Combination drill/counterbore for standard cap screws; sources?

[specfab]

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

They also have these in metric sizes. I have used them before, and they did an OK job, if your dimensions line up with the offerings.

 

[BT Fabrication]

yep, my local tooling rep got me a HSS step drill to do 1/4" holes and 3/8" 82 degree counter bore to do a run of parts with about 9 holes per part for 20 parts. for $30 for the bit, made life 100X easier. Is there a local cutting tool supplier there? Worst case is you get a drill then an indexable carbide chamfer mill like "Nine9" has.

 

[ShaunM]

These look like something I could also utilize as we drill/counterbore a lot of holes for 3/8" SHCS's.

What speeds would you run these? Faster for the clearance hole then slow down when you reach the c'bore portion or one speed for all?
If I bought an off-the-shelf unit from McMaster to try out, the step is 7/8". We drill through 1" 1018, would it wreck one of these tools to have both the clearance drill and counterbore engaged in the cut at the same time? Wouldn't think so but hoping someone has experience with them.

 

[Nerdlinger]

We use a company called Great Lakes for sharpening tools and they happily modify std drills like this when we don’t have room for separate tools in our older lathes. Good luck!

 

[specfab]

In my usage of the McMaster drill/counterbore tools, I was working on modifying cast aluminum parts, so no real idea about how they would perform in steel. They worked well on the parts I was making, with full engagement of both drill and counterbore diameter, though. This was on a manual drill press, I might add, so not the most rigid setup in the world.