Cylindrical head hex socket screws, also known as hex socket bolts, cup head screws, and hex socket screws, have different names but represent the same meaning. For the commonly used hex socket cylindrical head screws, there are grades 4.8, 8.8, 10.9 and 12.9. It is also called an Allen screw or an Allen bolt. Its head is an inner hexagonal head and also a cylindrical head.

They are classified by material into stainless steel and iron. The stainless steel ones include:

• Stainless steel SUS202 hex socket cylindrical head screws (common stainless steel)
• Stainless steel SUS304 hex socket cylindrical head screws
• Stainless steel SUS316 hex socket cylindrical head screws

According to the strength grades:

• 4.8 grade hex socket cylindrical head screws
• 8.8 grade hex socket cylindrical head screws
• 10.9 grade hex socket cylindrical head screws
• 12.9 grade hex socket cylindrical head screws

Hex socket cylindrical head screws of grade 8.8-12.9 are called high-strength and high-grade hex socket bolts.

The application range of bolts is extensive, including:

• Electronic products
• Mechanical products
• Digital products
• Power equipment
• Mechanical and electrical machinery products

Bolts are also used in ships, vehicles, hydraulic projects, and chemical experiments. They are used in many applications from miniature bolts for precision equipment to large bolts for construction projects.

Ordinary bolt heads are very thick and difficult to deform. If vibration occurs, they may need re-tightening. Flange bolts with thinner parts can slightly deform, allowing for more secure locking.

Flange bolts offer additional advantages:

• Can be used with special tools in confined spaces
• Flange plate provides additional fastening support
• Safer for use with softer, non-wear-resistant materials as they prevent perforation