When I need some I don't have, I part off some 1/2 inch dia "O1" tool steel on the lathe... flame harden and oil quench, then grind them flat on my buddies surface grinder.
This is especially good when at the top/bottom of the range, or out of the range altogether... works for me.
We have also used 1/2 dia 7075 aluminum for the drag bike... but never recommend those soft ones for a street bike because they mushroom over time.
