Osg 1208205 Spiral Point Tap 8-36 Unf Tin Hss

Product Description

The OSG 1208205 is a spiral point tap designed for cutting internal threads in a wide range of metals. It features an 8-36 UNF thread form with a plug chamfer, 2 flutes, and a TiN (titanium nitride) coating over a high-speed steel body. The plug chamfer style makes it well suited for through-hole tapping applications where the tap can advance through the workpiece and push chips forward ahead of the cutting zone. With an H2 thread limit and a 2B class of fit, it produces threads within standard tolerance for most general fastener assemblies. Overall length is 2.125 inches with a thread length of 0.39 inches and a shank diameter of 0.168 inches. Machinists, tool and die technicians, and maintenance mechanics are the primary users.

This tap is rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. It is a right-hand tap, suited for standard right-hand thread cutting on CNC machining centers, drill presses, and manual tapping setups. The 8-36 UNF designation targets fine-pitch thread applications common in instrument assemblies, aerospace components, and precision mechanical hardware where a finer thread engagement is required compared to UNC equivalents. Coolant-through features are not present on this tap, so flood coolant or tapping fluid applied externally is the standard approach.

Key Features

• 8-36 UNF thread form with H2 thread limit and 2B class of fit for standard tolerance assemblies
• Plug chamfer advances chips forward, optimized for through-hole tapping
• TiN coating improves surface hardness and reduces friction against the workpiece
• High-speed steel construction provides toughness across a broad range of workpiece materials
• Right-hand cutting direction, 2-flute design suitable for a variety of setups
• No interrupted thread geometry and no oversize designation — standard production tap profile

Compatibility

Designed for through-hole tapping of 8-36 UNF threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel workpieces. Compatible with standard tapping chucks and holders sized for a 0.168-inch shank diameter.

Installation Notes

Always secure the workpiece fully before tapping and ensure the tap is aligned perpendicular to the drilled hole to avoid thread lead errors or tap breakage. Power down or disengage the spindle drive before manually backing out the tap on manual machines. Apply an appropriate tapping fluid or cutting oil for the specific workpiece material — this is especially important for hardened and high-carbon steels. Follow applicable shop safety practices and machine manufacturer guidelines when setting spindle speed and feed rate for fine-pitch tapping operations.