The manufacturing process of bolts using a combination of a double stroke heading machine, trimming machine, and roll threading machine involves several steps. Here’s a general overview of how bolts are produced using these machines:

1. Heading: The wire is fed into the double stroke heading machine, which has two moving punches. In the first stroke, the first punch partially forms the head of the bolt, while the second punch shapes the shank. In the second stroke, the second punch completes the formation of the bolt head.

2. Trimming: After heading, the bolt is transferred to the trimming machine. The trimming machine removes excess material from the bolt’s head, ensuring a clean, uniform shape. It uses cutting tools or dies to precisely trim the bolt head to the required dimensions and remove any rough edges or burrs.

3. Thread Rolling: Once the trimming process is complete, the bolt is ready for thread rolling. The bolt is fed into the roll threading machine, which has sets of dies with thread profiles. The bolt is rotated while the dies press against the shank, displacing the material and forming precise threads on the bolt. Roll threading provides strong and uniform threads with excellent dimensional accuracy.

4. Polishing Drum: Its main purpose is to improve the appearance and surface quality of the bolts by removing any burrs, sharp edges, or surface imperfections that may have been left after the earlier manufacturing steps.

5. Dryer: A dryer is used to remove oil or any residual liquids from the bolts after they have undergone various processes.

6. Lathe Machine: Conventional lathe machines are utilized for turning operations, which involve shaping cylindrical parts of the tools and dies.

7. Grinding Machine: Surface grinders, cylindrical grinders, or tool and cutter grinders are used to achieve the required surface finish, shape, and sharpness of the tools and dies.