Baer Heli Coil Tap - Wire Thread Insert - Bottoming Tap (STI) - BSW - 7/8 x 9

The Baer Heli Coil Tap is the dedicated solution for impeccable thread repairs and reinforcements in British Standard Whitworth (BSW) applications. Designed as part of a complete Heli Coil insert system, this Bottoming Tap (STI) delivers precise, full-depth threads that are ready to accept a wire thread insert with confidence. Diameters and threads come together in a tool built to outlast typical repairs, making it a staple for any shop tackling worn or damaged holes.

Key features that matter in real-world use

• Bottoming geometry for full-depth threads. The tap reaches the bottom of blind holes, ensuring clean, complete engagement every time and preventing shallow, weak threads.
• BSW size compatibility. Specifically tailored for 7/8" diameter with 9 threads per inch, aligning with classic British thread standards and vintage machinery needs.
• Durable HSS construction. Crafted for longevity in tough metalworking environments, with a geometry that resists wear and maintains sharpness through repeated use.
• Wire thread insert readiness. Pairs seamlessly with Heli-Coil style inserts, giving you a reliable, reinforced thread that stands up to load and vibration.
• Precision you can trust. Ground and finished for tight tolerances, helping you avoid cross-threading and ensuring a snug, accurate fit for the insert.

Why this tap matters for your projects

Whether you’re restoring vintage equipment, repairing bolts for heavy machinery, or refurbishing aluminum or steel housings, the Baer Heli Coil Tap delivers dependable threads that restore original strength. A properly formed bottoming thread creates a solid foundation for the insert, which distributes load more evenly and reduces the risk of future stripping. In practice, this means faster repairs, fewer callbacks, and equipment that stays in service longer.

Practical use cases

• Repairing stripped or damaged BSW threads in engine blocks, housings, and linkages.
• Reinforcing critical mounting holes on vintage machinery where original threads have worn.
• Preparing holes for Heli-Coil inserts in repair jobs that demand reliable, pull-out resistant threads.
• Reestablishing accurate thread engagement in cast iron, steel, and select aluminum components.

Tips for optimal results

• Use appropriate cutting oil or coolant to reduce friction and extend tap life during alignment and cutting.
• Ensure the hole is drilled to the correct size and perpendicular to the surface before tapping for best results.
• Clean chips frequently to maintain thread integrity and prevent tool binding.
• After tapping, inspect the depth to confirm full-depth engagement before installing the Heli-Coil insert.

The Baer Heli Coil Tap — Wire Thread Insert, Bottoming Tap (STI), in 7/8 x 9 BSW — is your go-to tool when you need dependable, long-lasting internal threads that perform under load. Built for durability, precision, and real-world repair scenarios, it helps you restore functionality quickly and move on to your next project with confidence.