Osg 1302000901 Spiral Flute Tap 3/8-16 Unc Hss

Product Description

The OSG 1302000901 is a spiral flute plug tap designed for cutting 3/8-16 UNC internal threads in a wide range of ferrous and non-ferrous metals. Built from high-speed steel (HSS) with a steam oxide coating, it runs a 45-degree helix angle that evacuates chips upward out of the hole — the defining advantage of spiral flute geometry in blind-hole applications. The plug chamfer (3-5 threads) provides a balanced lead-in suitable for most through-hole and shallow blind-hole threading operations. Thread tolerance is H3, producing a 3B class of fit. Overall length is 2.938 inches with a shank diameter of 0.381 inches.

This tap is suited for general-purpose threading work in machine shops, maintenance facilities, and production environments. It performs in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The right-hand spiral flute design makes it compatible with standard CNC machining centers, knee mills, drill presses with tapping attachments, and hand tapping applications where the helix assists chip clearance. It carries no coolant-through capability, so flood or mist coolant is applied externally at the cutting zone.

Key Features

• 45-degree right-hand helix evacuates chips upward, ideal for blind-hole threading
• Plug chamfer with 3B class of fit and H3 thread limit for standard tolerance internal threads
• High-speed steel construction withstands moderate cutting speeds across a broad material range
• Steam oxide coating reduces friction and provides light corrosion resistance during storage and cutting
• Thread length of 0.5 inches and neck length of 1.251 inches suit typical fastener-depth applications
• No coolant-through requirement simplifies use on equipment without internal coolant delivery

Compatibility

Designed for cutting 3/8-16 UNC right-hand internal threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Fits standard 3/8-inch tap holders and collet chucks sized for a 0.381-inch shank diameter.

Installation Notes

Installation is performed by licensed machinists or qualified maintenance technicians using a tap wrench, tapping head, or rigid CNC tapping cycle. Ensure the workpiece is securely fixtured and the tap is aligned perpendicular to the drilled hole before engagement. Always use a cutting fluid appropriate for the workpiece material to extend tap life and improve thread finish. Follow applicable shop safety procedures and de-energize any powered equipment before hand-tapping in place.