Thread: What type of drill bit?

I have drilled hardened knife tangs with the masonry drill bits before, but have also melted some of those same bits, too Not sure if they have a size small enough to end with a 1/8" hole or not? I have some of the bits in 5/32", not sure of the final hole size yet. Carbide may work, or a narrow diamond bit in a Dremel? A #30 wire bit will allow clearance for a true 1/8" diameter pin w/o binding. A 1/8" pin will usually not fit into a hole drilled by a 1/8" pin.

Or you could just anneal the pivot area. A carbide drill is very fragile so make sure there is no lateral pressure or it will snap if subjected to torque. Carbide prefers high speed and plenty of cutting lube.

Originally Posted by Geezer

HF has many cheap sets of "diamond" jewelers' files. An hour spent could do what you wish.

That was my thought, a round jeweler's file:

Hmmm. Would cutting off the handle of the HF diamond needle file and chucking it into a drill press/drill/Dremel work faster?

There are carbide tipped metal cutting drills too, but they are expensive. A buddy of mine has carbide tipped end mills and has used them on various tough projects, like drilling into a weld, or steel adjacent to a weld. One thing he taught me, for reaming holes in tattoo machine tube vises, is to start that drill press and shut it down as you put pressure on the work. Back it off and start/stop again, and again, until you are through the work.

As when we used to ream holes on structural steel bridge and building work, get your reamer, in this case bit, spinning before you go to contact with the work. In the case of reaming holes on structural steel we went on through once we started. I reaming a hole thorough hardened razor tangs I'm not sure if that start/stop would work but it is less likely that you'll burn or break the bit IMHO. I could be wrong though, I was wrong once before.

Originally Posted by Geezer

HF has many cheap sets of "diamond" jewelers' files. An hour spent could do what you wish. Alternatively, the same source has a set of "diamond" Dremel bits which take a really light touch but will do the job.
Used both methods at different time to close a too large hole in a blade.
~Richard
PS. Not all tangs are fully hardened but some are.

Lacking a ridged setup and coolant that is needed for solid carbide drill bits, I have used both diamond needle files and diamond burrs on dremel type tools to enlarge pivot holes. There is not much metal to remove, the task goes rather quickly with a diamond file.

Charlie

Originally Posted by spazola

Lacking a ridged setup and coolant that is needed for solid carbide drill bits, I have used both diamond needle files and diamond burrs on dremel type tools to enlarge pivot holes. There is not much metal to remove, the task goes rather quickly with a diamond file.

Charlie

agreed,we are not building a mars rover Here?

Can you epoxy or deform brass into the hole and then drill?
That Rodgers I did had a funcky shaped hole, but the brass bushing just has to fit snug, doesn't need a perfect parent hole. JMO. You're just trying to reduce the slop right?

This takes all of 10 mins,Carefully enlarge the hole to the tubing size with a dremel carbide bit,chamfer the edges a bit with the round bit pictured.
Insert tubing,file to the flats of the tang,peen it in place,Is really very simple.

Originally Posted by pixelfixed

This takes all of 10 mins,Carefully enlarge the hole to the tubing size with a dremel carbide bit,chamfer the edges a bit with the round bit pictured.
Insert tubing,file to the flats of the tang,peen it in place,Is really very simple.

I'd looked at the dremel carbide bit but the site said it is not recommended for enlarging holes less than twice the diameter of the bit - however, I'm going to give it a go and do it carefully as you suggest.