The OSG BSF Spiral Flute Threading Tap is a precision tool designed for blind-hole threading in metalworking. Built for professionals who demand accuracy and durability, it delivers high-quality, reliable threads with extended tool life.

• Thread type: BSF (British Standard Fine) spiral-flute design optimized for efficient cutting and chip evacuation in blind holes.
• Material: HSS-E cobalt alloy for increased hardness and heat resistance during demanding tapping operations.
• Coating: Steam oxide finish provides wear and corrosion protection, improving longevity in tough machining environments.
• Size/Thread: 7/16" diameter with 18 TPI (7/16 x 18 BSF) for precise, compatible fastener threading.
• Flute geometry: Spiral flute geometry enhances chip removal, reducing binding and allowing deeper hole tapping with consistent results.
• Brand technology: OSG’s advanced threading technology delivers clean threads and dependable performance across production and repair tasks.

With this tap, you can achieve accurate, repeatable BSF threads in blind holes, even in challenging materials. The combination of HSS-E cobalt, steam oxide coating, and a spiral flute design minimizes wear, manages heat, and channels chips away from the cutting edge—keeping your operation smooth and efficient from start to finish. Ideal for maintenance, fabrication, and precision assemblies where inside-out threading is required and reliability matters.