Osg 1101701508 Spiral Point Tap 1/2-20 Unf Ticn Hss

Product Description

The OSG 1101701508 is a spiral point plug tap designed for threading 1/2-20 UNF right-hand internal threads in production and maintenance applications. Built from Vanadium High Speed Steel (HSS-E) and finished with a TiCN (Titanium Carbonitride) coating, this tap delivers improved wear resistance and lubricity compared to uncoated tooling. It features 3 flutes with a plug chamfer and carries an H3 thread limit to a 3B class of fit. Overall length is 3.937 inches with a thread length of 0.921 inches and a shank diameter of 0.367 inches. Machinists, toolroom technicians, and maintenance mechanics use this tap in both CNC and hand-tapping setups.

This tap is suited for through-hole threading in a wide range of ferrous and non-ferrous workpiece materials. Rated material applications include aluminum, hardened steel, stainless steel, high-carbon steel, low-carbon steel, medium-carbon steel, alloy steel, die steel, and cast iron. The plug chamfer distributes cutting load across several lead threads, making it appropriate for through-hole work where chip evacuation is manageable. The spiral point geometry pushes chips ahead of the tap rather than packing them in the flutes, which reduces the risk of tap breakage in moderate-depth through holes.

Key Features

• Thread size 1/2-20 UNF right-hand, 3B class of fit to H3 thread limit
• Vanadium High Speed Steel (HSS-E) construction for toughness in ferrous and non-ferrous materials
• TiCN coating increases surface hardness and reduces built-up edge in difficult materials
• Spiral point geometry pushes chips forward, suited for through-hole applications
• Plug chamfer distributes cutting load across the lead threads
• Non-coolant-through design; standard external coolant or cutting fluid applies

Compatibility

Designed as an OEM-style replacement or direct tooling selection for 1/2-20 UNF through-hole tapping operations across standard tap holders, floating holders, and hand tap wrenches that accept a 0.367-inch shank diameter.

Installation Notes

This tap is installed by a machinist or toolroom technician using a tap holder, tapping head, or hand tap wrench sized for the 0.367-inch shank. Before tapping, confirm the pilot hole is drilled to the correct tap-drill diameter for 1/2-20 UNF and that the workpiece is properly fixtured. Apply a suitable cutting fluid or tapping compound for the workpiece material — TiCN-coated taps still benefit from lubrication, particularly in stainless and alloy steels. Never reverse a tap under load without confirming chip clearance; back the tap off periodically to break and clear chips when hand tapping.