Guhring 9042870079380 Spiral Flute Tap 5/16-18 Unc Tin

Product Description

The GUHRING 9042870079380 is a spiral flute tap designed for blind hole threading in a wide range of ferrous and non-ferrous materials. It cuts a 5/16-18 UNC right-hand internal thread and carries a 2B class of fit, making it suitable for standard tolerance fastener applications. The tap is manufactured from high speed steel with a TiN coating to reduce friction and extend tool life. A 40-degree helix angle clears chips efficiently out of the blind hole. The modified bottoming chamfer allows threading close to the bottom of the hole. Overall length is 6 inches, with a tapping depth of 4 inches and a shank diameter of 0.318 inches.

This tap is intended for blind hole threading operations on production and maintenance work across metal fabrication, machine shops, and general industrial applications. It is well suited for use in aluminum and other non-ferrous metals, gray cast iron, malleable and spheroidal iron, stainless steel, and carbon and alloy steels. The three right-hand spiral flutes and 40-degree helix angle make it particularly effective when chip evacuation from a closed-bottom hole is a priority. It fits standard tap holders and collet chucks sized for a 0.318-inch shank with a 0.238-inch square drive.

Key Features

• 5/16-18 UNC thread form, 2B class of fit for standard tolerance internal threads
• Modified bottoming chamfer for threading close to the bottom of blind holes
• 40-degree right-hand helix for positive chip ejection in blind hole applications
• TiN coating reduces friction and improves wear resistance across extended production runs
• High speed steel construction handles a broad range of workpiece materials including stainless steel and cast iron
• 4-inch tapping depth in a 6-inch overall length tool

Compatibility

Designed for use in standard tap holders and machine spindles accepting a 0.318-inch shank diameter. Rated for aluminum and other non-ferrous metals, gray cast iron, malleable and spheroidal iron, stainless steel, and steel. Thread limit H4/H5 per Series 4287 specifications.

Installation Notes

This tap is installed and operated by machinists or toolroom technicians using a tapping machine, CNC machining center, or hand tap wrench. Always ensure the workpiece is securely fixtured and the pilot hole diameter is correct for a 5/16-18 UNC thread before starting. Confirm the tap holder square drive matches the 0.238-inch square size on this tap to avoid slippage or breakage. Use an appropriate cutting fluid for the workpiece material to extend tap life and maintain thread quality.