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.
B-Electric Guitar Tremolo Block Tremolo Block Enhance Sustain For Bridge
Tremolo Block Bridge with Wrench Block for Electric Guitars Instrumental
JS Randy Rhoads White and Black Lined Electric Guitar Floyd Rose Tremolo Ship US
Solid Brass Stratocaster Compatible Tremolo Block 11.3mm String Spacing
Musiclily Ultra 42mm Brass Tremolo Block For Wilkinson 54mm Bridge Strat Guitar
Musiclily Ultra 36mm Brass Tremolo Block For SQ Affinity 2-point 52.5mm Bridge