Tapping 3/4” Left handed NC.

[Janderso]

Any pointers?
I plan on tapping this band saw vise block tomorrow morning. I am going to hold it centered in the four jaw chuck and use a bit of force from the tail stock.
Seem reasonable?
Tap handle centered on a center with constant pressure as I go through the left handed process.

 

[Ray C]

Are you going to power tap this or hand-spin? Either way, it looks fine.

Ray

 

[rock_breaker]

That's a big tap! Let us know how it turns out.
Have a good day
Ray

 

[P. Waller]

Morse taper tap holders work well for this operation, I have found them reliable up to 2 1/2-4 threads.
http://www.collistoolholder.com/cgi-bin/parts.cgi?typ=CAT_9_TYP_U

 

[Janderso]

I am planning to hand tap. I like the idea of a stable, 90 degree tap introduction. I’ll put a parallel between the chuck and the work.
I like the idea of the Collis holding device but..... more $ on even more tooling. I have a tap handle with a pilot hole for centering.
Here we go.....
PS, I am now a paid supporter of this forum, I have received so much good information and probably saved money due to the resources and ideas gleaned from these pages. Glad to invest.

 

[Dave Paine]

As rockbreaker said, 3/4in is a big tap. I have hand tapped aluminium at this size, but not steel. If I needed to tap 3/4in steel I would single point.

A sharp tap will help but still will need a lot of force. Use cutting fluid, it helps a lot, and a wrench on the tap and another one on the chuck jaws.

Let us know how this works.

 

[Janderso]

Finished. The 3/4 thread was a workout. Left hand threads, the chuck wanted to come off. I wedged the chuck and took it slow. The 1/2 threads were easy in the vise.