The Baer Heli Coil Tap - Wire Thread Insert - Bottoming Tap (STI) - UNF - 5/8 x 18 is the precise, durable tool you reach for when threads need repair, reinforcement, or restoration with Heli-Coil inserts. Built for professional reliability, this bottoming tap delivers clean, accurate thread formation that stands up to demanding applications and repeated use.

• Bottoming design for full-depth engagement—reaches the very bottom of blind holes to ensure each insert threads in securely, maximizing strength and longevity.
• HSS-G heat-treated construction—crafted from high-speed steel and hardened for wear resistance, delivering consistent performance across steel, cast iron, and aluminum components.
• UNF compatibility, 5/8 x 18—precisely engineered for standard UNF threads, making it a dependable choice for automotive, industrial, and mechanical repairs.
• Optimized for Heli-Coil inserts—designed to work in harmony with wire thread inserts, ensuring the insert coils bite cleanly into accurately formed threads for reliable load transfer and torque tolerance.
• Consistent, burr-free results—tightly controlled geometry and flute design minimize chip buildup and reduce the risk of cross-threading during installation.

Ideal use cases

Whether you’re repairing stripped threads on engine blocks, transmission housings, or machinery housings, this tap provides the precision needed for a dependable insert installation. It’s equally suited for fabrication shops, maintenance teams, and hobbyists tackling metalwork projects where strong, vibration-resistant threads are essential.

Practical guidance for best results

• Use a light cutting lubricant and steady, straight pressure to maintain thread integrity.
• Align the tap carefully with the hole to prevent cross-threading and ensure the bottoming section engages correctly.
• Tap only to the depth required for the Heli-Coil insert you’re using; avoid over-tapping to protect surrounding material.
• Pair with proper Heli-Coil inserts and tang removal tools to complete a secure, lasting repair.

Why choose this tap? It’s not just about cutting threads—it's about enabling durable repairs that restore original strength. The Baer Heli Coil Tap is purpose-built to work with insert systems, delivering repeatable results you can trust in mission-critical components and everyday hardware alike.