Do you need precise threaded rods for your upcoming project? Then threaded rod machining is your answer. This process involves adding helical threads to cylindrical bars by cutting, rolling or forming. This process produces mechanical parts and custom fasteners.
In this blogpost we will cover materials, machining techniques, tooling and the full process needed to make high quality threaded rods.
What is Threaded Rod Machining?
In simple terms, threaded rod machining means producing long metal rods with helical threads running the entire length. People often refer to these rods as all-thread or studs. Usually stainless steel, brass or aluminum are used to make them. These rods perform an important part in construction, automotive and industrial projects by securely joining different components.
Types of Threads in Threaded Rod Machining
In threaded rods machining, several types of thread can be used. Each type meets different needs. The most commonly used options are:
Metric
The most widely used thread type around the world having a 60 degree thread profile are metric threads. They are based on ISO standards and are measured in millimeters.
Generally metric sizes start at M1 and go up to M68. Pitches range from 0.25 mm to 6 mm. Many people choose metric threads because of their global compatibility and accuracy.
Acme
Acme threads feature a trapezoidal profile with 29 degree thread angle. For power transmission and lead screw applications this design is very useful. Inch based measurements are used, with common pitches of 10 TPI for ½ inch rods. Acme threads provide smooth operation and strong performance. That’s why for demanding and heavy duty uses, they are preferred.
Unified
Unified threads also possess 60 degree V shaped threads (like metric threads) but are measured in inches and follow the Unified Thread Standard (UTS). The main series include UNF (fine), UNC (coarse) and UNEF (extra fine). In North America, these threads are very common. Mostly they are found in machinery and construction projects.
RICHCONN’s fabrication and CNC machining services can produce unified, metric or acme threaded rods to match your exact needs.
Materials and Grades
Threaded rods come in different metal options. Each metal is suitable for certain environment and load requirements. The below table lists common materials & their grades.
| Material & Grade | Common Grade | Common Use | Main Properties |
|---|---|---|---|
| Low Carbon Steel | A307 | General construction | Moderate strength, cost effective |
| Medium Carbon Steel | SAE J429 Grade 8 | Automotive, machinery | Higher strength, heat treated |
| 304 Stainless Steel | B8 | Corrosive, marine environment | Durable, corrosion resistant |
| Alloy Steel | ASTM A193 B7 | High stress, pressure vessels | Heat resistant, high tensile |
| Aluminum, Brass, Nylon | Electrical, lightweight use | Corrosion resistant, non magnetic |
Standard sizes and pitch
To meet different engineering needs threaded rods are available in many sizes. Popular metric sizes and their standard pitches are given in the following table.
| Size | Coarse Pitch (mm) |
|---|---|
| M6 | 1.00 |
| M8 | 1.25 |
| M10 | 1.50 |
| M12 | 1.75 |
| M16 | 2.00 |
| M20 | 3.00 |
RICHCONN provides threaded rods in many materials such as plastics, specialty alloys and carbon fiber. You can always select the right option for your application and industry.
Manufacturing Methods
There are different methods available for making threaded rods. Each method is suited to different project needs and production volumes. By knowing these options you can select the most suitable process.
Thread Rolling vs Cutting
High volume production often relies on thread rolling. In this method, hardened dies are used which press threads into the rod. This action strengthens the metal and produces threads that are both precise and smooth.
Whereas in thread cutting, tools such as taps or lathes are used which remove material and form threads. For custom orders or when the material is harder or has a larger diameter, this method works best.
RICHCONN has expertise in both thread cutting and rolling. Whether you need large quantities or a small batch of specialized parts, we can suggest and provide the right method for your needs.
Forming Methods
In forming processes, like radial‐die and flat‐die thread rolling, threads are shaped by deforming the rod’s surface. During this process, no material is removed. Threads made this way have better surface finish and higher strength which is useful for demanding uses.
Subtractive Methods
Turning, grinding, milling and tapping are all subtractive techniques. In all these processes, a cutting tool is used which removes material and generates threads. For both internal and external threads, they are useful. Mostly these methods are used for complex shapes or when producing small quantities.
Also See: A Complete Guide to CNC Milling
Additive Variants
Additive techniques such as 3D printing create threads as part of the building process. For making complicated designs that traditional manufacturing cannot handle, these methods are useful.
Machining Threaded Rod – Process Flow
In threaded rod machining many steps are involved that maintain both precision and strength. Here is an overview of the main steps.
Pre machining Setup
In the first step, a suitable raw material is selected like carbon steel or stainless steel. Operators then use automated shears and saws to cut the rods to the needed length.
Threading Workflows
The next stage is threading which can be done by rolling or cutting. In rolling, threads are formed by pressing dies into the rod which keeps the material strong. Cutting shapes the threads by removing material. In both approaches careful control of depth and pitch is necessary to obtain high quality threads.
Finishing
The rods are then cleaned to eliminate debris or oils. Surface smoothness and appearance improve with polishing or tumbling. For corrosion protection, galvanization or coating is often added, particularly for rods used outdoors.
RICHCONN provides a complete set of in house surface finishing services. Your parts arrive ready for assembly which reduces extra logistics and saves time.
Secondary Operations
For some rods, extra steps are needed such as drilling holes or machining grooves to meet specific needs. Moreover before packaging each rod is also checked for quality and accuracy.
Equipment and Tooling
For machining threaded rods efficiently and accurately, special equipment and tools are needed. Some common tools are
- Thread rolling machines that use hydraulic power to press dies onto rods and form strong threads.
- Thread cutters have heat treated jaws that cut threads cleanly without causing damage.
- For high precision cutting and finishing, thread grinders and CNC lathes are used.
- Chamfering machines remove burrs and prepare the ends of rods.
These tools can handle different thread types and materials. As a result you get consistent quality in both custom and high volume production.
Parameters, Speeds and Feeds
It is very important to choose the correct parameters for accurate thread machining. Feed rate, spindle speed and depth of cut are the main factors.
Set the feed rate equal to the thread pitch when turning threads. For instance use a feed rate of 1.5 mm per revolution to machine an M10x1.5 thread.
The material’s cutting speed and rod diameter determine the spindle speed. For an M10x1.5 thread with a cutting speed of 60 meters per minute and a 10 mm rod diameter, set the spindle speed to about 1900 RPM.
Material type also affects these settings. For harder materials such as stainless steel, slower spindle speeds are needed. Whereas softer metals like aluminum need higher speeds. Always match your spindle speed and feed settings carefully. This prevents pitch errors and guarantees high thread quality.
If you need help optimizing these parameters for a specific thread or material, our engineers at RICHCONN can assist with process adjustments and troubleshooting.
Also See: What is Feed Rate and Cutting Speed in CNC Machining
The Main Application of the Threaded Rod
Construction
Threaded rods are used in construction projects to anchor structural parts, suspend heavy machinery and support frames. Workers embed these rods in steel or concrete to create adjustable, strong joints. For buildings, bridges and major infrastructure, they are suitable because they can handle heavy loads.
Medical
Medical devices rely on threaded rods in lab equipment, imaging machines and surgical robots. To ensure accuracy and hygiene, these rods must be corrosion resistant and meet tight tolerances.
In patient monitors and MRI systems, stainless steel rods are mostly used because they are dependable and easy to sterilize.
Aerospace
For aerospace applications, threaded rods help assemble aircraft frames, fasten essential parts and hold engine mounts in place. Mostly stainless steel or titanium rods are used because of their durability and light nature. These materials help the rods resist pressure and vibration, thus keeping flights reliable and safe.
Lead Screws
Lead screws are a type of threaded rod which changes rotational motion into straight line movement. In linear actuators, machine tools and automated devices, they are mostly used. These screws control precise movements in lab tools and pumps. This enables accurate fluid delivery and sample processing.
In electrical, automotive and manufacturing industries, they are also used. Their wide range of uses shows how important they are in modern engineering.
Advantages of Threaded Rod Machining
Stronger
Machined threaded rods provide outstanding strength. Compared to cut threads, rolled threads deliver up to 20% more strength. This guarantees dependable load bearing in critical uses. Both stainless and high strength steel options can handle heavy loads and resist deformation even when stressed.
Flexible
Flexibility serves as a major benefit. You can cut threaded rods to custom lengths. Moreover they are available in various diameter sizes from M1.0 to M68. For projects with special size or threading needs, this range is very helpful.
Economical for Volume
Large production runs benefit from the cost effectiveness of threaded rod machining. For example thread rolling helps lower waste and increases production speed. Compared to cutting, this method can reduce costs by over 15%.
Precise for Low Volume
CNC thread machining provides high precision for custom work or small batches. Tolerances often reach ±0.01 mm. For assemblies where repeatability and fit are important, this level of accuracy matters most such as in aerospace or medical devices.
Also See: A Complete Guide to Low Volume Manufacturing
To Sum Up
In short, threaded rod machining meets the needs of demanding industries by utilizing advanced techniques, accurate equipment and robust materials. The process provides flexibility, high strength and cost savings. Machined threaded rods continue to perform an important part in aerospace, construction and custom manufacturing.
If you need any type of custom threaded rods or other CNC machining services then Richconn is your best option. You can contact us anytime.
Related Questions
1. Is it possible to machine threaded rods with custom thread profiles for unique uses?
Yes threaded rods can be produced with custom thread profiles. For unique or non standard applications, CNC machines, specialized lathes or grinding equipment are used.
2. How do right hand and left hand threaded rods differ?
Right hand threads are tightened by turning clockwise; whereas left hand threads need a counterclockwise turn to tighten. In applications like bicycle pedals left hand threads are used to prevent loosening from rotation.
3. In what ways do temperature and environmental conditions impact machining tolerances for threaded rods?
Thermal expansion from temperature changes affects both the machine and workpiece. These shifts can cause deviations in tolerances and reduce machining precision.
4. Which standards or certifications must precision machined threaded rods meet?
Generally standards such as ASTM B211/B221, ISO 9001, DIN 975, and ISO 68-1 are needed. For aerospace parts, certifications like NADCAP or AS9100 guarantee quality control.
5. Can manufacturers use reverse engineering to duplicate old or discontinued threaded rod designs?
Yes they can use reverse engineering methods like silicone casting, 3D scanning or manual measurement. These methods allow accurate duplication of legacy threaded rod designs even without original drawings.
6. What impact does vibration during machining have on the thread quality of long rods?
Vibration may lead to chatter, distorted thread forms and lower surface finish. To keep thread quality high in long rods, use damping techniques and proper fixturing.
7. Which software solutions are recommended for CNC programming of custom thread profiles?
For CNC programming custom threads, GibbsCAM and Mastercam are popular choices. Advanced CAM & CAD software which supports simulation and custom toolpaths also works well.
