There are many elements to consider when threading a workpiece. When is a solid carbide thread mill better than an indexable? How does the workpiece material behavior impact thread milling? Understanding the program as well as diagnosing issues that arise are just as important. Luckily, thread milling can be better understood by asking five specific questions.
Please visit our website for more information on this topic.
When to thread mill instead of tap?
There are many instances where a user would want to consider using a thread mill instead of a tap. In numerous cases, this comes back to one common issue: taps break. Because the tap is the exact same size as the hole, there is a lot of pressure when a user forces the threads into the hole'even more so in difficult-to-machine materials. Additionally, a tap's cutting edges are constantly in the cut, thus generating more heat. A thread mill on the other hand has little contact with the material, and the heat generated is much lower'an added benefit in any manufacturing process. Finally, when using a tap, chips are more difficult to form and remove.
All of these things mentioned above lend themselves to tool failure. When the tap breaks off, it often results in a scrapped part, so using a tap works better when it is an inexpensive part being made. If it is a more expensive part and the tap breaks, the user is now faced with the challenge of trying to remove the tap and salvage the part. This is a time consuming operation that impacts the part's quality and manufacturing cost.
Not only would the manufacturer want to thread mill whenever the part is expensive, but they would also want to thread mill when working with a large hole diameter. Of course, a tap is just as large as the hole, so for a 4 in. thread diameter, a 4-in diameter tap is needed. Instead of buying this expensive, large piece of metal or storing taps for every thread size, the company could buy an off-the-shelf thread mill and interpolate the thread into multiple thread sizes including those large diameters. Lastly, thread mills consume significantly less power from a machine in the instance of large diameters.
Other advantages of thread mills include the ability to hold tight tolerances by controlling the tool's cutting path. As the tool shrinks slightly from wear, it is easy to compensate this at the machine by using tool diameter offsets.
Nevertheless, there are occasions where tapping may be the better choice over thread milling. For example, a user would want to use a tap when machining long lengths of thread. Due to the lack of radial load, there is no concern about the tap's stability or tool deflection. In addition, when speed is preferred over thread quality, taps are again the better choice. In many applications, a tap will have a shorter cycle time than a thread mill. However, this still comes with the risk of breaking the tap and spending valuable time to get it removed.
When to use solid carbide thread mills vs. indexable thread mills?
In choosing to thread mill, the user has the option of solid carbide or indexable thread mills for an application. This choice often comes down to the needs of the application in terms of quality, repeatability and flexibility.
Solid carbide thread mills
Quality and performance are key advantages of solid carbide thread mills. Solid carbide thread mills run and cut faster every time. Having a constant surface footage between two different diameters will result in a different RPM. Due to its smaller cutter diameter, solid carbide thread mills will run at a higher RPM. In combination with typically having more flutes, this will result in a faster penetration rate (in/min or mm/min) and improved cycle time. These tools typically outperform indexable thread mills in terms of quality because threads are being ground at the same time. This improves the consistency of threads. With a smaller cutter diameter, there is less contact with the workpiece, resulting in less heat generation and deflection as well.
Indexable thread mills
Most users are attracted to indexable thread mills because they provide the ability to change out thread forms frequently. The operator can take one body and change out inserts, and the machine is quickly up and running with different forms or pitches. Ultimately, this makes indexable thread mills better for low production batches as well as job shop type of work with a lot of change over and variation in the manufacturing. This again comes back to the flexibility of the tooling. Users can make a one-time purchase of the body and then switch over the inserts as needed.
All in all, a thread mill is simply milling a thread form and a pitch and can usually be used for both left and right-hand threads, internal or external, multiple start threads and various tolerances.
How does material impact a thread-milling application?
Material removal in threading is no different than any other manufacturing process like boring or turning. There are always two things to consider:
The first question can be answered by the thread's pitch. While a fine pitch does not require much material to be removed, a course pitch requires a lot of material to be removed. The combination of these two questions will also help to determine whether material can be removed in one pass or not. Regardless of how many passes is required to remove the material, just like with boring or turning, a finish pass can be used for improved quality. This is often referred to as a spring pass. If needed, users should refer to the technical section of a manufacturer's catalog or an available thread mill programming software like InstaCode to choose the right number of passes.
What are the best practices for programming?
As mentioned above, a thread mill can create a variety of threads like left or right-hand, internal or external by simply manipulating the program/tool path. Writing a program in incremental movements instead of absolute is always preferred. In doing so, users can insert code for the threading portion as a sub-program or sub-routine. This is beneficial when threading multiple holes because it provides a single place for program edits. This also allows users to quickly complete a test run above the part to prove out the program. In addition to writing this in incremental movements, an arc-on and arc-off movement will improve the quality of the thread and extend the life of the thread mill.
How to diagnose issues when thread milling?
Because thread mills have radial cutting forces, deflection should always be kept in mind. Factors mentioned previously like how much material is to be removed and what the material is like to machine can be battled by adjusting the number of passes to remove the material as well as the combination of speed and feed. Additionally, consider the tool holder being used. Because of the radial forces and potential deflection, it is necessary to use tool holders such as milling chucks, hydraulic chucks or shrink fits that minimize deflection. Ultimately, these tooling solutions are more rigid and, therefore, improve the quality of the thread being machined.
It is also necessary to understand if the programmed tool path is based off of the center of the thread mill or outer diameter of the thread mill. This changes how wear offsets should be applied in the machine.
While a user may encounter additional challenges when machining threads, asking these five questions aids in building the foundation for a successful application.
Many industries (Agriculture, aircraft, nuclear, construction, medical, mold& die etc.) need their workpiece components to be thread rolled for more strength.
Rolled threads produced on thread rolling machine supply many advantages:
All thread rolling machines are able to make both infeed and throughfeed
The standard thread rolling machines are plan to manufacturing as batch process mode, In the other hand, we have more then 10 units of quality thread grinding machines, and gear
grinding machines for the thread rolling die department.
Armpro offers a wide selection of products catering to different applications.
You will get efficient and thoughtful service from Yushi.
Armpro Sales and Tech team are available for the pre-sale consultation, after-sales service, on 24/7.
Armpro understands the demands it takes in the thread rolling industry and is committed to your business
Before delivery, all the machines needed to be checked and inspected fully for 48 hours.
We provide the combination of product and knowledge to enable you to maximize your investment
Armpro offers 2 years warranty for all metalworking machines that customers can be guaranteed a complete after-sale serviced.
Thread rolling is an efficient and cost-effective method for producing threads, as it can be done quickly and with minimal material waste. Apart from that, it also helps in strengthening the surface with more precise accuracy and minimizes material waste.
Did you know that more screw threads are produced each year than any other machine element? While there are many methods for threading in manufacturing such as casting, rolling, chasing, die-cutting, etc., not all of them are widely used anymore in the industry. As the industry has been getting more and more competitive over the years while available resources are also slowly depleting, a majority of manufacturers have opted for Die-cutting and Thread Rolling methods to maximize their production efficiency. Out of the pair, the Thread Rolling method stands out due to its low-cost high-quality finish, and a lot of industrialists are transitioning into incorporating this method even more.
Let us dig deeper to uncover more about Thread Rolling and how it stands out from the rest of the methods alongside its advantages and disadvantages in this ultimate buying guide to Thread Rolling Machines.
Thread Rolling is the process of forming threads on a metal stock by displacing the metal surface. The Thread Rolling process involves pressing a hardened tool, called a die, onto the surface of a workpiece to create the threads. It does not remove any excess metal from the piece like chips or shavings but simply uses more hardened steel to mold threads on a more ductile metal piece. This method does not severe the integrity of the metal form but simply elongates and reforms it to make it even stronger. Thread Rolling is typically used to produce threads on rods or bars, and it is capable of producing threads with high accuracy and surface finish.
It is a known fact that cold working helps strengthen most materials including metals alongside their fatigue resistance and hardness. Thread rolling is such a method that grants a ton of benefits for the manufacturers using this method. Apart from putting out a way stronger product, it also does the job with minimum wastage and the best-looking surface finish. In hindsight, Thread Rolling is a process of forming threads rather than cutting or carving them out like in older traditional methods and is way more accurate and economic.
Thread Rolling is a Thread forming method that does not cut or shave the surface to make threads but reforms and molds threads on it with applied pressure. It is a cold forging method meaning that squeezes the metal to form threads below its recrystallization temperature. It is not exactly a new technology and has been around for a very long time. However, the recent advancement in technology and the industry allowed this method to be precise and cost-effective for mass manufacturing only recently.
On the other hand, Thread Cutting involves using a cutting tool to remove material from the workpiece to create the threads. It is a subtractive method that outputs a considerable amount of chips or shavings in the process. This can be done with a single-point tool on a lathe or with a multi-point tool on a screw machine. Thread cutting is typically used to produce threads on bolts, screws, and other fasteners, and it is capable of producing threads with a wide range of thread profiles and pitches. Unlike the rolling method, Thread Cutting allows for the production of threads on a wider range of materials.
So to summarize the differences; thread rolling is a more efficient and cost-effective process than thread cutting, but thread cutting is more versatile and can be used on a wider range of metals.
Now that we have gone over what Thread Rolling is and how it generally functions, let us look into how this method holds up in mass manufacturing. Here are some advantages and disadvantages of the Thread Rolling method.
Advantages:
Disadvantages:
Thread Rolling is a superior method in thread manufacturing. However, due to its specialized process, there are a few factors to be considered in order to utilize this method:
There are 2 main Thread Rolling methods: Infeed Rolling and Through-feed (Thrufeed) Rolling. While almost all industrial thread rolling machines use these 2 methods, they differ when it comes to their use cases.
Infeed rolling method uses circular dies where the thread angle is equal in magnitude but opposite in direction. This method is also commonly referred to as the plunge method. The workpiece and the dies are placed parallel in this method and move in synchronization to form the threads. The main advantage of this method is the speed of the process, which makes it ideal for mass production. And machines that use this method come with 2 or 3 dies according to the specifications. However, the rolling is limited to the maximum length of the dies meaning that it is typically used for shorter threads and for parts with more complex shapes or profiles.
Thrufeed rolling method, on the other hand, is a continuous process where the part is fed through the machine, and the die rolls along the entire length of the part in a single pass. This method is more efficient in creating longer threads or larger quantities of parts. The dies in this process are usually placed at an angle the tilted Helix angle helps in the continuation of the rolling process, allowing for longer workpieces. Even though this method excels in managing much longer workpieces, it is typically limited to parts with simple shapes and profiles. The machines that use this method come with either Groove dies or Lead Corrected dies to fit the requirement of the work.
So in retrospection, both infeed rolling and thrufeed rolling can produce high-quality threads with good surface finish and dimensional accuracy. The choice between the two methods will depend on the specific requirements of the part and the thread being produced.
Thread rolling has a couple of special methods that cater to different scenarios and workpieces as mentioned above. So it is important to consider your requirements before proceeding with a Thread Rolling machine. There are several key factors to consider when purchasing a thread rolling machine for manufacturing threads:
Thread Rolling machines use hardened dies to press against the surface of the workpiece and form the threads. These dies are typically made of high-strength materials such as tool steel or tungsten carbide, which are able to withstand the high forces and wear associated with the thread rolling process. So metals such as steel, aluminum, brass, and copper are the ideal materials that can be used in common Thread Rolling processes due to their less intimidating properties when compared to the dies.
Other materials, such as plastics, can also be rolled to create threads, although the process is generally more limited and the materials may need to be treated or modified in some way to make them suitable for rolling. In general, the suitability of a material for thread rolling will depend on its strength, ductility, and other mechanical properties, as well as the type of thread being produced and the specific requirements of the application.
Thread Rolling is exclusively used to create threads on cylindrical parts and their application spreads across multiple industries. Thread rolling machines are an essential tool for the production of high-quality, accurately-dimensioned threads in a variety of industries. Some of the main applications of these machines include:
Thread rolling dies are usually made from high-strength materials such as tool steel or carbide, and are designed to withstand the high stresses and abrasive forces that are involved in the thread rolling process. There are several types of thread-rolling dies that are used in thread-rolling machines in the manufacturing of threads. These include:
We hope that this guide clears all your general questions regarding Thread Rolling in general and assists you in deciding the perfect thread-rolling machine for your business/factory. If you are also looking for a Gear Chamfering Machine, check out our detailed guide on How Gear Chamfering Works and how you should decide on which machine to buy.
If you want to learn more, please visit our website Thread Rolling Manufacturer.