Osg 1124102 Straight Flute Tap 5/8-18 Unf Bottoming Hss

Product Description

The OSG 1124102 is a straight flute bottoming tap designed for threading 5/8-18 UNF right-hand threads in a wide range of metals. Built from high-speed steel, it delivers consistent performance in production and maintenance tapping operations. The bottoming chamfer allows threading close to the bottom of blind holes where spiral flute or plug taps cannot reach. With a thread limit of H3 and a Class 3B fit, this tap produces close-tolerance threads suited for precision fastener assemblies. It features 4 flutes and an overall length of 3-13/16 inches with a thread length of 1-13/16 inches. Machinists, tool-and-die makers, and maintenance mechanics are the typical users.

This tap is suited for tapping operations in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It is appropriate for both manual hand-tapping setups and machine tapping where a straight flute geometry is preferred. The straight flute design works best in shorter-chipping materials where chip evacuation does not require a spiral flute. It is a fit for job-shop, production floor, and field maintenance environments where UNF thread standards apply.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 5/8-18 UNF thread size, right-hand thread direction
• High-speed steel construction for durability across a range of workpiece metals
• 4 straight flutes suited for short-chipping materials
• H3 thread limit with Class 3B fit for close-tolerance threaded assemblies
• No coolant-through design - compatible with standard cutting fluid application

Compatibility

Designed for tapping 5/8-18 UNF threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Part of OSG Series 101.

Installation Notes

This tap is installed by machinists or maintenance mechanics using a standard tap wrench, tapping head, or machine spindle rated for the appropriate torque. Secure the workpiece before tapping and ensure the tap is aligned perpendicular to the hole to prevent tap breakage. Apply a suitable cutting fluid for the workpiece material before and during tapping. Never force a tap in a bottomed hole - back off periodically to clear chips and prevent binding.