Gros boulons

What is big bolts?

Big bolts also known as large bolts or giant bolts. Big bolts refer to bolts with a diameter over 20mm and a length of over 100mm, usually used for connecting big structural components. They look like regular bolts but are bigger, stronger, and can carry heavier loads. Large bolts are classified into different grades based on connection needs, such as standard, high-strength, and ultra-high-strength types.We also manufacture giant nuts, please click it.

How to produce huge bolts?

Large bolts are primarily used to connect and secure larger components, such as bridges, stadiums, and wind power plants. Therefore, hot-rolled steel is typically used as the raw material. Below is the entire manufacturing process:

1.Preparing Round Bars: Round bars are used only for producing large bolts. For smaller bolts, coil wire is generally used. Five to six round bars are placed on a saw bed and cut to a uniform length.

2.Heating: An electric furnace heats a section of the raw material, reaching temperatures close to the melting point of steel in just a few seconds.

3.Stamping: The softened end moves to the next step for reshaping, where 60 tons of stamping forms the bolt head into a hexagonal shape. The seamless formation ensures that no joints are left, making the processed bolt more durable. The hot-formed blanks fall into a collection box to cool slowly.

4.Shot Peening: The bolts are rolled together with small steel balls in a shot peening machine. The friction generated removes surface oxides, enhancing the surface’s stress and strength.

5.Molding: Workers place the bolts into a mold and strike the head to create a small central hole at one end for easier installation on a lathe. A machine then shapes the curvature of the bolt’s surface, restoring its original metallic luster. This step requires high precision, as any slight error can affect the thread accuracy, making it difficult for the bolt to screw into the nut.

6.Thread Rolling: Many people think threads are cut, but this step, called thread rolling, uses two plates with thread-rolling grooves. By applying tens of tons of pressure without cutting any metal, threads are formed.

7.Quality Inspection: Finally, quality control personnel inspect the completed bolts. If the threads fit into the gauge, these bolts are ready to fulfill their purpose.

What is the biggest bolt can you produce?

The large bolts we manufacture are generally under M42 in diameter, with a length of about 500 mm. However, we are capable of producing bolts ranging from M30 to M130, with lengths of up to 1500 mm.