As a common mechanical connection structure, the manufacturing accuracy of threads directly affects the reliability
and stability of the connection. This paper will analyze several common thread manufacturing techniques and discuss
the impact of different processing methods on thread accuracy.
I. Thread Turning
1. Working Principle: A thread is formed by cutting a helical groove on a rotating workpiece with a turning tool.
Thread turning is an efficient and commonly used method for thread processing, especially suitable for
external thread machining.
2. Factors Affecting Precision: The geometry of the turning tool, the precision of the machine tool, and cutting
parameters all influence the accuracy of the thread. For instance, the shape and angle of the tool tip affect the
accuracy of the thread profile, and the vibration of the machine tool affects the surface roughness of the thread.
3. Scope of application: It is applicable to the processing of external threads of various materials, especially for
mass production.
II. Thread Milling
1. Working Principle: Use a thread milling cutter to mill threads on the workpiece. The teeth of the thread milling
cutter are arranged in a spiral pattern, enabling the complete formation of a thread in a single operation.
2. Factors Affecting Precision: The accuracy of the milling cutter, the rigidity of the machine tool, and the cutting
parameters all influence the precision of the thread. For instance, the error in the helix angle of the milling cutter
will affect the pitch accuracy of the thread, and the vibration of the machine tool will impact the surface quality
of the thread.
3. Application scope: Applicable to the processing of internal and external threads, as well as some special-shaped
threads, such as conical threads and multi-head threads, etc.
III. Thread Drilling
1. Working Principle: Using a tap, internal threads are cut on the pre-drilled workpiece. Thread drilling is a simple
and rapid method for manufacturing internal threads.
2. Factors Affecting Precision: The accuracy of the tap, the properties of the workpiece material, and the stability of the
tapping machine all influence the precision of the thread. For instance, the diameter error of the tap will affect the
mating accuracy of the thread, and the hardness of the workpiece material will affect the surface quality of the thread.
3. Application scope: Suitable for the processing of small and medium-sized internal threads, especially for
mass production.
IV. Thread Rolling
1. Working Principle: Using a rolling die, threads are rolled onto the surface of the workpiece. Thread rolling
is a chipless processing method, which can enhance the strength and surface quality of the threads.
2. Factors Affecting Precision: The accuracy of the rolling die, the properties of the workpiece material,
and the pressure of the rolling machine all influence the precision of the thread. For instance, the tooth accuracy
of the die directly affects the tooth accuracy of the thread, and the plastic deformation ability of the workpiece
material affects the dimensional accuracy of the thread.
3. Application scope: Applicable to materials with good plasticity, such as low-carbon steel, aluminum alloys, etc.
It can be used to process high-strength and high-precision threads.
V. Thread Grinding
1. Working Principle: Thread is ground using a grinding wheel. Thread grinding is a highly precise method
for manufacturing threads and can be used to process materials with high hardness.
2. Factors Affecting Precision: The grit size of the grinding wheel, the grinding parameters, and the accuracy of
the machine tool all influence the precision of the thread. For instance, the grit size of the grinding wheel affects
the surface roughness of the thread, and the grinding speed affects the precision and surface quality of the thread.
3. Application scope: Suitable for processing high-precision and high-hardness threads, such as those of
hardened steel, tool steel, and other materials.
Here are the questions you might be interested in and their answers:
Q: How to choose the appropriate method for thread processing?
A: It needs to be considered comprehensively based on factors such as the type of thread, precision requirements,
material of the workpiece, and production batch size.
Q: How can the processing accuracy of threads be improved?
A: Choosing the appropriate processing method, using high-precision tools, optimizing cutting parameters,
and controlling the vibration of the machine tool can all improve the processing accuracy of the threads.
Q: How to check the accuracy of the thread?
A: Tools such as thread gauges and three-coordinate measuring machines can be used to check
the accuracy of the thread.
Different manufacturing techniques for threads have their own characteristics and applicable scopes.
Choosing the appropriate processing method and controlling various influencing factors can help produce
high-quality threads that meet the precision requirements.
