Spot Facing

[Matthew Hajicek - Singularity]

Harvey has some pilotless counterbores / flat bottom drills that work well for spot facing:

 

http://www.harveytool.com/prod/Browse-Our-Products/Holemaking-Solutions/Counterbores_144/Counterbores---Flat-Bottom_128.aspx

 

I just tried one on 17-4 H900 prepping for five axis drilling.  It was faster than interpolating with an endmill, you can do it with 5-axis drill instead of setting a plane and using contour, plus I was able to keep the spotface feature smaller which made close holes at different angles easier.  Just thought I'd share.

 

[The Cathedral]

We use those a lot. In fact, we have a job here that requires a very tight tolerance bore, very deep into thin wall part, with flatness on the bottom, so we had custom tools made up with coolant through. They work like a champ, even if they are $$$ for being custom. Wouldn't be able to do the job at a profit without them.

[jlw™]

Yep, you're going to put a minimum amount of money in some jobs no matter what. Whether it's buying the right custom tool or going over on time trying to do it the wrong way.