What kind of bit should I find to drill into some hardened steel. I tried a carbide (iirc) bit and it wouldn't touch it. Thank you for your time.

Hey Robert,
Depends on HOW hard. If it is hardened tool steel such as 0-l, W-1, A-2 etc. It may not be able to be drilled without annealing first and then re- hardened and tempered. Especially if you aren't having any luck with the carbide bit. That's about as hard as a bit can get. What specifically are you trying to drill? BTW, when to coming to Omaha??

Scott what I am trying to do is drill into each end (horizontally) of the dist adv plate so I can put in 2 setscrews so I can adj the mech adv by rotating the dist around so I can access/remove the vac can to get to them/adj both/reinstall the can and turn the dist back to close to it's orig position & retime it. "the tool house" sold me I think it was a carbide bit and it made a slight depression and that was it. Not for sure if I can get up there in the near future, I have plenty of time but I am beyond broke . Any ideas w what I shared on what I need for a bit? I have those AVS rods/jets out if we can get connected & work something out. Are you jonseing to get it back together? Later. RR

I can't see a dist. advance plate being made of hardened steel!!!

How big of a hole are you drilling? The smaller the better ... working up to the final size. Once the first hole is drilled then the subsequent drills have an easier time. Are you center punching it first? If you can punch it you can drill it!

One key to drilling metal is the drill speed. Slow it down and it will cut. Spped it up and it will ruin the bit in no time.

Such parts are usually case hardened; the case might only be a few thousandths thick, if you can get through the case the rest will drill easier.

I usually use a carbide rotary burr to cut through the case.

I keep forgetting about case hardening. That would 'splain it too.

if it is case hardened, take a grinder to it and remove a little bit and your problem is solved. also of times i find the drill point to be wrong and won't let the drill start. ideally you want a split point 135° drill. also i would recommend cobalt as opposed to carbide. i have made this mod before and i don't remember the plate being hard at all. of course i was machining it on a mill.

Hey guys thanks alot for the tips/suggestions/recommendations. I forget the size but it was a small bit in a small harbor freight drill press and I put the belt on the slowest pulley combo. You know now that you mention it, it may have work hardened cause it made a slight dimple & even that was with alot of pressure so I knew something was wrong. I will get another bit (Cobalt?) and file the end and start over. Jerry I dont remember the angle but I will center punch it & see if that will let it grab/start. yeah I didn't think that it would have been that hard of material either, from how it went you've thought I was messing w titanium or something. You know now that I think about it after reading you guys' posts I think since I didn't use a center punch that I work hardened it trying to get the bit to start

You can buy a cobalt drill bit. I use them to drill out hardened screws at work.

Robert,
Generally, the smaller the bit the faster the feed and speed. I run 1/8" at about 800 - 850 rpm. Faster if using a coolant drench. Bits need to be sharp or your gonna burn the bit and over heat the work. We had some internally cooled 3/8" bits at work we ran at 3600 rpm. But that was a CNC machine