Osg 1400139300 Thread Forming Tap 7/16-14 Unc Cobalt H6

Product Description

The OSG 1400139300 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, this tap is engineered for demanding threading operations in blind holes. The 7/16-14 UNC thread size with a modified bottoming chamfer (2 to 2.5 chamfered threads) allows threading close to the bottom of a hole. The H6 thread limit ensures tight tolerance control. With an overall length of 3.156 inches and a tapping depth of 1.713 inches, this tap suits production and maintenance threading work performed by machinists, tool and die makers, and maintenance technicians.

This tap is suited for blind hole threading applications across a range of materials including alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel. The thread forming method displaces material rather than cutting it, resulting in stronger threads and no chip evacuation concerns. This makes it well-suited for CNC machining centers, drill presses, and manual tapping operations where hole cleanliness and thread strength are priorities. The modified bottoming chamfer allows use in shallow blind holes where a standard taper or plug tap cannot reach full thread depth.

Key Features

• Thread forming (chipless) design produces stronger threads by cold-working the material
• Cobalt construction provides heat and wear resistance for tough alloy and stainless steel applications
• Modified bottoming chamfer (2 to 2.5 threads) enables threading close to the bottom of blind holes
• H6 thread limit provides consistent, tight tolerance thread production
• Right-hand thread direction, 14 threads per inch, UNC standard
• No coolant-through requirement simplifies setup on standard machine tools

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces. Material application codes P and N confirm suitability for steel and non-ferrous material groups.

Installation Notes

Thread forming taps require a specific forming tap drill size, which is larger than a standard cut tap drill — consult an OSG or standard tap drill chart for the correct pilot hole diameter before use. Apply appropriate tapping fluid or cutting oil rated for the workpiece material to reduce tool wear and improve thread quality. Ensure the workpiece is securely fixtured and the tap is driven on-axis to prevent tap breakage or off-axis threads. Always follow machine shop safety practices and power down or de-energize equipment before changing tooling.