Osg 1720201 Spiral Flute Tap 3/8-16 Unc 2B Powdered Metal

Product Description

The OSG 1720201 is a spiral flute tap designed for threading 3/8-16 UNC holes in difficult-to-machine materials. It features a modified bottoming chamfer, 3 right-hand spiral flutes with a 10-degree helix angle, and a 2B class of fit. The powdered metal construction with a steam oxide coating improves lubricity and reduces galling during the tapping cycle. With an overall length of 2-15/16 inches and a thread limit of H5, this tap is suited for applications where tight thread tolerance and chip evacuation are both critical. Licensed machinists and CNC operators in production and toolroom environments are the primary users.

The OSG 1720201 is specifically engineered for use in stainless steel, hardened steel, titanium, and high-nickel alloys — materials known for work hardening and built-up edge on cutting tools. The spiral flute geometry pulls chips up and out of the hole, making it effective in blind-hole applications where chip packing is a concern. It is well suited for both CNC machining centers and manual tapping operations where consistent thread form and tool life are required in demanding production environments.

Key Features

• 3/8-16 UNC thread form with 2B class of fit for standard fastener engagement
• Modified bottoming chamfer allows threading closer to the bottom of a blind hole
• 3-flute spiral design with 10-degree right-hand helix for upward chip evacuation
• Powdered metal substrate provides increased wear resistance over standard HSS
• Steam oxide coating reduces friction and improves performance in difficult alloys
• H5 thread limit maintains tolerance control in stainless steel and high-nickel alloys

Compatibility

Designed for threading stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Part of the OSG Series 313NI tap line, optimized for nickel-alloy and exotic-material applications.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator. Ensure the workpiece is securely fixtured and the spindle is aligned with the pilot hole before starting the tap. Use an appropriate tapping fluid or cutting oil rated for stainless steel or titanium when running this tool manually; verify coolant compatibility when running on a machining center. Inspect the tap for wear or chipping before each use — powdered metal tooling is more brittle than standard HSS and should not be used in impact or hand-tapping scenarios without proper support.