Osg 1650500108 Spiral Flute Tap 4-40 Unc 2 Flute

Product Description

The OSG 1650500108 is a spiral flute tap designed for threading 4-40 UNC holes in a wide range of ferrous and non-ferrous materials. Built from powdered metal (grade PMT15) and coated with TiCN for extended tool life, this tap features a 45-degree right-hand helix and a modified bottoming chamfer that allows threading close to the bottom of blind holes. With a 2B class of fit and H2 thread limit, it produces threads that meet standard tolerance requirements for most mechanical assemblies. Licensed machinists and toolroom techs will find it suited for production and maintenance work alike.

This tap is intended for use in manual or CNC tapping operations on materials including alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, and stainless steel. The two-flute spiral design evacuates chips upward out of the hole, making it particularly effective in blind-hole applications where chip packing is a concern. It is sold individually and fits standard 4-40 UNC tap holders and drive adapters.

Key Features

• 45-degree right-hand spiral flute for efficient upward chip evacuation in blind holes
• TiCN coating resists heat and abrasion, extending tool life in harder materials
• Modified bottoming chamfer allows threading to near the bottom of blind holes
• Powdered metal construction (PMT15) provides uniform hardness and wear resistance
• H2 thread limit and 2B class of fit for standard-tolerance 4-40 UNC threads
• Right-hand thread direction compatible with conventional tapping setups

Compatibility

Designed for 4-40 UNC tapping in alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, and stainless steel. Compatible with standard tap holders and drive adapters sized for No. 4 machine screw taps.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician using a properly aligned tap holder or tapping head. Ensure the workpiece is securely fixtured and the spindle is aligned perpendicular to the tapped surface before starting. Apply appropriate cutting fluid for the workpiece material to reduce heat and extend tap life. Do not reverse the tap under power without confirming the tapping setup supports reversing operation.