1/8" lathe bit blanks _ AGAIN

[DFHicks]

I checked out the cobalt steel bits as recommended in a couple of the responses.  Went to ENCO and part of the "select product" drop down box selections was the % alloy.  It started at 5% and went up several more higher percentage levels.  What percent should I purchase?  Nothing is ever simple, right?
Greg

[ddoyle]

What ever %cobalt  you buy move your grinder outside, wear a mask and do not eat potato chips till you wash up.

In the very limited experience I have with HSS lathe cutters I have found that my cheap china M2 blanks once sharp are pretty tough to dull. Turned/hogged away at a bunch of 5/8- 3/4 hard bolts (maybe 3 hours of the lathe running) the other day and at the end looked at the bit with a magnifying glass. If there was a difference from when I started I could not see it and the machine did not notice any change. It would take alot of years of engraving to cover as many miles as that bit did.

By all means buy good tools but if you make a mistake on your purchase you are only out a few minutes at the grinder and few minutes at work. Grind something and get engraving!

[Acer Saccharum]

5% is fine for cutting steel.

[T*O*F]

It would take alot of years of engraving to cover as many miles as that bit did.

Not really.  Depending on what you are engraving, you could bust a point on the first hit.  Lathe bits and graver tips ain't the same animal.

[DFHicks]

Thanks again for all of the information.
Greg