Osg 1430900 Spiral Flute Tap 3/8-16 Unc Bottoming Hss

Product Description

The OSG 1430900 is a spiral flute bottoming tap designed to cut 3/8-16 UNC internal threads in a wide range of metals. With a 50-degree helix angle and 3 right-hand flutes, it evacuates chips upward out of the hole, making it well suited for blind-hole tapping where chip clearance is critical. The bottoming chamfer allows threading to within a few threads of the bottom of a hole. Manufactured from high-speed steel with a bright uncoated finish, this tap carries an H3 thread limit and produces 3B class of fit threads. It is a standard production tool used by machinists, maintenance technicians, and trade professionals in shop and field settings.

The 1430900 is rated for use in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. It is a solid choice for production tapping, maintenance repair, and toolroom work where a bottoming tap is needed to maximize thread depth in blind holes. The right-hand flute direction and 50-degree helix angle promote smooth cutting and reliable chip removal across these material types. This tap is sold individually and is appropriate for use in manual tap handles or CNC tapping cycles where bottom-of-hole thread engagement is required.

Key Features

• Bottoming chamfer allows threading close to the bottom of blind holes
• 50-degree helix angle promotes upward chip evacuation in blind-hole applications
• H3 thread limit produces 3B class of fit threads for standard tolerance applications
• High-speed steel construction provides durability across a broad range of workpiece materials
• Bright uncoated finish - no coating buildup that could affect thread tolerance
• Right-hand thread and flute direction; compatible with standard tapping setups
• Coolant-through feature not required; suitable for conventional flood or dry tapping

Compatibility

Designed for tapping 3/8-16 UNC blind holes in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. OSG Series 107 spiral flute tap line.

Installation Notes

Bottoming taps should be used as the final tap in a tapping sequence, after a taper or plug tap has already started the thread. Power down or disengage the spindle before changing taps. Use appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Always secure the workpiece firmly before tapping to prevent movement and thread misalignment.