The pretreatment process is a key process that determines the quality of nickel-phosphorus plating on high-strength bolts. The purpose of this process is to remove the passivation layer on the surface of the bolt and prevent the regeneration of the passivation film. The execution of this process directly determines the degree of bonding between the substrate and the coating. Most of the quality accidents in production are caused by poor pretreatment of bolts. Before plating, the oil, rust and oxide scale attached to the surface of the bolt must be carefully removed; the difference with electroplating is that it should be inspected more carefully, and plating is absolutely not allowed on unclean bolts. ① Inspection of bolts: Visual inspection of the surface quality of bolts requires that any burrs left by processing must be removed, and sharp edges and corners must be rounded. ② Manual degreasing; ensure that the surface of the substrate is free of oil stains. ③ Soak and remove oil; boil the bolts in alkaline water to remove the surface oil. ④ Pickling: In order to prevent the alkaline degreasing solution from contaminating the flash nickel plating tank, electro-activation treatment is carried out with pickling solution before flash nickel plating. ⑤ Electro-activation; electro-activation treatment with acid solution. ⑥ Flash nickel plating; flash nickel plating should be used for low alloy steel to increase the bonding strength between the coating and the substrate.
rivet automatic feeding device comprises a feeding installation frame, the upper end of the feeding installation frame is provided with a horizontally arranged receiving block mounting plate, the upper surface of the receiving block installation plate is provided with a rivet receiving block, a rivet The upper surface of the receiving block is provided with a receiving block movable groove that opens upward and completely penetrates left and right. The left movable receiving rod can be embedded in the receiving block movable groove relatively movably, and the right movable receiving rod is located on the right end side of the left movable receiving rod. The receiving rod, the right end of the left movable receiving rod is provided with a left receiving groove that opens upward, and the left end of the right movable receiving block is provided with a right receiving groove that opens upward;
The head of the traditional screw is located outside the threaded hole and occupies a large space, which is not suitable for occasions with small space, nor is it suitable for occasions where the outer surface of the component is a working surface. For example, in the field of electronic products, or when connecting the shaft and the shaft sleeve, the machine screw with a fully threaded structure on the outer surface is widely used.
Hexagon nuts are also called hexagon nuts. Generally, there are many types of nuts, such as hexagon nuts, round nuts, square nuts and so on. Some standards for nuts are still relatively clear. Some specifications and size standards, material requirements standards, electroplating standards, etc. are relatively clear. Different types of nuts also have different standards. Let's introduce the specifications and standards of the nuts in detail.
Self-tapping screw is a kind of threaded fastener that self-tapping and drilling the matching female thread in the pre-drilled hole of metal or non-metal material. When using self-tapping screw, a flat washer is often required to protect the fastening surface. Traditional When the self-tapping screw is used, the flat pad is easy to fall off, resulting in low work efficiency. In view of this, we propose a combined structure of the stuck self-tapping screw spring washer that prevents the flat pad from falling off.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: machine screws, hexagon socket head bolts, D6 hollow pins, plastic screws and other products, we can provide you with suitable fastener solutions for you Program.