Kolvoii Helicoil Thread Repair Kit 320-Piece — Metric & SAE, 280 Stainless Inserts and HSS Tools

Kolvoii's 320-piece helicoil thread repair kit is a complete metric and SAE solution that restores, reinforces, and replaces stripped or damaged threads in metals.

This professional-grade kit gathers taps, drill bits, installation tools, break-off tools and 280 corrosion-resistant wire inserts in a single, organized case so you can repair threads quickly at the shop or in the field. Built for both SAE and metric sizes, the set targets commonly stripped threads—from small machine fasteners to larger engine mounts—using hardened HSS cutting tools and stainless-steel inserts engineered for lasting strength.

How does this kit restore stripped threads?

The Kolvoii system follows a simple three-step process: drill out the damaged thread to the correct diameter, tap a new oversized thread, and install a helicoil insert that forms a durable internal thread. Inserts are locked in place and the protruding tang is cleanly broken off for a smooth, ready-to-use finish.

• Precision-matched drill bits with 135° apex angle for accurate pilot holes
• High-quality taps to cut proper oversize threads for insert seating
• Installation drivers ensure consistent, flush insert placement
• Break-off tools remove tangs cleanly so bolts thread freely

Which sizes and materials are included in the set?

The kit covers both common SAE and metric fasteners, so you won't need multiple specialty sets. It provides inserts and tools sized for small to medium fasteners used across automotive and machinery applications.

• SAE sizes: 1/4", 5/16", 3/8", 7/16", 1/2"
• Metric sizes: M5, M6, M8, M10, M12
• 280 stainless-steel inserts and 10 of each tool type for repeated repairs
• Durable HSS drill bits and taps suitable for aluminum, iron, and steel

What performance and durability can I expect?

Inserts are manufactured from corrosion-resistant 304 stainless steel and often create threads that resist wear better than the original, especially in softer metals. Cutter tools are heat-treated HSS for long life, and the ergonomic handles and rubber-coated grips provide control during repeated use.

• 304 stainless inserts resist rust and maintain clamp strength
• Heat-treated HSS drills and taps for extended service life
• Ergonomic installation tools reduce user fatigue and improve accuracy
• Organized carrying case keeps tools protected and ready to use

How easy is it to use this kit for automotive and workshop repairs?

The kit is designed for straightforward, repeatable repairs by mechanics and DIYers. Clear drill/tap sizing and the intuitive install–break-off workflow let you complete most thread repairs in a single session without specialty machinery.

• Step-by-step Drill → Tap → Install process for consistent outcomes
• Pre-sized components cut down measurement time and guesswork
• Portable case keeps a mobile workshop organized for roadside or shop work
• Suitable for spark plug threads, engine mounts, brackets and more

Who is this for: This Kolvoii 320-piece helicoil kit is aimed at professional mechanics, maintenance technicians, fabrication shops and serious DIY enthusiasts who need a single, reliable thread-repair system for both metric and SAE fasteners. If you repair engines, machinery, or structural components where stripped threads cause downtime, this kit provides the durable inserts, hardened cutting tools and organized portability to get repairs done correctly and repeatedly.