When manufacturing combined screws, customers often express satisfaction with the quality of the product. But how can you truly assess whether a combination screw is of good quality? Below is an overview provided by the manufacturer of combination screws, Zhu:
The quality of a combination screw starts with the wire used in its production. The screw wire is the fundamental element that determines the overall quality. If the wire is substandard, even with advanced machinery and skilled workers, it's impossible to produce high-quality combination screws.
Secondly, the visual appearance of the combination screw is an important indicator of its quality. This includes the size and shape of the screw head, the flatness of the washer, and the thread's ability to pass through a stop gauge. All these aspects must be checked. A well-made combination screw should meet either national standards or specific customer requirements.
Finally, the plating color is another factor that reflects the quality of the combination screw. While iron combination screws typically require plating, stainless steel ones are usually passivated to improve their corrosion resistance. Poorly controlled plating can result in significant color variations, which may affect the aesthetic appeal.
**Matters to Consider When Installing High-Strength Bolts**
1. **Quality Considerations**
- Remove any surface rust, oil, burrs, or welding spatter from the bolt hole walls.
- After surface treatment, ensure the friction coefficient meets the required specifications. High-strength bolts must be used with matching nuts and washers.
- Avoid contamination of the treated friction surface with oil or dirt during installation.
- Keep the friction surface dry during installation and avoid using it in rainy conditions.
- Check and correct any deformation in the connected steel plates before installation.
- Do not hammer the bolt during installation to prevent damage to the threads.
- Regularly calibrate electric wrenches to ensure accurate torque and follow the correct tightening sequence.
2. **Safety Measures**
- Use an adjustable wrench that matches the nut size. Avoid using a small wrench with an extension. For high-altitude work, use a dead wrench and secure it with a rope if a spanner is needed.
- Never insert your hands into the connection surface or the bolt hole when assembling steel components. When handling horn plates, place your fingers on both sides.
**Overview of Locknut Features and Applications**
A nut is a mechanical component used to connect parts via internal threads. For example, an M4-0.7 nut only fits with an M4-0.7 screw (where "M4" refers to the inner diameter of about 4mm, and "0.7" indicates the distance between threads). Similarly, American products like a 1/4-20 nut only match a 1/4-20 screw (with an inner diameter of approximately 0.25 inches and 20 threads per inch).
The DISC-LOCK locknut consists of two parts with staggered cam surfaces. Its internal wedge design has a slope angle greater than the bolt’s nut angle, creating a tight grip under vibration. The convex parts of the locknut move apart, generating lifting tension to provide excellent anti-loosening performance.
**Key Features:**
- Easy to install
- Durable and compact
- No need for washers
- Easy to remove
- Reusable
- Made from medium carbon steel
- Compatible with high-strength bolts (8.8, 10.9)
- Passes US military MIL-STD 1312 Vibration Test 7
- Tested using Junker and Dynamic tests
**Applications:**
- Automotive (cars, trucks, buses)
- Compressors
- Construction equipment
- Wind turbines
- Agricultural machinery
- Foundry
- Drilling equipment
- Shipbuilding
- Military
- Mining equipment
- Oil rigs (onshore/offshore)
- Public infrastructure
- Rail systems
- Transmission systems
- Metallurgical equipment
- Rock hammers
**Rivet Nut and Its Characteristics**
A rivet nut, also known as a self-locking nut, is designed for use on thin metal sheets. It features embossing teeth and a guide groove at one end. During installation, the teeth are pressed into a pre-drilled hole in the sheet metal. The hole is slightly smaller than the rivet nut's teeth, so when pressure is applied, the nut is squeezed into the plate, causing plastic deformation around the hole and locking it in place.
Rivet nuts come in different types, such as fast-cut steel (S type), stainless steel (CLS and SP types), and copper/aluminum (CLA type), each suited for different environments. They are commonly available in sizes ranging from M2 to M12. There is no universal standard for rivet nuts, and they are widely used in chassis cabinets and sheet metal applications.
**Difference Between Screws and Bolts**
Screws and bolts serve different purposes. Screws are typically used to fasten fixed components and are easy to install and remove. They generally have lower strength compared to bolts. Bolts, on the other hand, are stronger and are often used in load-bearing applications, capable of withstanding larger forces.
In most cases, screws are screwed into threaded holes, while bolts are tightened with a nut. However, this is not absolute, and unconventional uses may still be valid if applied appropriately. Flexibility is key, but proper understanding of their roles ensures better performance and safety.
EDAWELD COMPANY LIMITED , https://www.jsedaweld.com