ASTM A325 / a325m large hexagon bolt, heavy hexagon head bolt
Square head bolts are divided into 4.8 class bolts, 8.8 class bolts, 10.9 class bolts and 12.9 class bolts according to the grade of high strength.It is widely used in the electrical and electronic industry, water conservancy engineering industry, electrical products, mechanical equipment, chemical equipment, ships, vehicles, steel structures and so on.
It is distinguished from other bolts by its shallow mushroom head and that the shank cross-section of the bolt is circular for most of its length, but the portion immediately beneath the head is formed into a square section.Carriage bolts are designed to sink into the wood as you tighten the nut, essentially creating their own pockets. Except you're building with very hard wood, this should work fine.Carriage bolt is designed to sink into the wood as you tighten with nut, essentially creating their own pockets. Unless you're building with very hard wood, this should work fine. You can tap the bolts inward with a hammer as you tighten the nuts to assist.Carriage bolts are designed so that on one side of an assembly that there are no protruding bits for things to catch on. The round head part will provide that as opposed to there being a hex or square head sticking out. In your case with a chair kit the general idea is that the heads of the carriage bolts should face toward the side of the chair where the user will be. As such the threaded bolt ends will want to be down underneath or toward a generally non use for surface of the chair.
||Grade 10.9 , 12.9 Stainless Steel M2 - M100 Square Head Bolt Full Thread
||M2 - M100
||DIN, ANSI, GB, ISO, BS
||Grade 10.9 , 12.9
||Full Thread Or Half Thread
||Medium hardening rate, suitable for general cold processing and stretching, cold processing performance is good, commonly used for external hexagonal bolts, nuts and gaskets products.
Adding molybdenum, corrosion resistance is better than 304, especially suitable for seawater and chemical media, more corrosion resistance and pitting resistance.
Friction type high strength bolt: suitable for steel frame structure beam, column connection, solid web beam connection, heavy crane beam connection of industrial workshop, brake system and important structure under dynamic load.
High strength Bolts: shear connections in structures that allow for a small amount of sliding or are subjected to indirect dynamic loads.
Tensile high strength bolts: when the bolts are pulled, the fatigue strength is low. Under dynamic load, its bearing capacity is not more than 0.6P (P is the allowable axial force of bolts). Therefore, it is only suitable for static loading, such as flange butt joint, T type joint and so on.