Osg 1400138400 Thread Forming Tap 3/8-24 Unf Plug Cobalt

Product Description

The OSG 1400138400 is a thread forming tap in the HY-PRO NRT series, designed for cold-forming internal threads without cutting or producing chips. Built from cobalt high-speed steel with a bright finish, it is rated to a H6 thread limit and configured with a plug chamfer featuring 4 to 4.5 chamfered threads for gradual thread engagement. The tap handles 3/8-24 UNF right-hand threading in through-hole applications. Overall length is 2.9380 inches with a thread length of 0.7520 inches and a tapping depth of 1.2520 inches. Machinists and tool and die professionals use this tap in production and job-shop environments where thread strength and surface finish are critical.

This tap is suited for through-hole threading operations in a wide range of metalworking applications. It is rated for use in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. The cold-forming process work-hardens the thread form, producing stronger threads compared to cut taps. It is commonly run on CNC machining centers, drill presses, and tapping machines where consistent thread quality across production runs is required.

Key Features

• 3/8-24 UNF right-hand thread form for through-hole applications
• Cobalt high-speed steel construction for heat and wear resistance in tough materials
• Bright finish with H6 thread limit for controlled fit and dimensional accuracy
• Plug chamfer with 4 to 4.5 chamfered threads for gradual thread engagement
• Cold-forming design produces no chips, reducing clogging and improving thread strength
• Compatible with alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel

Compatibility

Rated for use in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N apply. Designed for through-hole threading operations in production and job-shop machining environments.

Installation Notes

Installation is performed by machinists using CNC equipment, drill presses, or dedicated tapping machines. Ensure the workpiece is securely fixtured and the spindle is properly aligned before tapping. Use a suitable tapping fluid or cutting oil rated for the workpiece material to extend tap life and maintain thread quality. Do not reverse the tap abruptly in hardened or high-alloy materials, as cobalt taps are resistant to heat but can fracture under lateral stress.