RUKO GmbH Screw Extractor Size 4 for M12 Threads, Left-Hand Spiral, DIN 3126 Drive

When a bolt shears off inside a threaded hole, a mechanic reaches for a RUKO screw extractor. This size 4 extractor is made for removing broken screws, studs, and bolts with an M12 thread. The left-hand spiral bites into the drilled-out core and backs the fastener out without damaging the surrounding thread.

Key specifications

• Extractor size: Gr. 4
• Suitable for thread size: M12
• Material: High-grade tool steel
• Drive type: Square drive, 8 mm
• Extraction direction: Left-hand thread
• Recommended drill bit diameter: 7.5 mm
• Overall length: 60 mm
• Body diameter (max): 10 mm
• Flute type: Tapered, multi-flute
• Finish: Bright / polished
• Standard compliance: DIN 3126 (drive end)
• Packaging: Single piece

Why choose it

The tapered multi-flute design provides a strong grip in the pre-drilled hole, while the left-hand thread ensures the extractor tightens as you turn counterclockwise. The polished finish reduces friction and helps prevent the extractor from slipping.

Ideal use cases

• Removing broken bolts from engine blocks, gearboxes, and machinery
• Extracting snapped studs from exhaust manifolds and cylinder heads
• Repairing stripped or damaged threads in industrial maintenance

Good to know

Use a 7.5 mm drill bit to prepare the broken fastener. The square drive end fits a standard 8 mm tap wrench or socket. This extractor is sold individually, so you can replace only the size you need.