[URL="http://www.signs101.com"]www.signs101.com[/URL]
Re: Tapping 1-1/8"
It really depends on the number of threads per inch (TPI). Standard pitches for 1-1/8" are 5,7,8,12,14,16 and 20 TPI,
the more threads per inch, the easier it will be to tap. I have tapped 1-1/8-12 holes in steel by hand, sometimes holding the work piece
from turning is the difficult task, especially round pieces, also the number of holes and depth. It will give you a
good workout, no need to visit the gym!
Re: Tapping 1-1/8"
Thread mill.
My 2¢
Re: Tapping 1-1/8"
I agree with Ian. If you're able to, threadmiling is the way to go. Now I bet some guys are gonna cringe, *buuut* I've had good results with a handheld drill. Just set it to its lowest speed and go slowly... I usually start it on a drill press to make sure its nice and square, then move over to a drill. Beats the hell outta doing it by hand and if you go slow, back it out every turn and USE OIL (tap magic works well with al) you should be alright. Also keep some air on hand to blast the chips and clean the tap every now and then.
***Ooops, read that as 1-1/8 depth haha.. not sure what depth you're going for but it shouldn't be too bad by hand. Again, just start off nice and square, use lube and air***
Devin
Re: Tapping 1-1/8"
We just got done with a 1"-8 in steel. In the flange of a large sprocket set on a post bolted to the table of our Bridgeport.
This is assuming you are only doing 1 or 2 tap holes like this.
This is how we did it;
We found position, drilled the hole, chamfered the hole and used a center (like a straight shank lathe dead center) in a .750" collet. All large taps have centers formed in the ends. Set the tap in the hole, insert the center into the formed center of the tap and maintain enough pressure to keep the collet center in the formed center of the tap while turning the tap. This might be best done with help.
We were allowed the use of a tap drill giving us 67% thread (.890") instead of the standard tap drill chart 77% (.875"). The larger the drill the easier the tapping but the less finished thread for engagement.
Plenty oil, occasionally alternating directions. We had a through hole so the chip pushed nicely with a plug tap.
1.125" in aluminum should be a piece of cake. Take your time
Posting Permissions
