Baer Heli Coil Tap - Wire Thread Insert - Bottoming Tap (STI) - UNF - 1.1/8 x 12

The Baer Heli Coil Tap is the go-to tool for impeccable thread repairs and reinforcements. Designed for UNF threads and built around the needs of professional shop work, this bottoming tap (STI) ensures clean, accurate tapping every time, so you can install wire thread inserts with confidence.

Key features that set this Heli Coil Tap apart:

• Bottoming tap geometry delivers full-depth threads in blind holes, creating a solid foundation for reliable insert engagement and long-term performance.
• UNF compatibility—1-1/8 inch diameter with 12 threads per inch provides a precise, high-strength thread for demanding applications.
• Wire thread insert readiness—crafted to work seamlessly with Heli-Coil style inserts, restoring damaged threads or reinforcing soft metals for renewed strength.
• Durable construction—engineered for durability and repeated use in metalworking environments, from automotive repairs to machinery maintenance.
• Versatile application—ideal for repairing stripped holes, rebuilding cast or machined parts, and creating dependable threads in a variety of projects.

Why this matters in practice: when a hole’s threads are damaged, a reliable repair isn’t optional—it’s essential. This tap helps you cut precise, repeatable threads that match inserts perfectly, reducing the risk of pull-out, cross-threading, or premature wear. The result is a repair that feels as solid as the original and stands up to real-world use, whether you’re restoring a vintage engine, servicing precision equipment, or fabricating a sturdy, maintenance-friendly assembly.

Practical use cases include:

• Repairing stripped threads in engines, transmissions, and structural components where inserts are preferred for durability.
• Reinforcing soft metals like aluminum to handle frequent disassembly and reassembly without losing grip.
• Preparing holes for Heli-Coil inserts in manufacturing or repair work that demands repeatable, high-strength threads.
• Maintenance work on equipment where a dependable, wear-resistant thread is critical for performance.

Tip from the field: pair this bottoming tap with appropriate cutting lubricant and ensure the tap remains perpendicular to the work surface during cutting to achieve the best thread form and insert seating. For best results, use a drill chart to confirm the proper drill size for your UNF 1-1/8 x 12 hole size before tapping.