Bolt DIN 7991 M4x25 10,9 zinc-nickel black

A countersunk head bolt is a fastener consisting of a metric thread and a head with slots for various types of sockets.

Area of application DIN 7991 bolts are used for connecting and fastening parts and structures in construction and mechanical engineering.

The material of manufacture is high-strength structural alloy steel. The high strength class of 10.9 allows the bolts to be used in heavy-duty connections.

Coating: Black zinc-nickel. Zinc-nickel coating is an innovative anti-corrosion solution for fasteners, combining high protective properties, mechanical strength, and environmental safety.

The key advantages of zinc-nickel coating are:

• Excellent corrosion resistance - more than three times higher than that of conventional zinc;
• Low risk of hydrogen embrittlement;
• Compatibility with aluminum - does not form galvanic couples and does not cause corrosion in combination with aluminum parts;
• Increased heat resistance - retains its protective properties during temperature changes and during prolonged operation in high-temperature conditions;
• Mechanical strength - harder than pure zinc, has better resistance to scratches and wear;
• Environmental friendliness - less oxidation products are formed, resulting in lower zinc emissions into the environment throughout the product's life cycle.
• Aesthetics and inconspicuousness - the coating has a deep black color, which makes it inconspicuous.