Drilling heat treated ATS-34

1984nitro

1984nitro

Joined
May 22, 2008
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I went and got two blades ready for some liner folders. I heat treated them but forgot to drill the the thumb stud hold first. Now I need to drill the whole. My regular drill bits won't drill it. Is there a drill bit that will? Can I anneal the blade drill them and re heat treat?
Thanks for the Info
Eric Knight
 
I dont know if annealing/ re-heat treating will work or not, but drill wise; the only thing I can think of is a carbide drill and alot of coolent or oil. It'll work but that drill is gonna' cost alot of cash.
 
carbide bits at a slow speed and much coolant can work, but I've busted some bits just on hardened liners not near as thick as a blade, and they are pricey. Another option would be to grind on an indent in the blade, since grinding is much easier than drilling. Like this Spydie Jess Horn, or some variation on the theme.
 

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Thanks for the info. I wasn't sure the carbide would work but I will try if now. I can get 1/8" drill bits from north coast knive.com for cheap. I will let you know if it works
Thanks
Eric Knight
 
I run my carbides at the highest speed and get them in the two flute type or spade drills at MSC. If its a 2-56 screw hole I found the #44 seems to work best for fit even though the books call for a #43.

Them carbides are high $ and the smaller ones break pretty darn easy on the exit particularly if you are going too slow with it. Take it fast and let up on the downward pressure just before exit. It seems to help keep em from shattering if you have a scrap piece of some other hard steel on the underside but another tid bit I've found helpful is that its best to tape off the underside where it lays flat or the other piece of steel or grit or both can scratch the tar out of your good blade.

STR
 
I have drilled thumb stud holes on heat treated 154CM with carbide, it will be fine. STR's advice above is all good info, go get your carbide bit and put it to use :thumbup:
 
I,ve been running my carbide spades at 800rpm (on unannealed files)an thought i was doing it right.I can go as high as 3100rpm do ya,ll think thats too fast ?
 
You want either carbide bits or powder coated HSS bits. Carbide bits are designed for high speed and should be used around 2x as fast as HSS bits (check on this) and with much less feed as well as plenty of coolant. As for powder coated HSS bits, I can't help you much in that area as I'm not sure what type is needed and I'm not familiar with them. I do know that they are tougher then carbide though.
 
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I don't know of any HSS drills that will go through hardened steel. Most HSS bits are M2, which can be very sharp and hard, but it's not going to be enough to put a dent in heat treated ATS and definitely not a hardened file. Carbide is the tool for this job.

Carbide bits are expensive and I use them as little as possible. If you want good info on using this type of tooling, search around for posts by Nathan the Machinist on the subject.
 
Check ebay, resharpened carbide bits can be found at pretty fair prices. Like mentioned, they go fast and hard or they break. A drill press is a must, I would not recommend trying one in a hand drill.
 
AcridSaint...that's why they would have to be coated HSS bits. I'm just not sure of what type of coating you would need, but I know somebody who probably would so if I don't forget, I'll ask him.
 
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I have seen black or grey oxide coating and ti nitride coating, none will help HSS bits cut through hardened steel. If there's such a coating that can be put on M2 or similar steels, then knifemakers would love to know about it, because all coatings abrade off without too much effort.

There are masonry bits where have carbide tips and some folks use them to drill holes in hardened steel. I don't find that they are accurate enough for something like a thumb stud and my experience trying to drill hardened A2 with one turned me off of them for good.
 
You can buy carbide-tipped drill bits as well. They are cheaper than solid carbide. I've used them on hardened cro-moly (4130), but don't know about knife steels. It will likely be tough going but they should work.

Mcmaster has them, but they can charge a lot for shipping.
http://www.mcmaster.com/#catalog/115/2414/=3ezqyy

Carbide bits (or carbide-tipped) can go through nearly anything- but beware of chatter and vibrations in your setup. Carbide can chip very easily if you make contact too fast, or anything is jerking around.

I doubt think any sort of coated HSS drill bit will work in the hardened version. The cheap TiNi coatings rub off the tips quick and the bit will be dull before you've made it all the way in the hole. Annealing the steel, drilling, and re-heat treating later would be the ideal solution- will save you a lot of nasty machining.
 
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