1.750 MT drill bit

[Aukai]

I'm going a little cross eyed looking on line for a MT3-MT4 1.750 drill bit. National has MT5, Michigan drill has one but it's 600.00 dollars. I have my 2" aluminum bar that needs to be drilled out to 1.75 x 10", I have been able to bore it out, but for production purposes it will be faster to drill it on the lathe. Interstate on MSC is another one I've found, any other companies I could look at?

 

[jwmelvin]

What about an insert spade drill? Maybe they require coolant through for chip evacuation.

 

[Aukai]

I only have mist coolant available, but maybe I can peck to unload it? Finding holders, and lengths gets expensive too.

 

[Reddinr]

How about starting with hollow round bar stock and bore it to ID in a couple of passes? I've done this from time to time.

 

[Aukai]

I also have a taper feature that would rule that out, 2" down to ~1.220" for the handle.

 

[jwmay]

I've got a large carbide spade type insert up for trade in the trading post.

 

[JRaut]

I've got a big MT5: 1-13/16 (1.8125") drill bit. [EDIT: It might be a MT4, I'll have to measure.]

It's wayyyyyy too big for any of my machines.

Either new old stock, or newly sharpened (with the wax still on it).

If you can deal with 1/16" larger than your target, it's yours for whatever reasonable asking price you pick. Should be able to fit in a flat-rate box.

 

[Aukai]

Does it have 10" flute length? I would have to stack adapters as well.

 

[JRaut]

I think the flutes are exactly 10" long, yes.

I'm not in my shop but can measure tonight and let you know for sure.

 

[Aukai]

I just went, and measured my wall thickness, and 1.750 Is as large as I can go, I may have to down size from there even. If I have to clean up the outer diameter too much.