Recommendation? Drilling Hardened Steel

[Natlek]

Thank you to everyone for the advice!

For some reason I didn’t get notifications for the other responses. I went ahead and took N Natlek ‘s.

Worked like a charm. Nice clean holes, made chips not dust, but went through with minimal pressure at 1175 RPM

These are the cheap bits to have if you need em.

Well , lucky you You can go to store and buy what you need .I spend half hour resizing 4mm tile drill bit into 3mm drill I whish I can do that here ...........good morning , i need two 3mm drill bits for ceramic tile ....thanks !
Well resizing was successfully I managed to drill two hole for two bolster pin ................

 

[Natlek]

[QUOTE="Cushing H., post: 19753981, member: 518872"
Back the material with something like aluminum, and buy multiple bits - they break[/QUOTE]


They will not break if under steel you drill you use hardened steel not aluminium .When tip of drill make small hole/opening on oposite side , lower the pressure .You will notice that tip was out on other side by chips..they will be bigger and drill bit will cut easier and faster.What left on steel in hole can not suportt pressure from drill bits and it will break ...and that can break carbide tip to.Using hard steel under help tip not to break..cutting will last little longer but will save dril bit . I hope you understand my broke English .....