You really don't want any any ferrous metal near your cartridge. It will change the flux pattern of your magnet. Have you tried any of your local hobby supply houses, or Ace Hardware for stainless, brass, plastic or alloy? Here's a link to a mounting kit:(http://www.extremephono.com/Cartridge_kit.htm) You'd better ask what length he supplys as most mounting screws are 3/8" or less. If you have a McMaster-Carr catalog available to you, you could no doubt find some in there as well.