We like using a spring rivet because you insert it inside the stack pin and forget it. It can't be lost as there is positive pressure from the spring mechanism which holds the tits. Ends are riveted solid metal for superior holding power, not stamped as many of our competitors use and they will resist shearing if shear forces should ever be applied. Stamping makes a hollow tit that collapses under load. Under high load such as wind you might as well not have them... as they are useless. Hard chrome plated to resist rust.