drilling hardened s90v

peter r

peter r

Joined
Jun 8, 2009
Messages
1,690
i have a blade hardened to 61 rc is it drillable? i need to drill a 3/32 hole 1-2mm deep. i have a micrograin carbide bit and want to know how to proceed.
 
High rpm's say 2500-3000 very light pressure. Don't try to go straight through, break a chip and pull out. Don't use oil it will make the chips pool back into the hole. Ideal would be high pressure flood coolant on a mill. If you just have a drill press try using forced air to blow the chips away, while drilling. Go slow.
Good luck.
 
It will probably drill a small hole like that. Make sure to clamp the blade down rigidly and use some lube. Take it easy with the pressure. It's gonna be very hard on the bit!
 
i have a mill. so thats what ill use. hi speed lots of lube low pressure. ok sond good.
 
I've used carbide spade bits with reasonable "success" on hardened tangs.. they break very easily though, hard but brittle. I think keeping the chips out with air would probably have helped my cause. Thanks for that tip.
 
I've used this method on D2 at HRC60 so I'm guessing it should work on S90V at HRC61.

Using a Dremel tool and a small ball end carbide bit, hold the bit at about a 45 degree angle and grind out a small divot on each side of the blade where you want the hole to be. If the ball end is equal to or smaller than the desired hole size, keep going until the shaft of the burr hits the edge of the hole. once the two divots meet to form a hole, switch to a tapered solid carbide burr and slowly ease it in to expand the hole to the desired size. The burr will want to walk if you press too hard so you will have to concetrate on holding the tool steady. This process is slow and you will have to pause frequently to let the Dremel tool cool down. Could take up to two hours. I suggest you wear a dust mask, glasses and ear protection. A cold beer to suck on to break the boredom while waiting on the Dremel to cool also helps.

Enjoy!
Jim Arbuckle
ABS JS
 
I did this today with a piece of hardened 1075 plow blade steel.Yes,richardj's famous/infamous John Deere stuff.It was thin,about 1/8 and went fairly quickly.I dont have a drill bit that will put a mark on it.Ended up with some nice 1/4" holes.
DAMNENG said:
I've used this method on D2 at HRC60 so I'm guessing it should work on S90V at HRC61.

Using a Dremel tool and a small ball end carbide bit, hold the bit at about a 45 degree angle and grind out a small divot on each side of the blade where you want the hole to be. If the ball end is equal to or smaller than the desired hole size, keep going until the shaft of the burr hits the edge of the hole. once the two divots meet to form a hole, switch to a tapered solid carbide burr and slowly ease it in to expand the hole to the desired size. The burr will want to walk if you press too hard so you will have to concetrate on holding the tool steady. This process is slow and you will have to pause frequently to let the Dremel tool cool down. Could take up to two hours. I suggest you wear a dust mask, glasses and ear protection. A cold beer to suck on to break the boredom while waiting on the Dremel to cool also helps.

Enjoy!
Jim Arbuckle
ABS JS
Click to expand...
 
Try the spade carbide bits from Sheffields. I have used alot of other carbide bits and for me these work the best. I drill holes all the time in hardened (61 RC) D2 and it sure don't take a couple of hours. Like the beer part though. Seriously though these bits work great and I can get a hole drilled in about a minute or so. They are brittle so be careful. I use a slower speed on a drill press and cutting fluid. Gets er done pretty quick. I've also found that using a Blaze 60 grit on my flat disc I can touch up these bits or reshape a broken one.
 
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