Osg 1135800 Straight Flute Tap 7/8-14 Unf Plug Hss

Product Description

The OSG 1135800 is a straight flute tap designed to cut 7/8-14 UNF right-hand internal threads in a range of ferrous and non-ferrous materials. Built from high-speed steel with a bright uncoated finish, it delivers consistent thread quality in applications where through-hole tapping is the standard approach. The plug chamfer configuration provides a balance between starting ease and full thread engagement, making it suitable for both through-holes and moderately deep blind holes. With an H4 thread limit, it holds tight tolerances required for a 3B class of fit. This tap is a production and maintenance tool used by machinists, tool and die technicians, and industrial maintenance professionals.

This tap is suited for tapping operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Its straight flute geometry works well in through-hole applications and in materials that produce short, brittle chips. It is commonly used in machine shop production environments, maintenance and repair operations, and manual tapping setups. The 4-flute design provides stability and thread accuracy across this range of material types.

Key Features

• 7/8-14 UNF thread form with right-hand cutting direction
• Plug chamfer for easy starting in through-holes and moderate-depth blind holes
• H4 thread limit for precise 3B class of fit tolerance
• High-speed steel construction for durability across a broad material range
• Bright uncoated finish suitable for general-purpose tapping applications
• 4-flute straight design provides chip stability in short-chipping materials
• No coolant-through feature - compatible with standard flood or manual lubrication

Compatibility

Designed for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Part of the OSG Series 101 straight flute tap line.

Installation Notes

Install in a tapping head, drill press, CNC machining center, or manual tap wrench rated for the torque requirements of the workpiece material. Ensure the workpiece is securely fixtured and the tap is properly aligned to the pre-drilled hole before engagement. Always apply appropriate cutting fluid for the material being tapped. Power down or disengage the machine spindle before changing or inspecting the tap.