Custom Screws Manufacturer Shi Shi Tong, Building 9, Tantou First ，Industrial Zone, Songgang Street, Baoan, Shenzhen 518105, Guangdong Province, China, Shenzhen (2026)

09/07/2026

A 2000mm long screw — is it just about making it longer?

Many engineers think that producing a long screw is simply extending the length of a standard screw.

But in real applications, the challenge is far more complex.

When the screw length increases, problems such as shaft bending, thread accuracy deviation, forming difficulty, and installation stability become more critical. A small deformation during manufacturing may lead to assembly errors, vibration, or even equipment failure.

So, how can a long screw maintain the same reliability as a standard fastener?

The answer lies in the entire manufacturing process — from material selection, one-piece forming technology, precision machining, heat treatment, to strict quality inspection.

At Shi Shi Tong, we focus on customized long screws and non-standard fasteners for demanding industries. With experience in producing extra-long screws up to 2000mm, we help customers solve challenges in precision, strength, and reliability.

We don’t just manufacture a screw according to a drawing.

We work with customers to optimize the structure, select the right material, and provide a reliable fastening solution for their applications.

08/07/2026

Are the good non-standard screws and CNC parts factory only capable of generating products according to the requirements, or are they willing to provide you with optimized solutions that are even better?

In the actual processing of non-standard screws and CNC parts, have you ever encountered such a situation: the design drawings have been completed, but when it comes to the processing stage, it is discovered that the structure is unreasonable - the processing difficulty is high, the cost increases, the assembly risk is high, and even the performance of the final product is affected. And some suppliers merely "produce according to the drawings", lacking the ability to propose optimization suggestions from a manufacturing perspective.

Shi Shi Tong has always believed that non-standard screws and CNC part processing is not just about making a part; it is more about helping customers make their products more reliable and efficient.

In the early stages of the non-standard screws and CNC parts project, our engineering team will conduct an analysis from multiple perspectives including material selection, structural design, processing techniques, clamping methods, and subsequent assembly applications. This will enable us to identify potential issues for you in advance and propose optimization solutions. For instance, reducing unnecessary processing steps, optimizing the tool path design, lowering processing costs, while ensuring the part's accuracy and performance.

Shi Shi Tong is not merely concerned with a single order; rather, it focuses on whether your products can be successfully mass-produced and operate stably.

We are very eager to hear your opinion - whether it's better to simply generate according to the requirements or if you would be willing to offer optimization.

07/07/2026

Customized non-standard CNC parts, value goes beyond just processing.

Many customers believe that CNC processing is the process of turning blueprints into actual products.

However, in actual projects, the difficulties of a non-standard part often lie beyond the drawings: Is the material selection appropriate? Does the structure affect assembly? Does the processing accuracy meet the requirements for long-term operation?

We believe that non-standard CNC customization is not merely manufacturing; it is also an engineering collaboration.

From the initial communication, process analysis, to processing and production, as well as quality inspection, we have always been based on the customer's application scenarios. We help customers reduce risks. The factory has obtained ISO9001 certification and can provide PPAP and APQP test reports. The products have passed ROHS, SGS, and REACH certifications to enhance product reliability.

The value of a part does not lie in its mere manufacture, but in its ability to operate stably in the customer's equipment.

In the future, if you have requirements for complex CNC parts, special materials or high-precision parts, please feel free to contact us. Maybe next time, we can jointly find a better solution.

06/07/2026

How to Prevent Galling in Titanium Screws？

In precision industrial equipment, medical devices, unmanned aerial vehicle structures, and high-end industrial equipment, titanium alloy screws are widely used due to their lightweight, high specific strength, and excellent corrosion resistance, especially suitable for seawater, chemical media, and long-term service environments. However, in practical engineering applications, a frequent problem exists with titanium alloy screws - galling.

Galling of titanium alloy screws is not simply "over-tightening", but a typical adhesion and wear failure mechanism. When the threads are subjected to high contact stress and relative sliding, the few-nanometer-thick oxide film (TiO₂) on the titanium surface is destroyed, and the fresh metal is exposed, resulting in high-activity contact. Under the local pressure and friction heat, microscopic cold weld points are formed. Continued rotation tears these adhesion points and causes metal transfer, ultimately leading to the screw getting stuck.

From the perspective of material properties, the elastic modulus of TC4 titanium alloy is approximately 110 GPa, significantly lower than that of steel (about 200 GPa), making it more prone to local elastic deformation and concentrated contact stress when subjected to force. At the same time, its thermal conductivity is only about 6–7 W/m·K, approximately 1/5 of steel, resulting in friction heat that is less likely to diffuse, and more likely to form high-temperature zones at the microscopic contact points, thereby accelerating adhesion wear. Under dry friction conditions, the friction coefficient of titanium and titanium screw pairs is usually between 0.3–0.6, while using MoS₂ or anti-galling agents can reduce it to 0.05–0.1, with a direct difference determining whether it enters the adhesion critical state.

The core of preventing galling of titanium alloy screws lies in interrupting the "high stress + direct metal contact + relative sliding" chain of conditions. Firstly, in material pairing, titanium and titanium are the most dangerous combination, with a higher probability of galling than titanium and steel or titanium and aluminum systems. Secondly, in surface engineering, anodizing can enhance the stability of the oxide film, with a friction coefficient as low as 0.05–0.1 and hardness over 2000 HV for DLC coating, and TiN coating can increase the surface hardness to 2000–2500 HV, effectively inhibiting the formation of microscopic adhesion points.
The lubrication system of titanium alloy screws is also crucial. Anti-galling agents are not ordinary lubricants but form an isolation film on the screw thread surface through MoS₂ or nickel-based particles to prevent direct metal contact. In engineering tests, proper lubrication can reduce the risk of galling by more than 30% and significantly reduce torque fluctuations.

The assembly process of titanium alloy screws is also a key variable. The elastic modulus of titanium alloy is lower, making it more sensitive to torque changes. High-speed electric screwdrivers can easily cause local instantaneous friction heating during locking, so it is recommended to use low speed, torque control, or torque + angle control to avoid local overload of titanium alloy screws. At the same time, dry assembly should be avoided as initial micro-damage can destroy the oxide film, laying a hidden danger for subsequent galling.

At the design level of titanium alloy screws, coarser pitch threads are less prone to galling than fine-threaded ones because the unit contact area and friction energy are lower; reasonable control of the thread meshing length also helps to reduce the risk.
Essentially, galling of titanium alloy screws is not a random failure but the result of an energy imbalance. When high contact stress, no isolation film, and relative sliding all exist simultaneously, adhesive wear is almost inevitable. Therefore, all engineering measures - material combination, coating, lubrication, and assembly control - are essentially blocking this energy path.

In practical applications, titanium screws with a complete engineering system optimized by Shi Shi Tong (such as PVD coating + anti-galling agent + controlled torque assembly) can maintain stable performance even after tens of assemblies, while untreated titanium alloy screws may become stuck after 2–3 assemblies. This difference is not a material issue but a problem of system design integrity.

When providing titanium alloy screw solutions to customers, Shi Shi Tong does not merely supply the products; instead, it conducts overall control from material matching, surface engineering to assembly processes to reduce the risk of seizing. Firstly, in the material selection stage, it is advisable to avoid pairing titanium with direct titanium threads, as this is the combination with the highest risk of seizing. Under the permitted structural conditions, it is preferable to use a combination of titanium and surface-treated stainless steel or aluminum alloy nuts, thereby reducing the tendency of intermetallic adhesion from the source. If a fully titanium structure is necessary, a higher-level surface coating needs to be used for compensation.

Secondly, on the coating of titanium alloy screws, anti-seizing measures should be standardized. Common effective methods include PVD coating, electroless nickel coating, and anodizing treatment, which can significantly increase the surface hardness and reduce the friction coefficient, transforming the screw contact from "metal direct contact" to "low adhesion interface contact". At the same time, before assembly, a stable isolation film should be uniformly formed on the screw threads using MoS₂ or nickel-based anti-seizing agents, reducing the friction coefficient from 0.3–0.6 to a safe range of 0.05–0.15.

In terms of the assembly process control of titanium alloy screws, the torque window needs to be strictly controlled, and low-speed tightening or torque + angle control methods should be prioritized to avoid instantaneous friction heating and local overload caused by high-speed electric tools. At the same time, the on-site operation procedures should be standardized, and dry assembly trials or repeated un-lubricated insertion should be prohibited, as initial microscopic scratches are often the starting point of subsequent seizing.

If you encounter problems with titanium alloy screws, please feel free to send us the drawings, samples or application requirements of titanium alloy screws. We are willing to work with you to solve the problems, covering aspects such as material selection, structural optimization, surface treatment and testing requirements.

05/07/2026

A "small screw" may seem insignificant in a device, but it can determine the overall stability of the entire machine.

In precision equipment, the space is getting increasingly limited and the structure is becoming more and more complex. In many cases, the real challenge is not "can it be installed", but:
After long-term vibration, temperature changes, and repeated disassembly and assembly, can it still maintain its position unchanged.

A suitable small screw requires more than just a matching size; it also needs to consider factors such as:

Stable preload retention capability
Anti-fretting wear resistance
Reliable consistency after long-term repeated assembly
Compatibility with material systems

When we are dealing with non-standard fasteners, we often encounter situations where the customers redefine their requirements：it's not "I want a screw", but "I want this position to always function properly".

And this is precisely the true value of the small screws.
It may not be conspicuous, but it determines whether the system is reliable.

04/07/2026

Titanium vs Stainless Steel Screws in UAV Applications

During the development of unmanned aerial vehicles (UAVs), many teams focus on flight control, motors, batteries, and weight reduction of the fuselage. However, what truly determines the long-term reliability of a device often involves those seemingly insignificant titanium screws and stainless steel screws. Many people believe that titanium screws are lighter and more expensive, so they must be better; others think that stainless steel screws are mature and stable, sufficient for most applications. In fact, in engineering design, this is not a simple matter of material selection.
The real question to be answered is not which material is better, but which material's non-standard screws are more suitable for your product.

Take the most common Ti-6Al-4V (TC4/Grade 5) in the UAV industry as an example. Its density is approximately 4.43 g/cm³, which is about 40% to 45% lighter than the density of 304 or 316 stainless steel, which is approximately 7.9 to 8.0 g/cm³. Therefore, it has a significant weight reduction advantage in long-duration UAVs, VTOL aircraft, and high-performance racing UAVs. Additionally, TC4 has an average tensile strength of 895 to 930 MPa and a yield strength of about 825 to 880 MPa, with very excellent specific strength. But materials always have two sides. The elastic modulus of TC4 is approximately 114 GPa, significantly lower than the 190 to 200 GPa of stainless steel, meaning it will undergo greater elastic deformation under the same load; moreover, titanium alloy screws need to pay attention to the risk of thread locking (Galling), so during assembly, reasonable surface treatment, lubrication methods, and locking processes are usually required. If only a few grams of weight are to be reduced by choosing titanium alloy screws, but the structural design and actual working conditions are ignored, it may not be the best solution.

In contrast, stainless steel remains one of the most widely used materials in the UAV industry. 304 and 316 stainless steel have excellent corrosion resistance and tensile strength typically ranging from 515 to 620 MPa, suitable for most structural connections; if the equipment requires higher strength, many engineers will choose 17-4PH or A286. Among them, 17-4PH, after hardening treatment, can reach tensile strengths of 1000 to 1300 MPa while maintaining good corrosion resistance and dimensional stability, thus often used in gimbal mechanisms, precision brackets, and load-bearing components; A286 also combines high strength, good fatigue resistance, and high-temperature resistance, and is very common in long-term vibration, high-cycle load, and aerospace fasteners. Therefore, what truly determines the material selection is not the material price, but what function the non-standard screws in the entire machine perform and what working environment they need to face.

Therefore, when customers ask us which material to choose for non-standard screws, we usually do not directly answer "titanium alloy" or "stainless steel", but hope to first consult the drawings. Because material selection cannot be separated from the product itself. Only by understanding what function this non-standard screw is performing and what working environment it needs to face can we make an informed decision.

For example, folding UAVs need to maintain the consistency of the arm position during each unfolding, folding, and flight process. Therefore, the folding hinge shaft not only needs to withstand continuous vibration and cyclic loads but also needs to consider positioning accuracy and wear resistance.

Many designs initially use standard bolts as hinge shafts because they are convenient to purchase and have lower costs. But as the number of flights increases, engineers often find that the hinge gap gradually widens, the positioning consistency after unfolding decreases, and in severe cases, the arm may slightly shift, affecting flight stability and subsequent maintenance. Therefore, in such structures, we prefer to use custom non-standard screws such as shoulder screws. The shoulder part is responsible for rotation and positioning, while the threaded part is responsible for locking, enabling a single screw to perform both the rotating shaft and connection functions. For drones with high requirements for lightweight, TC4 (Ti-6Al-4V) material is usually chosen, with a density of approximately 4.43 g/cm³. Compared to stainless steel with a density of about 7.9-8.0 g/cm³, it can reduce the weight by approximately 44%, while the tensile strength can reach 895-930 MPa. If combined with solid lubrication coating and the customized shoulder length for the hinge thickness, it not only reduces friction and wear but also enhances the service life and repetitive positioning stability of the folding mechanism.

If the customer has not yet determined the material for the non-standard screws, there is no need to worry. You only need to provide product drawings, samples, assembly photos, or tell us the working environment, load conditions, service life, and performance requirements of the product. We can conduct a comprehensive assessment based on the mechanical properties, weight, corrosion resistance, processing technology, cost, and maintenance of different materials, and assist you in choosing a more suitable material, rather than directly recommending a more expensive or common solution.

At the same time, according to the project requirements, Sh*titong can also provide:
Dimension and tolerance inspection: thread go-no-go gauge inspection (GO/NO GO gauge)
Head diameter/thickness deviation (±0.05mm) total length tolerance (such as M6 screws ±0.2mm)
Tensile strength (ISO 898-1): 8.8 grade: ≥800MPa | 12.9 grade: ≥1220MPa
Hardness test (HRC/HV): 8.8 grade: HRC 22-32 | 12.9 grade: HRC 39-44
Torque test: failure torque ≥ 90% of the nominal value (such as M6 8.8 grade screws ≥ 10Nm)
Salt spray test (ASTM B117): Dacromet: 1000h without rust
Metallographic structure analysis: 8.8 grade screws: tempered sorbite (observed under a 500x microscope) | 12.9 grade screws: prohibited untempered martensite (to prevent brittle fracture)
Environmental adaptability: high and low temperature cycling (-40℃~120℃, 20 cycles after the thread does not deform)

Non-standard screws not only need to be processed, but also need to meet the quality requirements for subsequent verification and mass production.

What the customer truly needs is not a factory that can produce non-standard screws, but an engineering partner who can discuss the design of the drone solution together. Instead of asking "How much is this non-standard screw?", we would rather hear the customer say: "Here is our non-standard screw drawing. Can you help us review if there are any more suitable materials, structures, surface treatments, and inspection schemes?" 。 A truly suitable non-standard screw for the product is not made of the most expensive material, but is the result of the most reasonable engineering choice after a thorough understanding of the product structure.

If you are developing a drone project, please send us the non-standard screw drawings, samples or application requirements. We are willing to work with you to complete this engineering judgment, covering material selection, structural optimization, surface treatment and testing requirements.

03/07/2026

What kind of non-standard screw enterprise can win the trust of both employees and customers?

The core competitiveness of an enterprise is not merely about exquisite product craftsmanship; it lies in the meticulous attention to details and the efficient ex*****on of tasks. Amazon's founder, one of the world's top entrepreneurs, Jeff Bezos, once said this: "Excellent companies make profits, while great companies win people's hearts." As a supplier of high-reliability non-standard screw solutions, Shi Shi Tong Metal Products Co., Ltd. fully agrees: Treating employees well is the foundation for an enterprise to win people's hearts; efficient delivery is the original intention to repay customers' trust.

In July, a heartwarming company-wide health check-up event provided a vivid illustration of this corporate culture and service philosophy.

Previously, when our company's General Manager Xie was traveling to visit and learn from other enterprises, he noticed a heartwarming scene where the company organized a group health check-up for its employees. After further investigation, he learned that this company had found a hospital that could provide on-site health check-ups and regularly conducted health screenings for the employees, providing comprehensive protection for their physical health. This way, every hardworking employee could be cherished by the company with care.

This people-oriented principle deeply touched Mr. Xie. Immediately, he took the initiative to contact and obtain the contact information of the medical examination institution, and quickly settled the matter of the group's medical examination.

Adhering to the style of making decisive decisions and implementing them immediately, the medical staff were arranged to visit the site on the same day. However, due to the full schedule of the medical examination institution and the fact that many enterprises had made appointments and queued up in advance, the professional medical team successfully entered the factory on the third day after the connection was completed, and conducted comprehensive health check-ups for all on-site employees.
While Shi Shi Tong Metal has always adhered to this decisive decision-making, immediate ex*****on, and solid implementation style throughout the entire process of product customization, production, and delivery. From customer consultation, scheme coordination, drawing confirmation, sample production and trial production to mass production and timely delivery, we have abandoned cumbersome procedures and refused sluggish and inefficient practices. With agile responses, rigorous craftsmanship, and reliable performance capabilities, we strive to shorten the customer waiting period, helping customers quickly finalize cooperation, advance projects, and achieve production, saving time costs for customers and improving cooperation efficiency.

Treat employees well internally to build a cohesive team spirit; externally, uphold the craftsmanship and fulfill the trust of customers.

In the future, Shi Shi Tong Metal will continue to build the foundation of the company with humanistic values, and empower each cooperation with efficient strength. With reliable quality, efficient response and stable delivery, we will make every custom screw perfect and serve every partner well. Whether it's an urgent order for non-standard screw samples or a technical breakthrough for batch customization, we will spare no effort and become your reliable supplier of high-reliability non-standard screw solutions.

02/07/2026

Regarding the role of non-standard screws in high-end automation systems, most discussions focus on material strength, size specifications, or cost control.

Based on our experience, these are not the key criteria that determine whether the equipment can operate stably for a long time.

The real challenge lies in maintaining the microscopic stability and repetitive positioning accuracy of the connection points in an environment characterized by continuous vibration, frequent start-stop operations, and multi-system collaboration.

We would really like to hear your understanding of this: In your equipment design, how do you balance the structural design, the fastening scheme and the long-term stability?

02/07/2026

Many CNC parts may seem to be "just processed", but what truly determines their stability is often not the processing itself, but rather the understanding of the materials, stress release, and the design of the reference points in the early stages.

In some long-running equipment, the more common problem we encounter is not "inconsistent size", but rather:

After repeated assembly, vibration, or thermal cycling, minute deformations gradually accumulate and eventually lead to positional deviations or changes in clearance.

The value of CNC lies precisely here – it is not merely about "cutting and shaping", but rather a way to firmly implement the design intentions, and to eliminate uncontrollable factors as much as possible before they occur.

Sometimes, the best collaboration begins with a simple conversation.

Please feel free to contact us at any time to obtain the product catalogue, discuss OEM/ODM matters or arrange a factory visit.

01/07/2026

What determines the reliability of stainless steel screws in harsh environments?

When choosing materials for non-standard stainless steel screws, have you ever encountered such a question: "Should I choose 316L or A286?"

316L stainless steel
In chloride ion environments, coastal areas, chemical and food equipment, its advantages are quite clear:

Stable corrosion resistance + reliable performance at normal temperatures.
Many "chronic failures" actually result from the material's long-term exposure to the wrong environment, rather than a temporary lack of strength.

A286 stainless steel
When the application is subjected to high temperatures and high stresses, such as in aviation, gas turbines, or high-temperature structural components, the issue becomes:

Can the material still maintain structural stability and strength retention capabilities?
In such scenarios, the temperature resistance performance is often more crucial than corrosion resistance.

However, in the non-standard stainless steel screws projects we encounter on a daily basis, the real challenge usually does not lie in "choosing between 316L or A286", but rather in:

The description of the customer's working conditions is often fragmented.
Corrosion, temperature, and load occur simultaneously.
Failure usually occurs at the "neglected boundary condition".

Therefore, the selection of non-standard stainless steel screws is more like making a comprehensive judgment rather than simply relying on a material comparison table.

In the non-standard stainless steel screw project, our main focus is:

The actual boundaries of the operating environment (temperature/medium/pulsating load)

The possibility of failure paths (corrosion, creep, loosening)

And the overall stability of the non-standard screw connection structure, rather than the parameters of a single screw

The mission of this non-standard stainless steel screw solution is not to "provide a screw", but to re-examine the material selection within the framework of systems engineering. Committed to providing customers with professional non-standard stainless steel screw solutions.

Custom Screws Manufacturer Shi Shi Tong

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