Osg 1135700 Straight Flute Tap 7/8-14 Unf 4 Flute Taper

Product Description

The OSG 1135700 is a straight flute tap designed for cutting 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 runs a taper chamfer and a 3B class of fit with an H4 thread limit for consistent, close-tolerance results. Overall length is 4-11/16 inches, thread length is 2-7/32 inches, and the part weighs 0.43 pounds. Four flutes provide adequate chip clearance for the materials this tap is rated to cut. It is suited for manual or machine tapping operations in job shop, maintenance, and production environments.

This tap is rated for use in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. The taper chamfer makes it well suited for starting threads from a through-hole or as the first tap in a three-tap sequence. It is a common choice for machinists, toolroom technicians, and maintenance mechanics working on inch-series UNF fastener applications in the 7/8-14 size range. The Series 101 designation identifies it within OSG standard product offerings for this configuration.

Key Features

• 7/8-14 UNF thread form with right-hand direction and 3B class of fit
• H4 thread limit for predictable tolerance control in production tapping
• Taper chamfer for easy thread entry and reduced starting torque
• High-speed steel construction handles steel, cast iron, and aluminum applications
• 4-flute straight flute geometry provides chip relief in through and blind-hole applications
• Bright/uncoated finish suitable for use with cutting fluids across a broad material range

Compatibility

Designed as an OEM-style replacement or direct tooling option for 7/8-14 UNF tapping applications in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. Coolant-through is not supported on this tap.

Installation Notes

This tap should be installed and used by machinists or qualified toolroom personnel familiar with tapping operations and cutting fluid practices. Ensure the workpiece is securely clamped and that the correct drill size for a 7/8-14 UNF thread has been used prior to tapping. Apply an appropriate cutting fluid for the material being tapped, and reverse periodically to break chips when tapping blind holes. Follow applicable shop safety and machine guarding procedures when using in a power tapping or CNC environment.