Selection Guide of Stainless Steel Screws

Q1: What are the common materials of stainless steel screws?

A1: Common materials include 304, 316, 201 stainless steel. 304 stainless steel screws have good corrosion resistance and are suitable for general environments; 316 stainless steel screws have better corrosion resistance, suitable for harsh environments such as marine and chemical industries; 201 stainless steel screws are low-cost but poor in corrosion resistance, suitable for dry indoor environments.

Q2: What factors should be considered when selecting stainless steel screws?

A2: 1. Use environment-consider humidity, corrosiveness (such as whether there are chloride ions), and temperature; 2. Load requirements-select the appropriate specification and strength grade according to the bearing capacity; 3. Connection material-ensure compatibility with the connected material to avoid galvanic corrosion; 4. Installation method-choose the appropriate head type and thread type.

Q3: What is the difference between 304 and 316 stainless steel screws?

A3: The main difference is the corrosion resistance and cost. 316 stainless steel screws contain molybdenum, which has better resistance to chloride ion corrosion than 304; in terms of mechanical properties, the tensile strength and yield strength of 316 are slightly higher than 304; the cost of 316 stainless steel screws is about 30-50% higher than 304.

Q4: Can stainless steel screws be used with carbon steel components?

A4: It is not recommended. When stainless steel screws are in contact with carbon steel components in a humid environment, galvanic corrosion will occur. Carbon steel is more active and will corrode as the anode, while stainless steel will be protected as the cathode. If it is necessary to use them together, an insulating gasket should be placed between them to isolate the two metals.

Q5: How to prevent stainless steel screws from seizing (locking)?

A5: 1. Choose the appropriate thread lubricant (such as anti-seize paste) during installation; 2. Control the installation torque, avoid over-tightening; 3. Avoid installing in a high-temperature environment, as high temperature will increase the risk of seizing; 4. Use screws with coated surfaces (such as PTFE coating), which can reduce friction.