Question 1

Kesternich test

Accepted Answer

The Kesternich test is a type of corrosion test that is similar to the salt spray test, but it is specifically designed to evaluate the resistance of materials and coatings to acidic environments.

The Kesternich test involves subjecting test specimens to a controlled atmosphere of sulfur dioxide gas, which is combined with water vapor to create an acidic solution. The test is conducted in a chamber that is sealed and maintained at a specific temperature and humidity level. The acidic solution is continuously circulated through the chamber, exposing the test specimens to the acidic environment.

The Kesternich test is widely used in industries that require high levels of corrosion resistance in acidic environments, such as the chemical, pharmaceutical, and automotive industries. It is also used to test the quality of coatings, such as paints, varnishes, and platings.

The results of the Kesternich test are expressed in terms of the test duration and the degree of corrosion observed on the test specimens. The test is a valuable tool for evaluating the corrosion resistance of materials and coatings to acidic environments, but like the salt spray test, it is important to note that it is a laboratory test and may not necessarily reflect the actual performance of a material or coating in real-world environments.

Question 2

Salt spary test(SST)

Accepted Answer

The salt spray test, also known as the salt fog test, is a corrosion test method used to evaluate the corrosion resistance of materials and coatings. It is a standardized test method that involves subjecting test specimens to a continuous spray of saltwater mist in a controlled environment, usually at elevated temperatures. The test is designed to simulate the effects of saltwater exposure on a material or coating in a short period of time, typically between 24 to 96 hours.

The salt spray test is widely used in industries that require high levels of corrosion resistance, such as the automotive, aerospace, and marine industries. It is also used to test the quality of surface coatings, including paints, powder coatings, and platings.

During the test, the test specimens are mounted in a chamber that contains a saltwater mist, which is created by mixing water with salt in a ratio of 5% by weight. The chamber is maintained at a constant temperature and humidity, and the saltwater mist is sprayed continuously onto the specimens. After the specified test duration, the specimens are removed from the chamber and examined for signs of corrosion, such as rust or discoloration.

The results of the salt spray test are expressed in hours of exposure, and the longer the specimens resist corrosion, the better the corrosion resistance of the material or coating. The salt spray test is a valuable tool for evaluating the corrosion resistance of materials and coatings, but it is important to note that it is a laboratory test and may not necessarily reflect the actual performance of a material or coating in real-world environments.

Question 3

Fastener surface coating

Accepted Answer

Fasteners are used to join two or more objects together and they are often subjected to harsh environments, such as exposure to moisture, salt, and chemicals. To prevent corrosion and increase their durability, fasteners are often coated with various surface treatments. Here are some common types of surface coatings for fasteners:

Zinc coatings: Zinc is a common coating material for fasteners because it is inexpensive and provides good corrosion resistance. Zinc coatings can be either electroplated or hot-dipped. Electroplated coatings are thin and provide only limited corrosion resistance, while hot-dipped coatings are thicker and provide better protection.
Cadmium coatings: Cadmium is another coating material used for fasteners, especially in aerospace and military applications. Cadmium provides excellent corrosion resistance, but it is toxic and its use is being phased out due to environmental concerns.
Nickel coatings: Nickel is used for fasteners that require high corrosion resistance and also for decorative purposes. Nickel coatings can be electroplated or applied using electroless plating.
Chromium coatings: Chromium is used for fasteners that require very high corrosion resistance, such as those used in marine environments. Chromium coatings can be electroplated or applied using physical vapor deposition (PVD) or chemical vapor deposition (CVD).
Organic coatings: Organic coatings, such as paint or powder coating, can be applied to fasteners to provide a decorative finish and to protect against corrosion. Organic coatings are not as durable as metallic coatings, but they are often used for fasteners that are not exposed to harsh environments.

It's important to select the appropriate coating material and thickness based on the specific application and the expected operating conditions to ensure the fasteners will perform as expected. We normally use salt-spary test(SST) and kesternich test to inspection/request your need of surface coating.

Question 4

Everyone wants to find cheap. But what do cheap cost at your side?

Accepted Answer

You are doing great as a purchaser. However, are you looking for the cheapest product to save money? What if the cheapest price actually cost more? There are a lot of intangible cost that can be caused by a product. Are you dealing with a one-time-only business company?

Good news, SEC is a family-owned company in Taiwan starting from 1996. With almost 30 years of experience, we have been providing our customer with top quality products, responsible attitude, and sustainable management to avoid all the intangible cost.

Our cautious and rigorous SOP will not only provide you with high quality product but also a delightful purchasing process. Moreover, our products will allow your client to have a fabulous product experience and bring back more customers.

Question 5

What is type 17 screw?

Accepted Answer

Type 17 screws are a specific type of wood screw that are designed for use with softwood materials, such as pine or cedar. These screws are named after the Type 17 auger point, which is a specific type of sharp, pointed tip that allows the screw to easily penetrate and thread through the wood.

Type 17 screws have a unique design that includes a specially designed flute or groove just below the screw's head. This flute is designed to remove excess material as the screw is driven into the wood, which reduces the amount of splitting that can occur. This design feature makes them an ideal choice for attaching thin or soft wood without causing damage or splitting.

Type 17 screws are available in a variety of sizes and lengths, and they typically have a flat or countersunk head that can be easily driven flush with the surface of the wood. They can be used in a wide range of woodworking applications, including deck building, framing, and other outdoor construction projects where softwood is being used. They are also commonly used in cabinetry, furniture, and other indoor woodworking projects.

Question 6

What is Timber screw?

Accepted Answer

A timber screw is a type of screw designed for use with wood. Timber screws are often larger and longer than typical wood screws, and they are designed with a thicker shank to provide increased strength and stability.

Timber screws typically have a coarse thread that allows them to easily grip into the wood, providing a strong hold. They also often have a sharp, pointed tip that allows them to penetrate the wood without splitting or cracking it. The heads of timber screws may be flat, pan, or round, and they are typically designed to be driven with a drill or impact driver.

Timber screws can be used in a wide variety of applications where a strong and durable connection between pieces of wood is required. They are commonly used in framing, deck construction, and other outdoor building projects, as they are resistant to rust and corrosion. They can also be used in furniture construction, cabinetry, and other indoor woodworking projects, where their strength and durability make them a good choice for attaching heavy pieces of wood together.

Question 7

What is Drywall screw?

Accepted Answer

A drywall screw is a type of screw that is commonly used to attach sheets of drywall to wood or metal framing. Drywall screws have a sharp, pointed tip that allows them to easily penetrate through the drywall and into the framing material. They are also designed with a thread that is specifically intended to hold the drywall in place without tearing or cracking the gypsum material.

Drywall screws are typically made of steel and are available in various lengths and thicknesses, depending on the thickness of the drywall and the depth of the framing material. They often have a coarse thread to ensure a tight grip, and they may have a Phillips, square, or star-shaped head to allow for easy installation with a power drill or screwdriver.

In addition to their use in drywall installation, drywall screws can also be used in a variety of other applications, such as attaching wood or metal to drywall, or even fastening together

Question 8

Flange head and washer head

Accepted Answer

The main difference between SDS screws with flange head and those with washer head is the shape of the head of the screw.

SDS screws with flange heads have a wider head with a built-in washer that provides a larger bearing surface and distributes the load over a wider area. This can be useful for applications where a strong and secure hold is required, such as in construction or structural applications. The flange head can also help to prevent the screw from sinking too deeply into the material being attached, which can help to avoid damage to the material or the screw.

SDS screws with washer heads, on the other hand, have a flat or slightly rounded head with a separate washer that is attached underneath the head. The washer provides additional support and helps to prevent the screw from sinking too deeply into the material being attached. This type of screw is commonly used in applications where a neat appearance is desired, such as in woodworking or cabinetry.

Normally, Flange head SDS will goes with EPDM/PVC washer and washer head SDS will goes with EPDM steel bonded washer to avoid water leaking on the roof.

Both flange head and washer head SDS screws are designed to drill their own hole and create threads as they are driven into the material. This makes them a convenient option for attaching materials without the need for pre-drilling, and can save time and effort in many applications. When choosing between these two types of SDS screws, it is important to consider the specific needs of the application and select the screw that is best suited to the materials, load requirements, and aesthetic preferences.

Flange Head
Washer Head

Question 9

What kind of material of self-drilling screw should I use?

Accepted Answer

The material of the self-drilling screw you should use depends on the type of material you are attaching the screw to. Here are some general guidelines:

Wood: If you are attaching the screw to wood, you can use a self-drilling screw made of steel or stainless steel. Steel screws are strong and affordable, while stainless steel screws are more resistant to corrosion and rust.
Metal: If you are attaching the screw to metal, you should use a self-drilling screw made of stainless steel, as it is more resistant to corrosion and rust than regular steel screws.
Concrete or masonry: If you are attaching the screw to concrete or masonry, you should use a self-drilling screw made of carbon steel or a screw with a hardened steel tip. These screws are designed to drill into hard materials and create a secure hold.
Plastic: If you are attaching the screw to plastic, you should use a self-drilling screw made of a softer material, such as brass or nylon. These materials are less likely to crack or damage the plastic.

In addition to the material of the screw, you should also consider the coating or plating on the screw. Some common coatings include zinc, which provides basic corrosion protection, and black oxide, which provides improved corrosion resistance and a sleek appearance. Stainless steel screws do not require a coating, as they are already resistant to corrosion.

Overall, it is important to choose a self-drilling screw that is appropriate for the material you are attaching it to and that has the necessary strength and corrosion resistance for the intended application.

Question 10

What are the different between DIN and IFI standard self-drilling screw?

Accepted Answer

One key difference between DIN and IFI self-drilling screws is the measurement system used to define their size. DIN screws are typically measured in metric units, while IFI screws are measured in inches. Additionally, there may be differences in the specific design and performance characteristics of DIN and IFI self-drilling screws due to the different standards and testing procedures used to evaluate their performance.

Ultimately, the choice between DIN and IFI self-drilling screws may depend on the specific application, local regulations, and availability of each type of screw. It is important to carefully review the specifications of each screw and ensure that it is appropriate for the intended use.

Question 11

Why can't my self-drilling screw work?

Accepted Answer

There could be several reasons why a self-drilling screw is not working:

Wrong screw size: It is important to choose the right size of screw for the job, as using a screw that is too small or too large may not be able to effectively drill a hole and create threads in the material.
Worn or damaged drill point: Over time, the drill point of a self-drilling screw can become dull, damaged or broken. If this happens, the screw will not be able to drill a hole and create threads in the material.
Insufficient power or torque: Self-drilling screws require a certain amount of power and torque to drill through hard materials, so if the drill or driver used to install the screw is not powerful enough, the screw may not be able to work effectively.
Hard material: Self-drilling screws are designed to drill into hard materials, but if the material is too hard or thick, the screw may not be able to create a hole or drill through the material.
Incorrect installation technique: It is important to use the correct technique when installing self-drilling screws, such as holding the screw straight and applying even pressure. If the screw is installed at an angle or with too much force, it may not work effectively.

If you are having trouble with a self-drilling screw, it may be helpful to double-check with your supplier for the origin of production. Find the high quality product that can actual save cost. SEC is ready to serve you.

Question 12

What is the critical part of Self-drilling screw?

Accepted Answer

The critical part of an SDS (Self-Drilling Screw) is its drill point. The drill point is the specially designed tip of the screw that allows it to drill its own hole into the material being fastened, without the need for pre-drilling. The design of the drill point varies depending on the specific application and material being fastened, but generally consists of a fluted shape that helps to remove material as the screw is driven in. SEC have a patent drilling tip that have higher stability, thicker penetrating capability, faster drilling speed.

The shape and size of the drill point can affect the performance of the SDS, as well as its ability to drill through different materials. For example, a larger drill point may be needed for thicker or harder materials, while a finer point may be better suited for softer or more brittle materials. The shape of the flutes can also affect the amount of material that is removed and the speed at which the screw can be driven in.

Other critical parts of an SDS include the shank, which is the main body of the screw that contains the threads, and the head, which is the top of the screw that provides a surface for driving and tightening the screw. The shape and size of the shank and head can also affect the performance of the SDS, as well as its ability to distribute load and resist pullout or other forms of failure.

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