Osg 1230402 Spiral Point Tap 1/4-28 Unf Plug Hss

Product Description

The OSG 1230402 is a spiral point tap designed for cutting 1/4-28 UNF internal threads in a wide range of ferrous and non-ferrous materials. Manufactured from high-speed steel with an elektraLUBE coating, this plug-chamfer tap pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping applications. The 2-flute design provides efficient chip evacuation and reduced torque. It carries a 3B class of fit and an H3 thread limit, producing threads that meet standard tolerance requirements for precision fastener assemblies. Right-hand thread direction, 1 inch thread length, and a Series 105 designation complete the specification profile.

This tap is intended for through-hole tapping on the shop floor, maintenance bench, or in the field wherever 1/4-28 UNF threads are required. Its material compatibility range includes aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel, making it a practical single-tool choice across a broad cross-section of industrial and mechanical assembly tasks. Machinists, millwrights, and maintenance technicians working with threaded fastener repairs or new fabrication will find this tap appropriate for hand tapping or machine tapping operations.

Key Features

• 1/4-28 UNF thread size with plug chamfer for through-hole starting and chip-forward cutting action
• High-speed steel construction provides durability across a wide range of workpiece materials
• elektraLUBE coating reduces friction and extends tool life in dry or minimal-lubricant tapping applications
• H3 thread limit and 3B class of fit for standard precision thread production
• 2-flute geometry supports efficient chip evacuation and lower cutting torque
• Right-hand thread direction with 1 inch thread length

Compatibility

Compatible with aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces. Suitable for hand tapping or machine tapping setups requiring a 1/4-28 UNF plug tap with H3 thread limit.

Installation Notes

Secure the workpiece firmly before tapping and ensure the tap is aligned perpendicular to the drilled hole to prevent thread distortion or tap breakage. Even with an elektraLUBE coating, applying a compatible cutting fluid is recommended when tapping harder ferrous materials to extend tool life. Use a calibrated tap wrench or tapping head matched to the tap shank size. Follow applicable shop safety protocols and consult material-specific feeds and speeds references for machine tapping operations.