Osg 1725101 Spiral Point Tap 9/16-18 Unf 3 Flute

Product Description

The OSG 1725101 is a spiral point plug tap designed for threading 9/16-18 UNF right-hand internal threads in production and maintenance machining environments. Built from vanadium high-speed steel (HSS-E) with a steam oxide coating, this tap offers improved lubricity and corrosion resistance compared to uncoated tooling. The plug chamfer distributes cutting load across the first few threads, making it well suited for through-hole tapping operations. With a 3-flute spiral point geometry, the tap pushes chips forward ahead of the cut rather than packing them into the flute, supporting cleaner thread formation at moderate to higher feed rates. Overall length is 3.594 inches with a thread length of 1.27 inches.

This tap is intended for use in ferrous materials including low-carbon steel, medium-carbon steel, hardened steel, and stainless steel. The H3 thread limit provides a controlled oversize tolerance suitable for standard UNF fits. Typical applications include threading through holes in structural components, fastener-receiving bores, and hydraulic or pneumatic manifold work where UNF fine-thread engagement is required. Machinists in industrial, tool-and-die, maintenance, and fabrication shops are the primary users. It is not configured for coolant-through delivery.

Key Features

• 9/16-18 UNF thread form, right-hand, H3 thread limit for controlled tolerance
• Vanadium high-speed steel (HSS-E) construction for improved toughness and wear resistance over standard HSS
• Steam oxide coating reduces friction and improves chip flow during cutting
• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• Plug chamfer distributes entry load across multiple leading threads
• 3 flutes provide good chip clearance in ferrous materials

Compatibility

Designed for tapping 9/16-18 UNF through holes in low-carbon steel, medium-carbon steel, hardened steel, and stainless steel workpieces. Compatible with standard tap holders and chucks accepting a 0.429-inch shank diameter.

Installation Notes

This tap should be installed by a qualified machinist in a properly aligned tap holder or CNC spindle to prevent thread distortion or tool breakage. Secure the workpiece firmly before beginning the tapping cycle and confirm through-hole clearance before driving the tap to avoid bottoming. Apply cutting fluid appropriate for the workpiece material, particularly when tapping stainless steel or hardened steel. Inspect the tap for wear or chipping before each use and replace if cutting edges show degradation.