Osg 2494503 Straight Flute Plug Tap 7/16-14 Unc

Product Description

The OSG 2494503 is a straight flute plug tap designed for cutting 7/16-14 UNC right-hand internal threads in aluminum and cast iron workpieces. Built from vanadium high-speed steel with a nitride coating, this tap delivers increased surface hardness and wear resistance compared to uncoated HSS tooling. It features 4 flutes with an H3 thread limit, providing controlled oversize tolerance suited for use with standard tapping lubricants and fixtures. The overall length is 3-5/32 inches with a thread length of 1-7/16 inches. Installed by machinists and maintenance technicians in production and repair environments, this tap is suited for through-hole and blind-hole applications where chip evacuation is manageable.

This tap is intended for machine tapping operations in aluminum and cast iron materials. The plug chamfer — typically 3 to 5 threads of lead — makes it suitable for both through holes and moderately deep blind holes where the chamfer can engage gradually. It fits standard tapping heads, CNC machining centers, and drill press setups that accept a shank diameter of 0.323 inches. The Series 240 designation identifies it within OSG's straight flute tap line for general-purpose threading applications.

Key Features

• 7/16-14 UNC thread form with right-hand direction and H3 thread limit for controlled tolerance
• Vanadium high-speed steel construction provides toughness and elevated heat resistance
• Nitride coating increases surface hardness and reduces friction during tapping
• 4-flute straight design suited for aluminum and cast iron materials
• Plug chamfer for versatile use in through holes and moderate-depth blind holes
• No coolant-through requirement — compatible with external flood or manual lubrication

Compatibility

Designed for machine tapping of 7/16-14 UNC threads in aluminum and cast iron workpieces. Compatible with standard tapping chucks and holders that accept a 0.323-inch shank diameter.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tapping head, CNC spindle, or drill press with a tapping attachment. Ensure the workpiece is securely fixtured and the spindle speed is set appropriate to the material and tap diameter before engaging. Apply a suitable cutting fluid or tapping compound to prolong tool life and improve thread finish. Inspect the tap for wear or chipping before each use and replace if the cutting edges are damaged.