Osg 1301403201 Spiral Flute Tap 1-1/4-12 Unf 5 Flutes

Product Description

The OSG 1301403201 is a spiral flute tap designed to cut 1-1/4-12 UNF internal threads in a wide range of ferrous materials. Built from vanadium high-speed steel and finished with a steam oxide coating, it delivers controlled chip evacuation in blind-hole applications where modified bottoming geometry is required. The 5-flute spiral configuration pulls chips up and out of the hole during the tapping cycle, reducing the risk of chip packing and tap breakage. This is a production-grade hand or machine tap suited for tool rooms, machining centers, and maintenance shops performing precision thread work in steel and iron components.

This tap is intended for threading in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. The modified bottoming chamfer allows the tap to start threads close to the bottom of a blind hole while still maintaining adequate chamfer length for proper thread form. The 2B class of fit meets standard tolerance requirements for most general mechanical assemblies and fastener interfaces. It is used in both CNC tapping operations and manual tap-wrench applications where consistent UNF thread quality is needed across production or repair work.

Key Features

• 1-1/4-12 UNF thread form with right-hand thread direction and 2B class of fit
• 5 right-hand spiral flutes with a 15-degree helix angle for effective chip lift in blind holes
• Modified bottoming chamfer for threading close to the bottom of blind bores
• Vanadium high-speed steel construction for improved wear resistance in tough ferrous materials
• Steam oxide coating reduces friction and provides light corrosion protection during storage and use
• No coolant-through design; suitable for external flood or manual lubrication setups

Compatibility

Designed for tapping alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. Belongs to OSG Series 13014. Confirm machine spindle capacity and tap holder collet size against the 0.323-inch shank diameter before installation.

Installation Notes

Tapping operations should be performed by a machinist or tooling specialist familiar with speed and feed selection for HSS taps in the target material. Ensure the workpiece is securely fixtured and the tap is properly aligned to the pre-drilled hole before engaging the spindle. Apply a suitable tapping fluid or cutting oil for the material being threaded; dry tapping in steel will shorten tool life. Inspect the tap for wear or chipping between uses, as a damaged tap can strip threads or break in the hole.