The tommy lock is made of steel plate and angle iron and it's welded on all seams . the steel is primed and painted . The lock is 5/8 stainless steel and has no neck down which is a weak spot on other locks, seals are on both ends of the lock to keep water out .
This stainless pin is more expensive but you would not want to skimp on this part the key is side cut design and has a serial # , and it can't be copied .
Also available in Galvanize for more info.