Osg 1625083215 Thread Forming Tap 8-32 Unc Bottoming

Product Description

The OSG 1625083215 is a thread forming tap designed for 8-32 UNC threading in blind hole applications. Part of the OSG EXOPRO XPF Series 16250, this bottoming-style tap uses a cold-forming process — displacing material rather than cutting it — to produce strong, work-hardened threads with no chips. Built from cobalt high speed steel with a V-coating, it carries a 2B class of fit and H5 thread limit. Overall length is 2.48 inches with a tapping depth of 0.853 inches. It is installed by machinists and tool-and-die professionals on CNC and manual tapping equipment.

This tap is suited for blind hole threading across a wide range of materials including aluminum, cast aluminum, carbon steel, alloy steel, die steel, stainless steel, hardened steel, high-nickel alloy, and titanium. The bottoming chamfer — 1.5 to 2 chamfered threads — allows threading close to the bottom of a blind hole, making it appropriate for tight-tolerance components in manufacturing, maintenance, and repair operations. Right-hand thread direction is standard for conventional tapping setups.

Key Features

• Thread forming (chipless) operation produces work-hardened threads and eliminates chip evacuation concerns in blind holes
• Cobalt HSS construction with V-coating for extended tool life in tough materials including stainless steel and titanium
• Bottoming chamfer (1.5-2P) enables threading to near the bottom of blind holes
• H5 thread limit and 2B class of fit for consistent, tolerance-controlled thread production
• Right-hand thread direction, compatible with standard tapping heads and CNC spindles
• No coolant-through required — suitable for conventional flood or mist cooling setups

Compatibility

Designed for use in blind hole tapping fixtures, CNC machining centers, and manual tapping arms where 8-32 UNC 2B thread forming is required. Compatible material applications include aluminum, cast aluminum, carbon steel, alloy steel, die steel, stainless steel, hardened steel, high-nickel alloy, and titanium (material application codes P, M, N, H).

Installation Notes

Thread forming taps require the correct tap drill size for the material and class of fit — use the manufacturer-specified forming tap drill chart rather than a standard cut-tap drill chart, as the hole size requirements differ. Ensure the workpiece is securely fixtured and the tap is properly aligned to the hole axis before engaging. Apply appropriate tapping fluid or cutting oil for the material being tapped. Power down and de-energize any CNC equipment before changing or inspecting tooling.