High-strength bolts are generally used to connect highway bridges, railroad tracks, ultra-high pressure and high-pressure machinery and equipment. The quality of high-strength bolts needs to be strictly supervised. So what aspects need to be paid attention to during project acceptance? First of all, everyone should check the packaging to see if the packaging box is extremely waterproof. The shell should be a matching package of high-strength bolt connections. Different types of high-strength bolts cannot be mixed together according to regulations. The quality of each shell should not exceed 40KG. It is up to the manufacturer to choose how to separate the packaging inside the wooden box. On the outside of the wooden box, there should be the name of the manufacturer, the name of the product, the standard number and the batch number, specification and size of the product, and if it is more stringent, obvious signs such as weight should be added. When inspecting, be sure to check the product quality inspection report and shipment certificate provided by the manufacturer in accordance with the batch. When leaving the factory, the inspection shall be carried out according to the batch. The same performance level and raw material shall be the same batch number as the furnace number and thread standard length. Anchor bolts manufactured by machining, heat treatment and surface treatment are of the same batch number. One thing to consider here is that the large batch of high-strength bolted joints that guarantee the supply of torque coefficients should be 3,000 sets. After the production of high-strength bolts, the manufacturer needs to do hot-dip galvanizing. What is the reason? What is the difference between high-strength bolts before and after hot-dip galvanizing? 1. After hot-dip galvanizing, the coating on the surface of the anchor bolts may form a special zinc layer structure. During transportation and use, this type of structure can protect the anchor bolts from mechanical damage and affect their application. 2. The whole process of hot-dip galvanizing is simpler and more convenient than similar coatings. 3. Hot-dip galvanized products are more durable in environments such as saline soil, damp and cold, and near the sea. Tests have shown that standard hot-dip galvanized products can maintain normal operation for more than 30 years without replacement or repair. 4. After hot-dip galvanizing, the position of vulnerable parts can be properly maintained; such as recesses, bevels, milling places, etc. 5. The production and processing costs of hot-dip galvanizing (hot-dip galvanizing) similar to anti-corrosion coatings are more favorable.