Osg 1400103701 Thread Forming Tap 3-48 Unc Modified Bottoming

Product Description

The OSG 1400103701 is a thread forming tap designed for cold-form tapping in blind hole applications. Unlike cutting taps, this tool displaces material rather than cutting it, producing strong, burnished threads with no chips to clear. It is ground from cobalt high-speed steel for improved heat and wear resistance and carries a steam oxide coating that reduces friction and aids in lubrication retention during tapping. Sized for 3-48 UNC threads with a modified bottoming chamfer of 2 to 2.5 threads, it is suited for machinists, tool and die makers, and maintenance technicians working on precision threaded assemblies.

This tap is built for blind hole threading in a wide range of materials, including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The modified bottoming chamfer allows the tap to thread closer to the bottom of a blind hole than a standard plug chamfer, making it useful in tight-tolerance assemblies where thread engagement depth is critical. It is part of the OSG HY-PRO NRT series and is intended for use in both manual and machine tapping setups where chip accumulation is a concern.

Key Features

• Thread forming design displaces material rather than cutting, eliminating chips in blind holes
• Cobalt high-speed steel construction provides elevated heat and abrasion resistance
• Steam oxide coating reduces friction and supports lubricant retention during operation
• Modified bottoming chamfer (2 to 2.5 chamfered threads) enables threading close to blind hole bottoms
• Class 3B fit with H2 thread limit for tight-tolerance threaded connections
• Right-hand thread direction, compatible with standard tapping equipment and tap wrenches

Compatibility

Designed for blind hole thread forming in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Compatible with standard 3-48 UNC tapping applications requiring a Class 3B fit and H2 thread limit.

Installation Notes

Thread forming taps require a specific tap drill size that differs from cutting taps — always consult a thread forming drill chart for the correct hole diameter before tapping. Apply a suitable tapping fluid or cutting oil rated for the workpiece material, especially when working with stainless or hardened steel. Secure the workpiece firmly and align the tap perpendicular to the hole to avoid tap breakage. Use a calibrated torque-limiting tap wrench or CNC tapping cycle to prevent overloading the tap in harder materials.