Value Collection JY9975533 Extension Tap 5/16-18 Unc Hss

Product Description

The VALUE COLLECTION JY9975533 is a spiral point plug extension tap designed for cutting internal threads in through-hole applications. Built from high-speed steel, it cuts 5/16-18 UNC threads to an H3 tolerance limit with a 3B class of fit, making it suitable for standard fastener clearances in general machining work. The spiral point geometry pushes chips forward ahead of the tap rather than packing them in the flute, reducing the risk of chip clogging in through-holes. With a 6-inch overall length, this extension tap reaches into recessed bores and deep cavities that standard-length taps cannot access. Machinists, tool and die makers, and maintenance technicians install this tap in CNC machines, drill presses, or by hand with a tap wrench.

This extension tap is suited for threading through-holes in ferrous and non-ferrous metals, plastics, and similar machinable materials where a 5/16-18 UNC fastener is required. The extra overall length of 6 inches is especially useful in fixture work, engine component repair, and fabrication tasks where deep reach or clearance around obstructions is needed. Its 2-flute design works well in general-purpose production and maintenance threading operations.

Key Features

• Spiral point geometry drives chips forward, keeping the cutting zone clear in through-hole applications
• H3 thread limit with 3B class of fit for standard tolerance internal threads
• High-speed steel construction provides durability across a range of common workpiece materials
• 6-inch overall length for extended reach into deep or obstructed bores
• 2-flute design balances chip clearance and cutting edge strength
• Plug chamfer (3-5 thread lead) allows starting in a through-hole with moderate lead-in

Compatibility

Designed as an OEM-style threading tool for any application requiring 5/16-18 UNC internal threads in through-hole workpieces where standard tap length is insufficient.

Installation Notes

This tap is installed by machinists and maintenance technicians using a tap wrench, tapping head, or CNC rigid tapping setup. Ensure the workpiece is properly secured and the tap is aligned perpendicular to the entry surface before beginning. Use an appropriate cutting fluid for the workpiece material to extend tap life and improve thread quality. Never reverse a tap under load without backing off chips first, and do not force the tap if resistance increases unexpectedly, as high-speed steel is brittle under torsional overload.