Osg 5003402 Spiral Flute Tap 1/4-20 Unc Plug 2B Hss

Product Description

The OSG 5003402 is a spiral flute tap designed to cut 1/4-20 UNC internal threads in a wide range of ferrous and non-ferrous materials. It features 3 right-hand flutes with a 50-degree helix angle, which directs chips up and out of the hole during blind-hole tapping operations. The plug chamfer provides a gradual thread lead-in over several threads, making it well-suited for through-holes and moderately deep blind holes. Ground to an H5 thread limit, it holds a 2B class of fit - the standard tolerance for general-purpose inch-series threaded fastener applications. The elektraLUBE coating reduces friction and built-up edge, extending tool life across production and maintenance work.

This tap is intended for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. At 2.5 inches overall length, it is sized for standard hand-tapping and machine-tapping setups in both job shop and maintenance environments. Machinists, tool and die makers, and maintenance mechanics commonly reach for this size when threading 1/4-20 holes in machine frames, fixtures, fastener blocks, and fabricated assemblies. It is sold individually and is suited for both production runs and one-off repair work.

Key Features

• 1/4-20 UNC thread form with right-hand thread direction
• 3 spiral flutes at 50-degree helix angle for efficient chip evacuation in blind holes
• Plug chamfer for gradual thread engagement over multiple threads
• H5 thread limit ground to 2B class of fit for standard general-purpose tolerance
• High-speed steel construction for toughness across a broad range of workpiece materials
• elektraLUBE coating reduces friction and improves tool life without additional lubrication in many applications
• No coolant-through requirement - compatible with standard tapping fluid or dry tapping setups

Compatibility

Rated for use in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. OSG Series 107 spiral flute tap line.

Installation Notes

Tap installation should be performed by a qualified machinist or maintenance mechanic using a properly sized tap wrench or CNC/manual tapping attachment. Ensure the workpiece is securely fixtured and that the tap is started perpendicular to the hole to avoid thread misalignment or breakage. Apply a suitable tapping fluid or cutting oil for steel workpieces; dry or mist tapping may be acceptable for aluminum depending on the setup. Remove the tap periodically to clear chips when working in deeper blind holes, even with spiral flute geometry.