When sourcing parts for Sulzer projectile or rapier looms, you must prioritize material hardness and wear resistance. For components like projectiles (grippers), ensure they are made from high-grade alloy steel with specific heat treatment (HRC 55-60) to withstand high-speed friction. For guide teeth, check for surface smoothness and dimensional precision (tolerance within ±0.01mm) to prevent yarn breakage. Always verify compatibility with specific models such as the Sulzer PU, TW11, P7100, P7150, or G6100/G6200 series.