pin and lanyard holes

G

gaspassah

Joined
Feb 13, 2009
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so i have 4 knives in varying phases of being done.. i've gotten to the point of drilling pin holes and lanyard holes... my questions are..
i'm drilling 1/4 in holes for stainless pins (1/4 in) and stainless lanyard tube (1/4 in) and the pins and lanyard tubing is REALLY tight.. should i being drilling larger holes? or just wallow a bigger hole with the 1/4 in bit?
secondly it takes forever to drill one hole. i'm using metal drill bits in a drill press.. but it seems the bit dulls before one hole is completed... am i doing something wrong?
thanks in advance
 
You want the pins to fit snug as they are essentially holding the handles on. If you are peening them, you will want to countersink the holes a bit so you dont crack the handle material. What speed are you using on your drill press and what type of bit are you using? You should use slow speed and some lubrication on non-hardened steel. You should splurge on the best HSS, cobalt or tungsten carbide bits you can afford. It will save you money in the long run.
 
Yes, cobalt bits and slow speed is the key. The problem with many small drill presses (mine included) is they turn too fast. Small cobalt bits (1/8th) and soft steel seem to work OK at 620 RPMs (the slowest my press goes) but bigger sizes or hard steel and you can just forget it. I've resorted to using my Dewalt cordless drill for doing larger holes or holes in hard steel as you can spin it as slow as you want.
 
Low speed on mine (~600 RPM) is good up to about 1/4". I was told 50 SFPM is about right for tool steels.

Are you using cutting oil, gaspassah?
 
The hole through the tang should be larger than the pin/tube. I usually make mine about 25-50% larger than the pin.If you make it a snug fit, alignment problems almost always crop up when assembling the handles at glue up time. The holes in the handle material should be a smooth fit....neither tight or loose. You should be able to slide the pin in and out with two fingers easily.
Drill all holes while the steel is annealed, use good bits and cutting/drilling fluid. Slower speed, too.
 
it appears speed is my major problem.. i didn't have any cutting fluid handy so i was using transmission fluid.. that choice was just a guess as to whether it would work.. i'm using ats34 and 154 cpm steels, they have not been hardened yet..
thanks for the replies
 
For the size problem, I use a bit slightly larger than my pin material so that the fit is loose enough to insert and remove the pins with my fingers, but not loose enough to have gaps. (Going from memory, it is an 'F' bit for 1/4" pins, #30 bit for 1/8" pins, etc.) Look up a drill bit size chart online to see which ones to use for your size pinstock.
 
IDK if it's exactly "kosher", but you can also reduce the size of the pin stock to fit by chucking it in a drill and holding sandpaper on it.
 
When I drill a hole in the tang I will start with a 1/8" bit and work up to 1/4" I buy 1/8" bits in quantity and treat them as disposable but I will sharpen 3/8" and larger bits. I too like the tang holes to be a little larger than whatever diameter pins or lanyard tubes I'm using this does help with alignment problems.
 
for annealed steel, I drill a 1/4 hole at low speed using hss bits. Then after the heat treatment and cleaning, I end up with a hair- 128th to 64th - more diameter. Just happens that way.

(for 1/8 and 3/16 pin stock I use 1/8 and 3/16 bits)

Here's the difference. Some "quarter inch" stock is bigger than other 1/4" stock. There's also going to be a change in diameter when/if you rough the surface of the pin/tubing stock to grab the epoxy/glue. I do a light pass on 80 or 100 grit, then check the fit in the handle scales. (since I drill the tangs first and there's never a problem with those.) Depending on details, I may use a bit that 128th larger when drilling the scales. And sometimes I'll have to ream afterwards- depends on the material.

If it's too tight, I'll take another quick pass on the 100 grit. "too tight" is a bit subjective. I want to get the pin through the handle assembly with light tapping using a hammer, but not whaling. If you can spin the pin in the hole with your fingers, it is definitely too small for the hole.


On a hole smaller than 3/8 inch, on stock 1/4 inch thick or less, I centerpunch and just drill. centerdrilling or predrilling isn't really necessary with a decent quality HSS bit on any annealed carbon steel I've touched. I use WD40 as cutting fluid. It works. I have "real" cutting fluid, which I use on the lathe and mill about half the time, but overall I seem to get better results with bulk WD40.

Most store brand "super" bits- carbide, tungsten, whatever they come up with- don't last. A decent HSS bit is easy to sharpen, works, and will last a while. I have a few solid carbide bits for when I pull a brain fart and forget to drill a hole or need to move a hole after tempering.

Carbide bits tend to be brittle, so with those I only chuck into a mill collet and use on the mill. If your drill press is solid and true, it will be fine, but carbide don't wobble, it shears.


I do ream the holes where I use tubing and then flare the tubing after glue up. For pins I will sometimes peen and sometimes not. If your adhesive has some room to grab the pin because of a good roughing pattern, it doesn't seem necessary. But, if peening, a little reaming of the holes for a slight countersink works out well.
 
Mr. Bad Example said:
IDK if it's exactly "kosher", but you can also reduce the size of the pin stock to fit by chucking it in a drill and holding sandpaper on it.
Click to expand...

:o why didn't I think of this last week :grumpy: I ended up ruining a handle because the fit was so tight between the pins and the handle/tang I peened them too wide just trying to tap them in.

well now I know what I'm doing next time when this happens.
 
thanks for all the replies. when all else fails, read the directions.. the drill press is setup on a pulley system,.. got it down to 620, works much better, i think with better bits it will be even better. tried a little quick grind on the pins, and lanyard tube, all works well now,
thanks guys.. ready to get this knife done
 
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