From the Benchmade site
"M2- A very tough, tool grade high-speed steel used primarily as a cutting steel in the industrial area. It offers excellent strength and wear resistance. Due to its make up, it is highly susceptible to corrosion, so we always apply our BK1® BenchKote coating for corrosion resistance. An excellent choice for hard use environments."
See Benchmade M2 steel folder reviews for
Stryker by Peter Ervin
(http://www.benchmadeknives.net/revstryker3.html)
Mini AFCK by Cliff Stamp
(http://www.physics.mun.ca/~sstamp/knives/m2_mini_afck.html)
Hope this helps.
Krizzard, out
"...Whoever kills with the sword must be killed by the sword... "
- The New Testament, Revelation 13:10