Trying to drill holes in hard steel - need help please !
Hi Everyone. I am trying to drill 3/4" holes through Rockwell C50 heat-treated chrome alloy. I can't find a drill bit that will last more than a few minutes, even with slow speed and plenty of cutting oil. Any ideas please?
You'll probably need to hard mill it with high quality coated carbide end mills with lots of coolant in a very rigid machine. I know we do it all the time at work and it works pretty good. I've even watched them mill a pocket with a 1/16" EM .250 deep in 50 rockwell C stainless and hold tenths to the bottom.
How many holes and how deep ? 50 Rockwell C is pretty damn hard .. Nothing high speed is going to hold up ..
You are going to need a milling machine and a carbide end mill. Make sure you setup a stop so that you just barely break through. If you plow through fast you will break the corners off of the mill and they don't give 3/4 carbide mills away.
EDM is another option .. good luck
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