Drill Chuck Key Type Self-Ejecting S-K3C Key Size S-K3C Pilot Size 5/16 in Material - Machining Steel Features Soft Steel Handle Limits Potential for Dangerous Fracturing Under Excessive Load Spring-Loaded Ejectors Ensure Key Disengagement After Tightening For Use With 3M312 3M315 3M318 3L854 3M522 3L856 3L876 3L866 3L852 3M341 3L862