What extra supplies do I need to complete the repair?
The kit includes all essential tools. A tap wrench is not included.For best results, we recommend cutting fluid and thread-locking adhesive.
The tap in the kit is a different size than the bolt I’m repairing. Did I receive the wrong size?
This is a solid insert system (not wire coils). The tap matches the insert's external threads, requiring a larger hole. Once installed, the internal thread fits your original bolt perfectly. Not a mistake—just a heavy-duty solid-wall design.
What materials can this repair?
This kit repairs stripped threads in aluminum, cast iron, steel and most machinable metals – ideal for engine blocks, automotive parts and metal frames.
How is this thread repair different from a traditional Helicoil?
Kolvoii uses a solid stainless steel insert (not a wire coil). It requires drilling, counterboring, tapping, and installation — creating a stronger repair for high-stress or frequent disassembly. Solid inserts won't unwind or back out over time.
Is this safe to use on aluminum engine blocks or oil pans?
Yes. The stainless steel insert makes the repair stronger than the original aluminum threads. Ideal for high‑torque, high‑heat areas like cylinder heads, spark plug holes, oil pan drains, and transmission casings.