On 9/4/2010 11:18 PM, Larry W wrote:
In ,
J. wrote:
On 9/4/2010 9:01 AM, Larry W wrote:
...snipped...
I've read that too. And perhaps worth trying, use a HIGHER speed. Various
drill speed charts I've seen for forstners recommend something around
1200 or 1500 RPM for a 7/8" bit in hardwood.

This particular bit is clearly marked "Max 870 RPM".

If you know of such a chart online I'd like to see it. All the generics
I find say 500 RPM for hardwood.


Sure, here's a couple:

www.ibiblio.org/twa/info/drillSpeedChart.pdf (pdf warning)

And it says 500 RPM for hardwood.

http://www.woodcraft.com/Articles/Ar...?articleid=380 (chart in
right sidebar about 1/2 way down the page)

That article also discusses carbide and high speed steel bits and is not
at all clear whether that chart is safe speeds for carbon steel bits or
best cutting speeds for carbide or what.