FK RSMX Series rod ends are 3-piece, extra-strong rods with heavy-duty shanks. Their alloy steel bodies are heat-treated, chromate-treated, and zinc plated for strength and durability. Their durable 52100 steel balls are heat-treated and hard chrome plated. RSMX Series rod ends' steel alloy races are heat-treated, zinc plated, and chromate treated for additional strength. Self-lubricating PTFE liners are available with these rod ends.