With traditional threaded block designs, when you use the arm you create forces that are concentrated right on the threaded portion of the arm - its weakest point. This is where arms typically break.
CALLAHAM ***AGED RELIC DE-SHINED***VINTAGE NARROW STRAT BRIDGE KIT (CA21030)
CALLAHAM VINTAGE STRAT STYLE BRIDGE COMPLETE KIT (CA21001)
CALLAHAM VINTAGE STRAT BRIDGE KIT EX AGED FINISH (CA21039)
Callaham Vintage Style Bridge Plate for Stratocaster Vintage Retro Part
Callaham Vintage Style Bridge Plate for Stratocaster®
Callaham Vintage Hardtail Bridge - w/ Specialized Brass Tele Saddles for Bigsby