The cam lever was made out of hickory only because I needed something thicker than the maple that I used for the pony. Make it out of something that is tough to resists the force and not break out the end where the cross bolt is. The cross bolt is made from 1/2" diameter cold rolled steel and threaded for 5/16X18 TPI to accept the 5/16" carrage bolt. I saw this on Youtube so it's not my idea. The wedge block spreads the jaws apart to insert the leather. The jaws have 3/16" valve cover gasket material (cork/rubber mix) glued on.