Thread grinding machines are grinders that can do threading process on the work pieces through the grinding mechanism by wheels. There are mainly two ways of thread grinding, one is thread grinding and the other is thread rolling and both are done by wheels. Although thread grinding is less cost effective compared to thread rolling, yet manufacturers prefer thread grinding a lot. Because for many applications that need high degrees of accuracy or precision repeatability, ground ball screws are worth the additional costs in order to ensure the screw assembly is functioning. That is why in the metal working and screw making sectors, thread grinding by wheel is the primary type of threading during which a CNC machinery with an abrasive grinding wheel is utilized to cut the threads of the targeted screws by the thread grinding machines. Wheel quality also matters to this process.
Screws created through CNC thread grinding process have to be able to meet custom backlash requirements as well as specifications, and tight tolerances requested by the users. With all that requirements are done, so the outputs are meaningful and the wheel tools are necessary for the wheeling. There are several types of grinding machines, such as external grinder, internal grinder, roll grinder, surface grinder, and many other custom types, and all the grinding requires wheels.
In regard to the screw making grinding machines, it is about external and threading, while the processing is rather complicated. Either external or internal, the wheel shall be able to wheel it. Thereafter, professional manufacturers may tend to use thread grinding over thread rolling if they are using a high-hardness screw material. Because some materials are too hard to allow for thread rolling processes and the grinding wheels cannot cope with it. Furthermore, thread grinding process also allows for threads to be cut after the material has been heat treated. Even more, for threads to be cut on a complex design part, this type of grinders are very useful and practical due to the great flexibility.
Thread rolling is not like CNC thread grinding. This is a metal rolling process adopted extensively in the production by manufacturing industry to produce screw units, bolts and other fasteners, etc. A common thread rolling process used in industry to manufacture threaded parts involves forming the threads into the metal of a blank by a pressing and rolling action between two dies. As a result, that dies’ surfaces contain the shape and the force of the movement. This forms the threads into the materials. A similar metal forming process has been developed for the production of gears. Thread rolling now is designed with an extremely high productivity rate, significantly higher than producing threaded parts by ordinary machining processes.
If the threading is not the option, machining is the alternative method to industrial manufacturing of the threaded parts. Producing threads by this method has several other benefits compared with machining process. Forming will harden the metal through cold working. This process does not waste material by cutting, and produces a favorable grain structure to strengthen the part with respect to its function. All these profile grinding processes are grinding family members. In the article we will introduce the grinding process by wheels as a common knowledge for readers to get a rough picture of this particular kind of cutting process for the finishing step of metal working work pieces.
The definition of cylindrical grinding is that the machine must have four critical actions: Firstly the work piece must be constantly rotating; secondly, the grinding wheel must be rotating constantly; thirdly, the grinding wheel is fed forwards and backwards towards the work piece. Last, work pieces are traversed with respect to the grinding wheel. The majority of cylindrical grinders today utilize all the four movements, while there are still grinders that only utilize three of the four actions to process because that may be enough.
However, the grinding wheels are so critical in that with no wheels the grinding cannot be done. To compare with other similar models, even though roll grinding is nearly the same as cylindrical grinding in most of the processing details, there are some critical differences between the two grinders. Roll grinding method is developed specifically for certain issues that usually require machines that are designed for heavy duty works with resistant wheels.
There is a huge number of grinding machine inventory. There are belt grinder, bench grinder, cylindrical grinder, surface grinder, tool & cutter grinder, jig grinder, gear grinder, die grinder, angle grinder, and roll grinder, and other custom models of grinding process with wheels. When the two are put together into comparison, it is found that even though surface grinding is similar as cylindrical grinding in most of the processing details, there are some critical differences between the two categories.
Surface grinding method is developed specifically for certain issues that usually require machines that are designed for such machining works. Therefore, these machines are larger in size, heavier in weight, and are more rigid if compared with plain cylindrical grinders. So, normally these machines have no provision for doing tapering jobs.
IMTS Exhibition includes manufacturers from around the world. Send us a message with your requirements and our IMTS Experts will happily help you with your questions.