ISO 6157-1 Fasteners - Surface Discontinuities - General Requirements

EUROLAB, with its state-of-the-art accredited laboratories and expert team, offers precise and rapid testing services within the scope of ISO 6157-1 testing. This part of ISO 6157 specifies limits for various types of surface discontinuities on bolts, screws and studs for general requirements.

Applies to bolts, screws and studs with the following properties:

• Nominal thread diameters 5 mm and larger;
• Product qualities A and B;
• Property classes up to and including 10.9, unless otherwise specified in the product standards or agreed between the supplier and the buyer.

The limits of surface discontinuities on bolts, screws and studs for special requirements (e.g. automatic assembly) are specified in ISO 6157-3. When the engineering requirements of the application require closer control of surface discontinuities on bolts, screws and studs, this should be specified in the relevant product standard or the purchaser should specify applicable limits in the inquiry and purchase order.

A crack is a clean (crystalline) fracture that passes through or across grain boundaries and may be trailed by traces of foreign elements. Cracks normally result from excessive stressing of the metal during forging or other forming operations or heat treatment. Where parts have undergone significant reheating, the color of the cracks often varies with scale.

EUROLAB assists manufacturers with ISO 6157-1 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.