washer: ① Flat washer: It is used to overcome the uneven support surface of the workpiece and increase the stress area of the support surface. See GB848, GB95-97 and GB5287. ② Spring (elastic) washer: For spring washer, ...
Determine standards and varieties 1. Selection principles of varieties: (1) Considering the working efficiency of processing and assembly, the number of standard parts should be minimized within the same machine or proje...
Determine category Standard fasteners are divided into ten categories, and the selection should be determined according to the use occasion of the standard fastener and its use function. 1. Bolts: Bolts are generally mat...
Visual inspection 1) Is the supplier identification and performance level identification required? a Bolts and screws with performance level ≥ 4.8 must be marked; b Nuts with performance level ≥5 must be marked; c Bolts,...
1. Small size bolts below 8.8 (M16 and below) Raw material selection: low carbon steel (Q235, 08, 10, 18, etc.) Blank forming method: cold heading Thread forming: rolling or thread rolling (selection method of rolling or...
Although zinc-chromium coating has many advantages, it also has some shortcomings, mainly reflected in: 1). The zinc-chromium coating contains chromium ions that are harmful to the environment and the human body, especia...
