Osg 1101601103 Spiral Point Tap 5/16-18 Unc Nitride Hss

Product Description

The OSG 1101601103 is a spiral point tap designed for threading 5/16-18 UNC holes in production and maintenance applications. It features a plug chamfer, three flutes, and a right-hand thread direction. The tap is manufactured from vanadium high-speed steel (HSS-E) with a nitride coating that reduces friction and improves wear resistance during cutting. With an H5 thread limit and a 2B class of fit, it produces threads suited to standard mechanical assemblies. Overall length is 3.677 inches, and the threaded portion measures 1.125 inches. It is part of OSG Series 11016.

This tap is well suited for threading aluminum and cast aluminum workpieces in machine shop, fabrication, and field maintenance settings. The spiral point design pushes chips forward ahead of the tap, making it effective in through-hole applications where chip evacuation is critical. It is used by machinists, maintenance mechanics, and metalworking tradespeople working with standard UNC fastener threads in lighter non-ferrous materials. The 0.318-inch shank diameter is compatible with standard tap holders and tapping chucks.

Key Features

• 5/16-18 UNC thread form with right-hand cutting direction
• Plug chamfer — 3 to 5 lead threads — suited for through-hole tapping
• 3 flutes with spiral point geometry for forward chip ejection
• Vanadium HSS-E construction for improved toughness and edge retention over standard HSS
• Nitride coating reduces surface friction and extends tool life in aluminum applications
• H5 thread limit with 2B class of fit for standard mechanical thread tolerances
• Coolant-through design: No — suitable for hand tapping and standard machine tapping

Compatibility

Rated for use in aluminum and cast aluminum. Designed as an OEM-specification spiral point tap for standard 5/16-18 UNC through-hole threading operations where a 2B class of fit is required.

Installation Notes

This tap is installed and operated by machinists or maintenance mechanics using a tapping machine, drill press, or CNC machining center with a tap holder, or by hand using a tap wrench. Ensure the workpiece is securely fixtured before tapping. Use a cutting fluid appropriate for the workpiece material — a sulfurized or aluminum-specific cutting oil is recommended for non-ferrous materials. Inspect tap for wear or chipping before each use; a damaged tap can seize in the hole and break, requiring extraction.