METALMATE® High Tensile Bolts can withstand high levels of strain without losing their strength or structure. These quality-assured threaded fasteners are suitable for use in engineering, production, construction, repair and maintenance. Zinc plated for a longer-lasting finish. 3.1 Certification available. Standard: DIN 931. Quality assurance is extremely important to the METALMATE® brand. The entire purchasing and logistics process complies with international standards. All METALMATE® products are sourced from accredited manufacturers to ensure that only the highest quality threaded fasteners are supplied. Our supply chain partners are subject to regular audits to ensure compliance, overall service quality and timely order fulfilment. We also insist on routine assessments so the ownership of the factory does not threaten the integrity of METALMATE®. These strict quality procedures help us to be more efficient, improve product standards and deliver excellent customer service.