Osg 1305710208 Spiral Flute Tap 4-40 Unc Ticn Coated

Product Description

The OSG 1305710208 is a spiral flute tap designed for cutting 4-40 UNC internal threads in challenging materials. It features a modified bottoming chamfer, three right-hand flutes with a 10-degree helix angle, and a TICN (titanium carbonitride) coating over a powdered metal substrate. The spiral flute geometry evacuates chips up and out of the hole, making it well suited for blind-hole tapping applications. With an overall length of 1.875 inches and an H2 thread limit, it holds tight tolerances for 2B and 3B class-of-fit requirements. Licensed machinists, tool-and-die makers, and CNC operators are the primary users of this tap.

This tap is built for use in materials that demand both coating hardness and substrate toughness. Rated material applications include alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloys. Its compact 4-40 UNC thread size makes it common in precision assemblies, instrument hardware, and small-component manufacturing where fine threads and close tolerances are critical. It is equally at home in manual tapping fixtures and CNC machining centers equipped for rigid or semi-rigid tapping cycles.

Key Features

• Spiral flute design evacuates chips upward, reducing packing in blind holes
• TICN coating increases surface hardness and lubricity for extended tool life in abrasive and hard materials
• Powdered metal construction provides a uniform, fine-grain substrate with high wear resistance
• Modified bottoming chamfer allows threading close to the bottom of a blind hole
• H2 thread limit holds consistent 2B and 3B class-of-fit tolerances
• Right-hand thread and right-hand flute direction — compatible with standard spindle rotation

Compatibility

Designed for cutting 4-40 UNC threads in alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloys. Part of the OSG Series 313TI tap line.

Installation Notes

Tapping operations should be performed by a qualified machinist following established speeds and feeds for the workpiece material and tap size. Ensure the workpiece is securely fixtured and the tap is properly aligned to the pilot hole before engagement. Always use an appropriate tapping fluid or cutting oil for the material being threaded. Inspect the tap for wear or chipping before each use; a damaged tap can cause thread failure or tap breakage in the hole.