On Monday, February 2, 2015 at 12:38:43 PM UTC-8, DerbyDad03 wrote:
As far as I can tell, the standard material for Cross Cut Sled runners is hardwood and typically 2 are used. However, I saw a couple of plans that use aluminum

Hardwood, waxed, works fine. My saw lives in a shed, and dissimilar
metals in contact can be troublesome (so the aluminum idea bothers me).
Rather than glue, or predrill and screw, I used POP rivets (so
that's SOME aluminum content). A POP rivet head needs very little
countersink depth, and the sled was 1/4" plywood.