SPIRAL FLUTE SCREW EXTRACTOR - NO. 5Century 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. 5 size - removes fasteners 3/8" to 5/8"
- Pilot hole: drill 19/64" (left-hand bit preferred - sometimes backs out the fastener before the extractor is even needed)
- Use case: large bolts (3/8" through 5/8"), automotive cylinder-head bolts, intake/exhaust manifold studs, and engine 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: 73405
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.