How do you make screws, bolts and similar? Today, we talk about the thread rolling process.

What are you doing during the thread rolling process?

The thread rolling process allows the cold forming. The threats are formed on cylindrical sections and making them go through 2 molds that translate and rotate. How do you get the profile? During this process, the profile is obtained through a process of plastic deformation of material with which they can perform mass external threads. In practice, what is a rolling process? It’s a process of coining cold on special machines (also called rolling machines). These are highly productive automatic cycle machines.

What molds you use?

You use 2 types of molds (also called combs):

• Flat ones (e.g. incoming flat moulds )

• Roll ones. (e.g. moulds with 2 rolls)

What are the difference about combs?

THREAD ROLLING MACHINE WITH FLAT COMBS

Threads are formed on a bar or a wire with:

• mean inclination of the propeller

• thread shape

that correspond to:

• the inclination

• to the profile of the scuffing combs

How are the combs?

• Fixed comb: it is mounted with a slight inclination in order to cause the penetration of the piece

• Second comb: it is equipped with alternate cutting movement with allocation that allows you to move the scuffing by half-step.

How do you make threading?

In this case takes place in a single pass. The rough that is introduced at one end of the fixed bearing, it is dragged and worked up at the other end. Thanks to the action of the pressure of the combs (progressive) you create the compartments of the thread without:

• cutting actions

• chip formation