boltes metric
A fully threaded screw metric has threads running from under the head to the tip. These screws are manufactured per standards ISO 4014 DIN 931 and ISO 4017 DIN 933. Common diameters range from M1.6 to M64 with standard or fine pitch. Key strength classes are 4.8, 8.8, 10.9, and 12.9. Their lengths typically vary from 6 mm to 500 mm. Head types include hex, socket, button, and slotted. Materials are carbon steel, stainless steel A2/A4, or copper-beryllium alloys. Fully threaded screws are used for general connections requiring free-spinning nuts.
A stud bolt double-ended is a threaded rod with threads on both ends and an unthreaded shank in the middle. They are produced per ISO 4014 tap end stud and ASTM A193 for high-temperature applications. Threads can be concentric or with different pitches. Overall length typically ranges from 25 mm to 300 mm. Common nominal diameters are between M8 and M36. The strength class is often 8.8 or higher. These are primarily used in flange connections, hydraulic systems, and machine panels. Their installation requires two nuts.
