You can go to most any bolt supplier and buy 50 to 100 for just a few bucks.Try and buy them with at least 1/4" unthreaded shoulder and cut them to size,try and get 3/8" thread engagement.The high doller MPs with full thread tend to snap just below the heads if thightened to much.Alo you can get them with 5/16 and 1/4 twelve point heads and eliminate the pesky allen heads.