Osg 1752101 Spiral Flute Tap 5-40 Unc Modified Bottoming

Product Description

The OSG 1752101 is a spiral flute tap designed for cutting right-hand internal threads to a 5-40 UNC specification in demanding materials. It features a modified bottoming chamfer, which allows threading closer to the bottom of a blind hole than a standard plug tap. Built from powdered metal and finished with a steam oxide coating, the 1752101 provides improved lubricity and corrosion resistance during tapping operations. With 2 flutes and a 15-degree right-hand helix angle, it efficiently evacuates chips upward, making it well suited for through-hole and shallow blind-hole applications. The tap holds an H2 thread limit and a 2B/3B class of fit, meeting common tolerance requirements for precision threaded assemblies.

This tap is intended for use in a range of difficult-to-machine materials including alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloys. It is sized for small-fastener work typical in aerospace, medical device, instrumentation, and precision mechanical assembly applications. A licensed machinist or toolroom technician would typically install and operate this tap using a tapping head, CNC machining center, or manual tap wrench. Coolant-through is not supported on this tool.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• Spiral flute geometry with 15-degree right-hand helix angle for upward chip evacuation
• Powdered metal construction for increased wear resistance in tough alloys
• Steam oxide coating reduces friction and improves tool life in dry or minimally lubricated tapping
• H2 thread limit with 2B/3B class of fit for standard precision tolerance requirements
• Right-hand thread direction, 5-40 UNC, 40 threads per inch

Compatibility

Designed for tapping 5-40 UNC threads in alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Compatible with standard tap holders and chucks sized for a 0.141-inch shank diameter.

Installation Notes

This tap should be installed and operated by a qualified machinist or toolroom professional familiar with small-diameter tapping procedures. Always ensure the workpiece is securely fixtured and the spindle or tap wrench is properly aligned before beginning the threading operation. Use an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and maintain thread quality. Do not exceed the recommended speed range for the workpiece material and tap size, and never reverse a broken tap without first relieving cutting pressure.