Hex Head Bolt Making Machine

Shandong Prolu Machinery Technology Co., Ltd. is one of the leading manufacturers and suppliers of hex head bolt making machine in China. With abundant experience, we warmly welcome you to wholesale durable hex head bolt making machine made in China here from our factory. If you have any enquiry about quotation, please feel free to email us.

Hex Head Bolt Making Machine

To produce good quality hex head bolt, not only need good hex head bolt making machines, but also need good materials.

Selecting the right steel is paramount for screw performance, balancing strength, machinability, cost, and corrosion resistance. Here are the most common types:

1. Carbon Steel (Low/Medium Carbon): The undisputed workhorse (e.g., grades like 1008, 1010, 1018, 1022, 1022A). These steels offer excellent cold formability (crucial for heading and thread rolling), good machinability, and high strength after heat treatment (quenching & tempering). They are cost-effective for vast quantities of general-purpose screws. Zinc plating (electroplating or mechanical) is almost always applied for corrosion protection.

2. Boron-Alloyed Steel: A specialized subset of carbon steel. Adding minute amounts of Boron (e.g., 10B21, 10B33) significantly enhances hardenability during heat treatment. This allows screws to achieve higher core strength and better load-bearing capacity (like tensile and yield strength) without requiring expensive alloying elements like Chromium or Molybdenum. Essential for high-strength structural screws.

3. Alloy Steel: Used for high-strength, critical applications (e.g., grades like 4037, 4042, 4140, 4340). These steels incorporate elements like Chromium, Molybdenum, and Nickel, providing superior strength, toughness, and fatigue resistance after heat treatment. Common in automotive, aerospace, and heavy machinery screws demanding exceptional performance under stress.

4. Stainless Steel: Chosen primarily for corrosion resistance. Common grades include:

● Austenitic (e.g., 304, 316): Excellent corrosion resistance, good formability, non-magnetic. 316 offers superior resistance to chlorides. Widely used outdoors, in marine environments, food processing, and medical applications.

● Martensitic (e.g., 410, 420): Can be hardened by heat treatment, offering higher strength than austenitic grades but lower corrosion resistance. Used for cutlery screws, some valves, and applications needing magnetism and moderate corrosion resistance.

● Surface Finishes: Beyond the base steel, finishes like zinc plating (clear, yellow, black), zinc-nickel, hot-dip galvanizing, phosphate coatings, or specialized platings are vital for corrosion protection and appearance.