Machine tap DIN 371 C HSS-E for blind holes – Koronet

The DIN 371 C HSS-E machine tap from Koronet is a precision tool designed for making ISO metric internal threads in blind holes. Made of high-quality high-speed cobalt steel HSS-E (HSSE), it ensures stable operation, good wear resistance and high thread quality in workshop and production conditions.

The tool is dedicated to the processing of structural steels, low-alloy steels and medium-strength materials, where control of the threading process and dimensional repeatability are important.

HSS-E steel – durability and stability of the process

The tap is made of high-speed steel with the addition of cobalt (HSS-E), which is characterized by:

• increased resistance to torsional loads,

• better stability of operation at elevated temperatures,

• higher wear resistance compared to classic HSS steel.

Thanks to these properties, the tool provides even cutting, stable guidance and a longer service life while maintaining a high thread quality.

C geometry – for blind holes

The tap has a C-type, designed for:

• threading in blind holes,

• working close to the bottom of the hole,

• precise thread forming with a short inlet cone.

This geometry allows for accurate threading in a confined working space and reduces the risk of damage to the bottom of the hole.

Spiral grooves – effective chip evacuation

The spiral grooves used ensure:

• effective chip discharge to the top of the hole,

• Reduced risk of chip jamming in the cutting zone

• more stable and safer operation in blind holes.

This solution improves the quality of the thread surface and increases the reliability of the machine threading process.

DIN 371 standard – compact design

Compliance with DIN 371 means:

• shorter, compact tool design,

• Suitable for standard thread depths

• stable guidance in machine holders.

The tap is adapted to work on CNC machine tools and conventional machines, where precision and repeatability are key.

Application

The DIN 371 C HSS-E machine tap is recommended for machining:

• structural steels,

• low-alloy and alloy steels,

• medium-strength materials,

• Parts that require threading in blind holes.

The tool ensures stable operation, high thread quality and reliability in everyday production and workshop applications.