Osg 1406408 Spiral Flute Tap 4-40 Unc Hss Ticn

Product Description

The OSG 1406408 is a spiral flute plug tap designed for cutting 4-40 UNC internal threads in a range of metals commonly encountered in machining and fabrication work. Built from high-speed steel (HSS) with a titanium carbonitride (TiCN) coating, it delivers extended tool life in abrasive and harder materials compared to uncoated HSS taps. The plug chamfer distributes cutting load gradually across the lead threads, making it well suited for through-hole tapping. With a 50-degree helix angle, the spiral flute design efficiently evacuates chips upward out of the hole, reducing chip packing in short or blind hole applications. This tap is used by machinists, tool and die makers, and maintenance technicians.

The OSG 1406408 is appropriate for tapping 4-40 UNC threads in both production and maintenance settings. Its 2B and 3B class-of-fit compatibility gives it versatility across standard commercial and precision thread fit requirements. The right-hand spiral flute and right-hand thread direction are the conventional configuration for standard CNC and manual tapping operations on vertical or horizontal machines. Typical materials for this tap include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel.

Key Features

• 4-40 UNC thread form with right-hand thread direction and H2 thread limit
• 50-degree helix angle spiral flute for effective chip evacuation in through and shallow blind holes
• TiCN coating extends tool life in abrasive and harder materials versus uncoated HSS
• Plug chamfer for gradual cutting load distribution in through-hole and entry tapping
• 2B and 3B class-of-fit compatibility for commercial and precision thread fit requirements
• No coolant-through design; suitable for standard hand or machine tapping with applied cutting fluid

Compatibility

Designed for cutting 4-40 UNC internal threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Compatible with standard tap holders and collets sized for a 0.141-inch shank diameter.

Installation Notes

This tap should be installed by a qualified machinist or maintenance technician familiar with tapping procedures and toolholding practices. Always ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled pilot hole before beginning the threading cycle. Apply an appropriate cutting fluid for the workpiece material to reduce friction and improve thread finish. Inspect the tap for wear or chipping before each use, and never back-drive a tap under power without confirming the machine cycle is designed for reversal.