oops

S

Scott the knife

Joined
Nov 1, 2002
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Oops. I heat treated my 44c blade b4 I drilled my pin holes to size:mad:
I have already drilled pilot holes @ a smaller size. Can I spot heat the holes to soften them back up so I can drill them the right size?? I was in a big hurry to finish this knife, and this sucks. Thanks for any help.:o
 
spotting it will help some but being an air quench steel it's going to be hard
if you are close to size get a carbide ream.
if you spot heat it you'll need to get up to about 1400-1500 deg F and try to hold it there for a while and let it come down slow.
but a Carbide drill bit and ream would be better than messing with it trying to hold the heats to temperature.

if this is a fixed blade consider making your pins to fit the holes..
the same possibly with a folder...I'm not sure of your situation..
 
If you accept the premise that a somewhat oversize hole isn't bad - then you have a number of options. With adequate epoxy, the fit is still tight and it even leaves a bit of give for expansion / contraction. You can sacrafice an old dull drill bit and just run it cherry red till it melts through. Only caveat there is to protect the blade from transferred heat. The tang will also need re-flattening around the new hole.

Alternatively, you can use the small cone shaped grinding bits that come with most dremel kits and just enlarge the existing holes. The little abrasive bits don't last long but they will grind hard steel.

You can buy a cheap set of diamond jewellers files and just chuck up the round file - same thing with cheap diamond burr sets.

Depending on hole size, there are other options. On my first knife, I discovered that a 1/4 inch pin won't go in a 1/4 inch hole. I used the slotted tip from a 22 cal cleaning kit - with strips of sandpaper in the slot and just sanded it out to size. (chucked up in the drill)

Carbide drill bits might do it - but they are expensive and you will break several in the process. Go slow.

:) Good luck. Most of us have been there at least once.

Rob!
 
If the hole is only slightly too small, you can put the pins in your drill press and spin them while sanding down their diameter. Works good for peened pins, but if their not to be peened you'd have to be careful to keep them perfectly round - pretty easy to do, though, with the drillpress.
 
If you accept the premise that a somewhat oversize hole isn't bad -
Click to expand...
??
Carbide drill bits might do it - but they are expensive and you will break several in the process. Go slow.
Click to expand...

Rob why would you assume you'd brake carbide drills in hardened steel? it's one of the things they are made for.

also a 1/4" pin in a 1/4" hole is called a press fit,, it will fit..I assure you..
and if you go up to say a hole
1" in dia, 1.000
a common press fit will be the pin at 1.001 . just to give a ratio
I'd hate to miss lead the guy..:(
 
Just read in the new blade mag. where Wayne Godard uses masonry bits to drill hardned steel. I haven't tried it yet, but as long as the bit was sharp and you went slow it should drill the hole just fine and there a heck of a lot cheaper than carbide spade bits.
 
I have done that before also except no pilot holes. It went back in the forge and got annealed, AGAIN! PITA! That is when I had yet one more reason to bite the bullet and fork over 1 1/2 bills for a US made carbide bit set.:D
 
Use a carbide tapered reamer.The suppliers sell them for around $20.Check Texas KS,Jantz,K&G. I use one regularly to adjust and enlarge hardened holes.
For a quick fix,use a cheap masonry carbide bit.As Rob pointed out oversize holes aren't necessarily a bad thing,so don't sweat the hole size,just use a bit size that will work.
 
Being a new knife maker and constantly screwing up everything I touch, I had this same exact problem just recently. I fixed it by buying a 12$ carbide cutting bit for a dremel at the local Ace hardware. Cuts through like butter.
Matt Doyle
 
It seems every 5th knife or so I have to drill hardened steel. I bought a bunch of used carbide drill bits on eBay for a song. Some are too worn out to use and have to be pitched but enough of them are good shape and work just fine. I sharpen them in my Drill Doctor.
Drill slow and use lot's of cutting oil. You should see little chips/flakes when drilling. If you see dust or chunks from drilling you need to adjust your speed or pressure. Drill a practice hole or two in the handle where it won't be seen.
 
Thanks for all the help guys. Inever thought of the dremel.The masonary bit sounds worth a try.I,ll update later. Thanks alot!!!
 
The masonary bits work very well when, as in your case there is a pilot (UNDER SIZED ) hole. They don't hold up well at all but are very cheap. Just consider them expendable at Around a buck or so. I do not want to step on any toe's here, as any advice is well meaning, but "DO NOT" spot heat 440-c!!! As an air hardning tool steel, you will put tremendous stress in the blade,and or handle. Depending on how far away the hole is from the cutting blade, or ricasso. This will require annealing, and re-heat treating. A seriously long process. If you were willing to go thru all that, you would be able to wait for the annealing to drill the holes larger in the first place. It would be cheaper in the long run to throw the balde in the scrapp heap, and start again, than to go thru all that trouble. A masonary bit can be had at Lowe's, home Depot, Sears, or just about any builders supply, dirt cheap. Buy several for the next OOOP"s!!! They happen! Mike Lovett
 
mlovett said:
The masonary bits work very well when, as in your case there is a pilot (UNDER SIZED ) hole. They don't hold up well at all but are very cheap. Just consider them expendable at Around a buck or so. I do not want to step on any toe's here, as any advice is well meaning, but "DO NOT" spot heat 440-c!!! As an air hardning tool steel, you will put tremendous stress in the blade,and or handle. Depending on how far away the hole is from the cutting blade, or ricasso. This will require annealing, and re-heat treating. A seriously long process. If you were willing to go thru all that, you would be able to wait for the annealing to drill the holes larger in the first place. It would be cheaper in the long run to throw the balde in the scrapp heap, and start again, than to go thru all that trouble. A masonary bit can be had at Lowe's, home Depot, Sears, or just about any builders supply, dirt cheap. Buy several for the next OOOP"s!!! They happen! Mike Lovett
Click to expand...

Mike if it's my toes, no problem :D
I should have mentioned if you do spot it , to retemper the blade, but I still say rework the pin or go with the Carbide drill :)
Cobalt is good too if you get real cobalt ;)

I mentioned re-working the pins because many times you can't get pin stock at the correct size anyway so I don't fret over the hole size if it's not right,

cool it is but if not I resize the pin..it looks good, fits good and who knows if the pin and hole is a bit under standard?,
what is standard anyway in knife making.

it's just with me at least, why spend more time on another problem you can make for yourself? don't get me wrong I'm not hacking any fix's here they are all good and will work. I worry about my time if I goof up..

one thing new guys or old can do with what Rob mentioned about an over size hole
you can do this on propose to slightly move scales where you may want them
if for some reason they need to be moved..
as he said the epoxy will set the pin in it's new place and your good to go.
:thumbup:
 
Scott the knife said:
Oops. I heat treated my 44c blade b4 I drilled my pin holes to size:mad:
I have already drilled pilot holes @ a smaller size. Can I spot heat the holes to soften them back up so I can drill them the right size?? I was in a big hurry to finish this knife, and this sucks. Thanks for any help.:o
Click to expand...

If your holes are already larger than 1/8" and you have a dremel tool, go to Sears and buy a 1/8" straight carbide cutter, It will cost about $6. You can run this as fast as 25,000 rpm. Work around the inside of the hole till it's the right size. Don't exert heavy preassure, the tool is solid carbide and will snap. let the tool do the work. Don't bother with tooling fluid it will just be flung off.
 
True enough Dan! All these things will work. I use a 2+2+2 in heat treating 440-c. Drilling out the hole just seems a lot quicker. Mike
 
:thumbup: Carbide tipped masonrybit$ 6.00
Cutting oil $3.00
Clean holes thru hardened steel......PRICLESS!!!:D


Thanx for the help guys:thumbup: :) :D :thumbup:



BACKTOTHEGRINDER....Scott
 
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