Threading

Our threading machines are capable of screw threading diametres of 10mm up to 48mm up to 1 metre in length. Our threading service is supported by our in-house brush galvanizing facility which allows us to maintain control of the entire threading process from the starting round section to the fully galvanized end-product.

What is threading?

Threading is the process of adding a screw thread onto the end of bar so that a nut or etc. can be secured to the bar or that the bar can be secured to another object. Threading can be for any length of a bar from just the tip to the entire length of the bar.

Threading has two primary forms, male and female threads. A male thread is an external thread made on the longer object to which a nut or bolt may be added e.g. a bar of circular steel. A female thread is inverse of this i.e. a thread added to the internal section of an object such as the inside of a nut which will be screwed onto a male threaded bar.

Male threads are made by securing the bar in place, and then feeding it through a rotating cutting wheel or die. As the bar passes through, chips are scratched away from the material which provides the consistent depth of the indentation required to form the thread.

Galvanizing screw threads can cause problems if the process is not done correctly.

Threading Process
Threading Process

Threaded items that have been withdrawn from the galvanizing bath will collect excess molten zinc in the grooves of the zinc which may solidify on the bottom side of the thread. To solve this, the threads are brushed to shake off the excess zinc and ensure that the zinc is properly pressed into the grooves of the thread.

Female threads can be made by tapping of thrilling. Tapping, commonly done by hand, is the process of screwing a threaded item
into a non-threaded surface so that a hole is made and the thread of the hole takes the same shape of the item that has been screwed into it e.g. screwed a screw into a plain piece of wood. Thrilling is a combination of threading and drilling, typically done using CNC machinery. A cutting tool tip (shaped like a cone or drill tip) drills the hole and then threaded body of the tool, follows the drill through to add the shape of the thread to the interior of the drilled object.