Century Drill & Tool hardened tempered alloy-steel spiral flute screw extractor for removing broken screws, bolts, and studs. The left-hand spiral design bites deeper with each turn, providing continuously increasing grip for reliable extraction of seized or sheared fasteners that a straight-flute extractor would slip on.

• No. 4 size - removes fasteners 9/32" to 3/8"
• Pilot hole: drill 1/4" (left-hand bit preferred - sometimes backs out the fastener before the extractor is even needed)
• Use case: larger bolts (5/16" through 3/8"), spark plug threads, suspension and brake-caliper bolts
• Spiral flute design grips deeper as torque is applied, unlike straight-flute extractors which can slip
• Hardened tempered alloy-steel construction
• Square shank for use with tap wrench or adjustable wrench for controlled torque
• Manufacturer part number: 73404

Extraction Tip: Center-punch the broken fastener to keep the pilot drill from wandering, then drill the pilot hole straight and centered with cutting oil to reduce heat. Tap the extractor in with a hammer to seat the spiral teeth, then turn slowly counter-clockwise with a tap wrench. A snapped extractor is much harder to remove than the original fastener, so never use an impact driver or apply more torque than the square shank tolerates - if it does not move, soak with penetrating oil for an hour and try again rather than forcing it.