Osg 1593800 Spiral Point Tap 3/4-10 Unc Plug Hss

Product Description

The OSG 1593800 is a spiral point plug tap designed for threading 3/4-10 UNC through-holes in a range of ferrous and non-ferrous materials. Manufactured from high-speed steel with a bright finish, it features a 3-flute, right-hand spiral point geometry that pushes chips ahead of the cut rather than packing them in the flute. This action keeps the cutting zone clear and supports consistent thread quality at production feed rates. The plug chamfer provides a gradual lead-in, making it suitable for through-hole applications where full thread depth is required before the hole exits. With an H11 thread limit and a nominal 0.0050-inch oversize grind, it is engineered to produce threads at the higher end of the tolerance range to account for spring-back in tougher alloys. Licensed machinists, toolroom technicians, and maintenance mechanics are the primary users.

This tap is suited for through-hole threading operations in both manual and CNC tapping applications. Its material compatibility list covers a broad range of stock commonly encountered in production and repair environments, including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The 3-flute configuration and spiral point geometry are particularly effective in materials where chip evacuation forward through the hole is practical. It fits standard 3/4-inch tap holder collets and is appropriate for job shop, maintenance, and light production work.

Key Features

• Spiral point geometry pushes chips ahead of the tap for clean through-hole threading
• Plug chamfer for gradual lead-in in through-hole applications
• H11 thread limit with 0.0050-inch oversize grind for consistent tolerance control
• High-speed steel construction handles a wide range of ferrous and non-ferrous materials
• Bright finish with no coating — suitable for use with standard tapping fluids
• Right-hand thread direction, 3/4-10 UNC

Compatibility

Compatible with aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces. Designed for 3/4-10 UNC through-hole threading in standard tap holders accepting 3/4-inch shank tooling.

Installation Notes

This tap should be installed by a qualified machinist or toolroom technician familiar with tapping operations and speed-and-feed selection for high-speed steel tooling. Always secure the workpiece and verify spindle alignment before beginning the tapping cycle. Use an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread finish. For CNC applications, confirm rigid vs. floating tap holder requirements and set feed rates consistent with HSS tap recommendations for the specific material being threaded.