Pin buttons are typically used in extreme duty applications where the pin hole intersects the oil ring groove. Not only does the button give excellent support to the bottom oil ring rails, but they can also be removed much quicker than oil ring support rails and pin locks. Pin buttons must be designed and machined to fit a specific piston set. Available for all bore sizes, pin lengths, and pin diameters. Each set of buttons custom machined from heat-treated billet aluminum bar stock.