Extended-length bright zinc plated "acorn head" (rounded top) leg bolt for Williams, Bally, Data East, Sega and Stern pinball machines.
These bolts are 1/4" (3 threads) longer than the standard leg bolt to accommodate the extra length needed for leg protectors, drink caddies, and leg plates with pim nuts.
References:
Wms/Bally #4322-01125-40
Data East/Sega/Stern reference #231-5001-01