Tap FANAR GWINTOWNIK UNC 1/4-20 DIN 371C R40 (2B) HSSE TN 800X

FANAR GWINTOWNIK UNC 1/4-20 DIN 371C R40 (2B) HSSE TN 800X is a high-speed steel (HSSE) machine tap engineered for cutting internal UNC 1/4-20 threads to DIN 371C dimensions. The tap features R40 geometry and a 2B tolerance class, designed to produce consistent, accurate threads in through and blind holes. It is suitable for production and repair environments where repeatability and tool life are important.

Advantages

The HSSE material provides improved wear resistance and toughness compared with standard high-speed steels, helping to extend tool life in serial production. The R40 geometry optimizes chip formation and evacuation, reducing the risk of chip jamming in both through and blind hole operations. The 2B tolerance class ensures compatibility with standard UNC internal thread fits and reliable assembly with mating fasteners.

Suitable for

• Tapping UNC 1/4-20 internal threads in steel and similar materials
• Through hole and blind hole tapping
• Production runs and repair or maintenance tasks requiring repeatable thread quality
• Use in drilling/tapping machines and CNC machining centres

Key specifications

• Thread form: UNC 1/4-20
• Standard: DIN 371C
• Geometry: R40
• Tolerance class: 2B (internal threads)
• Material: HSSE (high-speed steel with enhanced properties)
• Application: through hole and blind hole tapping in steel and similar materials

How to use

Select appropriate spindle speed and feed for the workpiece material and the tap size, and secure the workpiece to prevent movement. Use cutting fluid suitable for steel to improve lubrication and cooling during tapping. For blind holes, use peck tapping or withdraw slightly to clear chips if required. Align the tap accurately with the hole axis and engage steadily to avoid cross-threading; reverse the tap to break chips and clear the flute before completing the thread.

Usage recommendations

For best results, match speed and feed to the workpiece material and toolholder rigidity, maintain adequate cutting fluid flow, and inspect threads periodically for wear. Replace the tap when thread quality or dimensional accuracy degrades to avoid damaged assemblies.