Threaded Studs Both ends are threaded
Full-threaded studs can also be blurred to the studs, where knowledge is different in some places, such as full-threaded studs and stud studs. 2, the whole thread stud structure is uniform, there is no stress concentration point. The studs are subject to stress concentration at the transition between the thread and the light rod, and the high load may fail. But generally there is no head, only two ends are outside the thread of a class of fasteners. When connected, it must be screwed into the part with internal screw holes, the other end through the through hole with the parts, and then screw the nut, even if the two parts fastened into a whole. This type of connection is called a stud connection and is a detachable connection. Mainly used for connecting parts of a larger thickness, requiring a compact structure, or because of frequent demolition, should not be used bolted connection occasions. Commonly used bolts
The national standard specifies hexagon head bolts with screw sizes M3 to M64, A and B. Class A bolts for D <= 24 and L <= 10D or L <= 150mm (by smaller values) Screws for hexagon bolts with D> 24 or L> 10D or L> 150 (by smaller value) Dimensions of bolts for steel connections 3.6,4.6,4.8,5.6,6.8,8.8,9.8 , 10.9, 12.9 and so on more than 10 grades, of which 8.8 and above bolt material for low-carbon alloy steel or medium carbon steel and heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest known as ordinary bolts. The bolt performance grade label consists of two parts, representing the nominal tensile strength and yield ratio of the bolt material, respectively. For example, the performance level of 4.6 bolts, its meaning is: 1, the bolt material nominal tensile strength of 400MPa level; 2, the bolt material yield ratio of 0.6; 3, the bolt material nominal yield strength of 400 × 0.6 = 240MPa Grade performance grade 10.9 high strength bolts, the material after heat treatment, can achieve: 1, the bolt material nominal tensile strength of 1000MPa level; 2, the bolt material yield ratio of 0.9; 3, the bolt material nominal yield strength 1000 × 0.9 = 900MPa grade The meaning of the grade of the bolt is the international standard, the same performance level of the bolt, regardless of its material and origin of the difference, its performance is the same, the design can only use the performance level.