Osg 1123701 Straight Flute Tap 5/8-11 Unc Hss Oxide

Product Description

The OSG 1123701 is a straight flute tap designed for cutting internal threads in a range of ferrous and non-ferrous materials. It produces a 5/8-11 UNC right-hand thread to a 3B class of fit with an H3 thread limit, making it suitable for applications requiring consistent, tolerance-controlled threads. The plug chamfer — with 3 to 5 threads of lead — allows the tap to start in a through-hole or a deep blind hole with adequate clearance. At 3-13/16 inches overall length and a 1-13/16 inch thread length, this tap fits standard tap holders and machine spindles used by machinists and maintenance trades alike. The 4-flute straight design provides good chip control in the short, broken chips typical of cast iron and carbon steels.

This tap is intended for use in through-holes and blind holes where chips can be cleared manually or with cutting fluid. Material applications include aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. The oxide coating provides a mild lubricity advantage and light corrosion resistance during storage and use. It is well-suited for manual tapping, drill press setups, and light CNC tapping operations in job shop, maintenance, and production environments. Individual packaging makes it a practical single-unit replacement for tool crib stock.

Key Features

• 5/8-11 UNC thread form with right-hand direction and 3B class of fit
• H3 thread limit for controlled tolerance in standard through-hole and blind-hole applications
• Plug chamfer provides 3-5 thread lead for easy starting and versatile hole type usage
• 4 straight flutes promote chip evacuation in short-chipping materials
• High-speed steel construction with oxide coating for durability and light lubricity
• Compatible with aluminum, cast iron, and low- to high-carbon steel workpieces

Compatibility

Designed for use in standard tap holders, T-handle wrenches, and machine spindles accepting a 0.48-inch shank diameter. Suitable for tapping aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel per OSG Series 101 specifications.

Installation Notes

Secure the workpiece and ensure the starter hole is drilled to the correct tap drill diameter for a 5/8-11 UNC thread before tapping. Apply an appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. When tapping by hand, use a calibrated tap wrench and back off periodically to break chips. When used in a machine setup, verify spindle speed and feed rate are appropriate for the material and tap diameter to avoid tap breakage.