Osg 1410104301 Thread Forming Tap M8x1.25 Cobalt

Product Description

The OSG 1410104301 is a thread forming tap in the HY-PRO NRT series, designed to produce M8x1.25 metric coarse internal threads without cutting chips. Made from cobalt high-speed steel and finished with a steam oxide coating, this bottoming-style tap is built for use in blind hole applications where full thread depth close to the bottom of the bore is required. The cobalt substrate improves hardness and heat resistance compared to standard HSS, making it suitable for demanding materials. With 1 to 1.5 chamfered threads and a Class 6H fit at Thread Limit D9, it delivers accurate, consistent threads in production and maintenance environments. Licensed machinists and toolroom technicians are the primary users.

This tap is rated for blind hole threading in a broad range of metallic materials including alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The thread forming process cold-forms the thread profile rather than cutting, eliminating chips and reducing the risk of chip packing in blind holes. It is well-suited for both CNC tapping centers and manual tap handles in job shop, production machining, and MRO settings where M8x1.25 threads are common in fastener bosses, fluid port fittings, and structural assemblies.

Key Features

• Cobalt HSS construction for improved hardness and thermal resistance in tough materials
• Steam oxide coating reduces friction and improves lubricity during the forming process
• Bottoming chamfer with 1 to 1.5 chamfered threads for threading close to the bottom of blind holes
• Thread forming design eliminates chips, reducing tap breakage risk in blind hole work
• Class 6H fit at Thread Limit D9 for accurate, standardized metric thread production
• Compatible with alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum

Compatibility

Designed for blind hole threading in alloy steel, aluminum, carbon steel, die steel, hardened steel, and stainless steel workpieces requiring M8x1.25 metric coarse internal threads. Material application codes P and N apply.

Installation Notes

Thread forming taps require a specific forming drill size larger than a standard cut-tap drill to achieve the correct material displacement and final thread class — consult OSG or a machining reference for the correct pre-drill diameter for M8x1.25 6H forming taps. Power down or disengage the spindle and apply cutting fluid or tapping compound rated for the workpiece material before beginning the tapping cycle. Ensure the tap is aligned perpendicular to the workpiece surface to avoid thread distortion or tap breakage. Do not use this tap for through-hole applications where chip-clearing geometry is needed.