Frequently Asked Questions

Older German standards such as DIN 933 and DIN 931 have largely been replaced by ISO 4017 and ISO 4014. Most dimensions are the same; for M10 and M12 the wrench size is 17/19 mm in DIN and 16/18 mm in ISO. State the standard clearly when ordering.

The first number is tensile strength divided by 100 (8 → 800 MPa), the second the yield/tensile ratio (0.8 → 640 MPa yield). 10.9: 1,000 MPa tensile, 900 MPa yield; 12.9: 1,200 MPa tensile, 1,080 MPa yield.

For indoor use, electro-galvanizing (5-12 µm); for outdoor and steel construction, hot-dip galvanizing; for high-strength (10.9 / 12.9) and corrosion-resistant applications, Geomet. Electrolytic coating carries a hydrogen embrittlement risk for 10.9 and above.

Catalog products are sold by carton (usually 100-1,000 pieces). The minimum batch for special manufacturing is 5,000 pieces. Minimum purchase terms for dealers vary by tier.

An EN 10204 3.1 certificate is issued for every lot. Enter the lot number on the product label into the certificate lookup tool on our site to download the PDF report. For 3.2, you must request it with the order.

Samples of standard products are free up to 50 pieces. Special-manufacture samples include tooling cost and are quoted individually.

Fill in the dealer application form and upload your tax plate and trade registry gazette. After credit assessment and the contract, your B2B portal access opens.

Torque depends on bolt diameter, strength class and friction coefficient (K). The torque calculator on our site gives an approximate value; for safety-critical joints VDI 2230 and the torque-angle method should be applied.