Osg 1430800 Spiral Flute Tap 3/8-16 Unc Hss Bright

Product Description

The OSG 1430800 is a spiral flute tap designed for cutting internal 3/8-16 UNC threads in a wide range of metallic workpieces. Built from high-speed steel with a bright uncoated finish, it features three right-hand flutes at a 50-degree helix angle, which efficiently evacuates chips upward out of the hole during tapping. The plug chamfer (3-5 thread lead) makes it suited for through-hole applications. Thread limit is H3, and the class of fit is 3B, providing a standard tolerance range appropriate for most general-purpose fastener assemblies. Overall length is 2.938 inches with a shank diameter of 0.381 inches.

This tap is intended for use in machine tapping and hand tapping operations across production and maintenance environments. The spiral flute geometry is particularly effective in blind and through holes where chip clearance is a concern. Material compatibility includes aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel, making it a versatile tool for job shops, maintenance facilities, and manufacturing operations that work across multiple material types.

Key Features

• 3/8-16 UNC thread form, 3B class of fit, H3 thread limit for standard tolerance fastener work
• 50-degree right-hand spiral flute geometry for efficient chip evacuation in blind and through holes
• Plug chamfer with 3-5 thread lead - suited for through-hole and clearance-start tapping
• High-speed steel construction provides durability across a broad range of workpiece materials
• Bright uncoated finish - compatible with cutting oils and standard tapping fluids without coating interaction
• No coolant-through requirement; standard flood or brush-applied cutting fluid is sufficient

Compatibility

Compatible with aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces as stated by the manufacturer. Designed for use in standard 3/8-16 UNC tapping applications requiring a 3B class of fit.

Installation Notes

Installation should be performed by a machinist or qualified technician using a tap wrench, tapping head, or CNC/manual machine tool with appropriate speed and feed settings for the workpiece material. Ensure the workpiece is securely fixtured and the tap is aligned perpendicular to the drilled hole before beginning the cut. Apply a suitable cutting fluid or tapping compound appropriate for the workpiece material to extend tool life and improve thread finish. Do not force a seized tap - reverse the tap incrementally to break chips before continuing.