Source for 2 -3/4- 4 tpi tap

[garychipmaker]

I am looking for a quick source for a 2-3/4"x 4 tpi tap. A bad day @ work . I broke the only 1 we have.

 

[Finegrain]

Hoo boy, how do you break a tap that big?

 

[memphisjed]

Dang....how big was your cheater bar?

 

[Cole2534]

Hoo boy, how do you break a tap that big?

I was in a shop last week that had some big Carlton radials (maybe they were #4's? They had 19" columns.)....I've no doubt they'd twist off that tap.

 

[Nmbmxer]

Try Regal Cutting Tools, they have popular specials in sizes that large though they don’t list 2-3/4-4 but they list 2-3/4-12

 

[Milland]

2-3/4 - 4 Special Pitch Plug Tap, High Speed Steel

2-3/4 - 4 Special Pitch Plug Tap, High Speed Steel

www.victornet.com

They may have other choices in that thread size, give them a call.

 

[garychipmaker]

had it in a 340 G&L boring mill. was tapping a cast steel housing to install a custom thread insert. on the second hole I went a half turn too much in a blind hole. and broke the shank with 4" of tap in the hole. OOPS I haven't tried to get it out yet except trying an air chisel rattling on it trying to get it to turn. It shocked me as i was turning it 7.5 rpms and the mill didn't stop as it was inching it .



















'

 

[Milland]

A CBN-grit hole saw may be in your future...

 

[Cole2534]

had it in a 340 G&L boring mill. was tapping a cast steel housing to install a custom thread insert. on the second hole I went a half turn too much in a blind hole. and broke the shank with 4" of tap in the hole. OOPS I haven't tried to get it out yet except trying an air chisel rattling on it trying to get it to turn. It shocked me as i was turning it 7.5 rpms and the mill didn't stop as it was inching it .

15hp at 7.5rpm is ~10,500ft-lb.

 

[Tyrone Shoelaces]

had it in a 340 G&L boring mill. was tapping a cast steel housing to install a custom thread insert. on the second hole I went a half turn too much in a blind hole. and broke the shank with 4" of tap in the hole. OOPS I haven't tried to get it out yet except trying an air chisel rattling on it trying to get it to turn. It shocked me as i was turning it 7.5 rpms and the mill didn't stop as it was inching it .



















'

I’ve got similarly buried taps out with a spark eroder and an apprentice plus lots of time.

Regards Tyrone.

 

[gbent]

There is one on the 'bay.

As long as the tap isn't shattered should be easy to weld a nut to it and back it out. Lots of room to work.

 

[4GSR]

Blow it out with a cutting torch. Yikes!!

Checked my stock on taps. I have a 2-1/2-4 and a 2-3/4-6. No 2-3/4-4. I tried.

 

[garychipmaker]

I got the tap out by using an Air Arc gouging rod. Supervisor found a tap in Chicago so it should arrive on Monday. Thanks for the comments

 

[Limy Sami]

Hoo boy, how do you break a tap that big?

I take it you've not met his cousin?