Drilling pin and lanyard holes problems

D

Dave Hub

Joined
Dec 10, 2014
Messages
57
So is there a trick to drilling these holes? I am working on my first knife and using 5/32" thick ATS34. I am drilling 5/32" pin holes and a 1/4" lanyard hole. Using a drill press set on the slowest setting (700 RPM I think), the blade gets pretty hot and the bit seems to bind just before I punch through the piece. Should I drill a bit, let it cool, and then finish drilling? Should I use some oil or some other drilling fluid? The first 75% of the hole seems to drill just fine. It's that last 25% that seems to be a problem.

Thanks!
 
I drill mine under water to prevent work hardening due to too much heat.
Just an old frying pan filled with a bit of water. Place the piece in it and start drilling at max speed without any issue.
 
( I am new to this, so take this with a grain of salt )

There are lots of charts and calculators for speeds to drill at. Seems like around 1200RPM is appropriate for the bit you're using.

Some questions to perhaps help clarify:
Is the first part sending up curly-q's, chips, otherwise?
Are they discolored in any way? Especially blue or brown?
How does it sound? Does it chatter, make a high pitch chirp, or otherwise as you drill?

One thing that helps with the binding at the end can be to put a backing material below the target, such as some scrap metal, or even wood. This can help stop the bit from pulling too hard after it starts to break through, which may cause the binding.

A dull bit, too slow of a feed rate, or an off-center drill point could cause some heat build up.
 
I second the suggestion of having some sacrificial steel or aluminium behind what you are drilling. Let the drill continue to cut into the scrap metal. Steel is good as it will cut the same as what you are drilling. Aluminium is good because it conducts the heat away faster than steel.
 
Thanks for the advice. To answer a few questions, during the first 75% I get curly-q's. After that it's chips. I didn't notice any discoloration, but I will look next time. Yes, there is a high pitched squeal or chirp sound near the end of the drilling.

I think the backing piece makes sense, and I will try that.

Also, how much pressure to apply? I was trying to go slow, but maybe I am going too slow.
 
Step drill
Meaning a little drilling than come up out of the hole.
Go back in for a little more than back out of the hole.
And so forth till your thru.
Give a little force but let the bit do the work.

And clean shavings off the bit no need to drill that metal twice.
 
I had tons of trouble drilling when I first started making knives a few years back. I was using the home depot whatever name brand and burning them up constantly. I bought a set of Cle-Line drill bits and the clouds parted and the sun started shining. They are expensive but oh so worth it. A piece of flat wood under the work piece does help.
 
Dave Hub said:
Thanks for the advice. To answer a few questions, during the first 75% I get curly-q's. After that it's chips. I didn't notice any discoloration, but I will look next time. Yes, there is a high pitched squeal or chirp sound near the end of the drilling.

I think the backing piece makes sense, and I will try that.

Also, how much pressure to apply? I was trying to go slow, but maybe I am going too slow.
Click to expand...

well its been awhile since I had to drill lots and lots of holes at a time. I was having the same trouble you are describing. It took me a couple broken bits but what I found is that my drill bit was starting to flex under the pressure, causing the second half of my hole to start chipping and all that ugly stuff. Finally realizing what was going on I sunk the drill in the chuck so only about .75" was sticking out. It took a few tries to chuck it to spin true but that made all the difference in the world.
 
Taximanny said:
Step drill
Meaning a little drilling than come up out of the hole.
Go back in for a little more than back out of the hole.
And so forth till your thru.
Give a little force but let the bit do the work.

And clean shavings off the bit no need to drill that metal twice.
Click to expand...

in the machining industry this is known as peck drilling :-)
Peck drilling does a few things including breaking up the chips.
 
You might try drilling smaller holes to start and working up to the finished size. Cutting oil helps carry away some heat.
 
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