How does a thread rolling machine work?

1. The working principle of the thread rolling machine:

Thread rolling is a cold working process in which the machined blank is compressed between rotating or reciprocating dies and its thread profile is ground into the die. When the blank cylinder is penetrated by the mold, the metal flows into the mold cavity and forms a threaded profile in the part.

2. Advantages and disadvantages of thread rolling

There are many advantages and disadvantages to using rolled screw mill products. The main advantage of thread rolling is the greater surface and dimensional accuracy of the product. However, since the process is based on the principle of metal deformation, it is limited to soft metals and requires more expensive tools.

The advantages of using rolled screws and bolts are listed below:

• High thread strength: Thread rolling is usually performed at relatively low temperatures, making it a cold working process. Cold working is known to produce parts with higher strength without the need for secondary heat treatment. This makes rolling suitable for threaded materials that do not respond to heat treatment. Rolled threads are 10% to 20% stronger than cut or ground threads.

• Good surface finish: The thread rolling process itself imparts smooth and polished threads without the need for a secondary polishing process. The high compressive force that deforms the metal eliminates any unevenness in the threaded surface. The surface roughness of the rolled surface is about 8 to 24 microinch Ra, while the cut threads typically have 64 to 125 microinch Ra. The rolling line was also free of tears, chatter marks, cut marks and burrs.

• Precision Threads: Because the die used in thread rolling is a mirror image of the thread to be produced, and material is not removed from the stock, this process produces high-precision and high-precision parts over a long period of time. This is true if the mold is accurate and has sufficient hardness.

• Lower coefficient of friction: A good surface finish results in a lower coefficient of friction. A lower coefficient of friction provides a more even and consistent tightening of nuts and bolts, or better power transmission for leadscrews.

• Lower production lead time: Thread rolling is generally faster than thread cutting. The rolling speed depends on the type of material, the thread profile, the size and capacity of the machine, and the method of feeding the metal stock. For reciprocating dies, thread rolling can produce 30 to 40 parts per minute with blank diameters ranging from 5/8 to 1 1/8. For cylindrical molds, sizes 1 to 1 ½ inches, 10 to 30 parts per minute.

• Lower costs due to efficient use of material: Because thread rolling is a texturing process, not much material is removed during the entire machining process. Better use of energy is possible because there is no need to collect and recycle waste materials.

The following are the disadvantages of rolling:

It can be seen that these mainly affect the manufacturer rather than the end user. Ultimately, these add to the cost of the product, making rolled threaded products more expensive in some cases than products produced by other processes.

• Not practical for hard materials: thread rolling is mainly done on malleable metals. Although possible, thread rolling is not performed on metals above Rockwell 40. Beyond this hardness level, thread grinding is more practical. Rolling hard materials can significantly reduce tool life.

• More expensive tools: The dies used for rolling must be hard and precise. Any deformation of the mold will result in poor dimensional accuracy of the thread. Precisely making molds is difficult due to the required hardness.

• The blank diameter must be precise: there must be the right amount of material flow to displace and lift above the original surface. The diameter of the blank must be calculated and verified experimentally, especially when producing precise threads. In order to obtain the correct diameter, the stock may require a preliminary turning process.

3. Thread rolling application

At YTMTOOLS, we specialize in the production of threaded rolled parts for a variety of industrial applications. Our components can be used in factory applications, equipment, and commercial or residential environments.

Some of the most popular applications for threaded rolled parts include:

aerospace parts

car parts

Oil and Gas Parts

medical parts

plumbing accessories

fasteners

Accessories

fluid connector

HVAC Components

4. Thread rolling machine recommendation

5. Thread rolling machine video recommendation

YTMTOOLS Hydraulic Thread Rolling Machine