Threading is an artistry – one that humans have mastered to produce more screws than any other type of machine element. In its fabrication, we use various techniques to construct threads out of the raw material – from cutting, grinding, and chasing – all the way to rolling and forming.
Threading involves using a lathe or threading machine to cut a helical groove of predetermined pitch into the workpiece. As the piece is turned, the cutter with the necessary form moves axially while trimming off material and ultimately creating the thread. The groove’s depth must equal the desired thread pitch.
There are three primary categorizations of threading:
To form threads on the exterior of a workpiece, the cutter is pushed forward along the circumference of the workpiece in a process known as external threading.
The device that cuts is inserted into the inner diameter of the material, resulting in threads that are carved into the interior of the piece.
To form interior threads, one needs a tap; a handy instrument to craft grooves many and deep.
To fabricate external threads, a die is a nifty device that often comes in handy.
Cutting threads through a single-point tool is the classic approach. As the workpiece rotates, the cutter moves forward and carves a spiral groove whose immersion equals the thread pitch.
To craft threads with durable integrity, thread grinding is a preferred technique. This requires a grinding wheel which is driven into the workpiece to form the threads, a process that is usually used for threads with greater diameter and coarser pitch.
Threads with a delicate pitch can be best cut using chasing – a type of threading similar to single-point cutting. Rather than being fed radially into the workpiece, the cutter is forced in an axial direction in order to efficiently form these small-diameter threads.
To create a threaded exterior on the workpiece, thread rolling is an effective and widely-employed method. Using two specialized dies, the threading is formed by smoothly and consistently pressing onto the chosen piece.
Threading can be done with the use of a forming process, which sees the workpiece being led between two dies to get the thread onto it.
Explore Vast Varieties of Threading
The thread of the workpiece is in perfect alignment with its axis, with no deviation.
A gradual decrease in diameter accompanies the thread, sloping from a thicker to a slender width.
A Pipe, designed with a sloped thread and containing a hole in its center, enables two tubes to be connected as one.
The buttress thread is designed with a tapered shape and crowned with a ridged surface so that it can create a seamless bond between two items of timber.
Acme: With a gradual decrease in thickness and a ridge on each end, this thread allows for the successful conjoining of two pieces of metal.
The connecting link between two cooperating gear wheels is shaped like a coil, often referred to as a worm. This shape allows the moving parts to harmoniously operate in tandem.
A variety of materials exist for crafting threads, such as:
Steel – a key constituent, ubiquitous in threading.
Stainless steel–an alloy renowned for its unparalleled resistance to rust and corrosion.
Aluminum, a featherweight metal that is commonplace in the air and space sector, is renowned for its versatility and durability. It has become an alluring option due to its superior strength-to-weight ratio.
Hefty, reliable brass proves itself to be an ideal material for use in plumbing applications.
Exploring copper’s softness, a metal thoughtfully utilized in electrical applications.
Threading is a process of inventing screw threads through a diverse array of procedures like single-point cutting, grinding, and rolling. To craft these meticulous threads, a lathe or threading machine is utilized to make the workpiece rotate while a correctly formed cutter eliminates material to generate the thread.