Hex screws DIN 931/933 (ISO 4014/4017) Hex screws electro-zinc plated 8.8 are high-quality screws that are ideal for ensuring strong and reliable joints in various construction and machine applications. Manufactured in accordance with the DIN 931/933 standard and meeting strict quality requirements. The screws have an electro-zinc plated surface treatment according to ISO 4042, which gives them corrosion protection for indoor and protected installations. The hex head gives better grip and torque transfer during installation. Strength class 8.8 gives a minimum tensile strength of 800 MPa and a yield strength of 640 MPa. DIN 931 (ISO 4014) is supplied partially threaded with an unthreaded shank section that carries shear load in thick structures. DIN 933 (ISO 4017) is fully threaded and gives full flexibility in grip length, preferred in machine assembly and threaded holes. The choice is determined by the geometry of the connection and the type of load. For seawater-exposed and corrosive environments, A4 acid-resistant according to ISO 3506 is the correct alternative. Specification Standard: DIN 931 / ISO 4014 (partially threaded) and DIN 933 / ISO 4017 (fully threaded) Strength class: 8.8, min. tensile strength 800 MPa, yield strength 640 MPa Surface treatment: Electro-zinc plated according to ISO 4042 Corrosion protection: Indoor and protected industrial environments Indicative torque M12: 83 Nm at coefficient of friction 0.14, dry and uncoated Indicative torque M16: 206 Nm at coefficient of friction 0.14, dry and uncoated Dimension range: M6 to M24 in stock Key properties DIN 931/933 and ISO 4014/4017 are equivalent standards with identical dimensional requirements, full compatibility across European and international specification. DIN 931 partially threaded is the right choice where the shank section carries shear load in thick structures and loaded flange connections. DIN 933 fully threaded gives full thread flexibility and is preferred in machine assembly and threaded holes. Torque values must be adjusted when using lubricant or an alternative coating. Contact Industrisalg for the correct calculation.