Thread Tap FANAR UNC 5/16-18 DIN 371C R40 (2B) HSSE 800

FANAR thread tap UNC 5/16-18 DIN 371C R40 (2B) HSSE 800 is a hand or machine tap designed for cutting internal Unified National Coarse (UNC) threads. Manufactured to DIN 371C form with a radius R40 and tolerance class 2B, the tap is made from HSSE 800 high-speed steel with cobalt for improved wear resistance. It is suitable for producing accurate internal threads in a range of suitable materials and can be used in both through and blind hole applications depending on the machining setup.

Advantages

The combination of DIN 371C form and radius R40 provides stable thread geometry and reduced stress at the thread root. Tolerance 2B ensures standard internal thread fit for common assembly use. HSSE 800 material offers enhanced hardness and heat resistance compared with conventional high-speed steels, extending tool life in tougher cutting conditions. The tap’s design allows use by hand or in machine spindles, supporting flexible application in workshop and production environments.

Suitable for

• Cutting internal UNC 5/16-18 threads in metals and compatible alloys
• Maintenance and repair operations requiring standard 2B internal threads
• Assembly and fabrication tasks in mechanical and structural components
• Through-hole and blind-hole tapping where DIN 371C form and R40 radius are required

Key specifications

• Thread standard: Unified National Coarse (UNC) 5/16-18
• Form: DIN 371C with radius R40
• Tolerance class: 2B (internal)
• Material grade: HSSE 800 (high-speed steel with cobalt)
• Operation: suitable for hand tapping and machine tapping

How to use

Select the correct drill size for the UNC 5/16-18 tap and secure the workpiece. For hand tapping, use a suitable tap wrench and align the tap perpendicular to the workpiece surface. Apply cutting fluid appropriate to the work material to reduce friction and heat. Start cutting with light pressure until threads are engaged, then proceed steadily, reversing periodically to break chips if necessary. For machine tapping, ensure proper spindle alignment, correct speed and feed settings for the material, and use rigid fixturing to prevent deflection. Clean chips from the flutes frequently and inspect the produced thread for fit and finish.

Usage recommendations

Use appropriate cutting fluid and recommended drill pilot size for UNC 5/16-18 to maximize tool life. Avoid excessive spindle speed and radial loads when machine tapping; ensure correct clamping and alignment. Replace the tap if wear or chipping is detected to maintain thread quality and assembly reliability.