How long would a carbide drill last drilling steel

Yeah! M42 and such cobalt HSS are really great. The only thing they lose over carbide is stiffness, but for drilling, that shouldn't be an issue. They only cost pennies more than crappy plain HSS, and are so much better. For the larger sizes of end mills, Cobalt is the only thing I will buy. I haven't really made the move over to cobalt drills in a big way, but when I need to replace some, that's what I get.

For 1/8" end mills, I use carbide as they are SO cheap, and so much stiffer than HSS.

Jon

Iggy, I agree with Karl, but I would add that M35 or M42 Cobalt tool steel drills deliver the best performance and durability. however they are expensive and hard to find. Steve

brittle. HSS is far more forgiving. Till you've got a

Shrug..I do machine tool service and repair. Lots of CNC machines with ballscrews.

The Omniturn CNC lathe is one of my specialites. They are equipped with ballscrews. When the servos are turned off..its very very easy to apply pressure to either axis..and move them with finger tips.

I was told about a guy who equipped a Series 2 BP with ballscrews. Power axis on the X axis only.

While making the last cuts on a very time consuming job..he forgot to lock the Y axis

The table moved rather suddenly and cost him $8000.

But he sure liked ballscrews on his manual mill until that moment.

So perhaps in your experience...you work with machines that have their gibs tightened a bit harder than normal, or ?

Odd..I smell smoke....wonder where its coming from?

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

Very true indeed.

And the commonality is that X Socialists want to take all of your money.

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

deliver the best performance and durability. however

They are easy to find, just pricey. $4 for a 1/4 jobbers length bit.

How would you recognize them in a pile of used bits? More shiny?

brittle. HSS is far more forgiving. Till you've got a

deliver the best performance and durability. however

Slightly different color of metal (assuming no TiN coating on either). It helps to have one or two known ones to tune your recognizer. :-) Working from memory (not bothering to go down and look at my set) I would expect a somewhat bluer tint to polished bits.

Buy one in 1/4" (as a generally useful size to have on hand anyway) and use it as your reference. My set is #1-#60 -- plus a couple of 1/2" ones bought for drilling starting holes on the lathe prior to boring. That split point makes life a lot easier.

Also split points increases the odds.

And in a pile of used bits, they are likely dull already. And while they almost certainly came with split points, they may have been re-sharpened by someone who does not have a sharpening fixture capable of doing split points, so at the cost of some length, they will be shorter and have chisel points now, even if they started with the split points. (And the difference in performance after that may be why they are in toe box of used bits. :-)

Enjoy, DoN.

deliver the best performance and durability. however

And a somewhat more Brown case color.

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch