4 Quality Criteria For Custom-Made Screws

What materials can you use to make custom-made screws? What should you consider when selecting custom-made screws for your requirements? These are some of the questions that you may encounter when trying to select the most suitable custom-made screws.

This article will present to you the 4 most important things to consider within quality criteria when selecting the ideal custom-made screws.
 

1.To Confirm Corrosion resistance of materials

Different Materials Present Different Corrosion

 

• Stainless Steel

Stainless steel usually refers to the ability to resist the corrosion of air, water, or other media steel.

The characteristics of stainless steel screws are better. Because it has a strong corrosion ability. But it will rust in harsh conditions. For example, if stainless steel screws are in the case very wet, every day in the sun, wind, and rain. It's bound to rust over time.

Stainless steel is mainly used for: medical equipment, communication equipment, power facilities, outdoor occasions, outdoor decoration, etc.

• Aluminium

Aluminum is the world's second only metal in terms of output and consumption.

Because of the dense oxide protective film on the surface of aluminum, so aluminum is not easy to be corroded. It is often used to make chemical reactors, medical equipment, refrigeration equipment, petroleum refining equipment, oil, and natural gas pipelines, etc.

If you belong to these industries, you can choose aluminum as the raw material to produce your custom-made screws.
 

What Damage Will Be cause By Corrosion?

Metal corrosion will cause huge equipment maintenance costs and serious economic losses, such as increased design, manufacturing, maintenance, and repair costs or even harm and disaster due to corrosion.

The use of screws is the most extensive, the number of demand is also the largest. The corrosion resistance of screws determines the durability of their use. And it also has a significant impact on the safety of the equipment. Right materials can improve the performance of the screws.
 

Choose The Right Materials For your Industries

The small volume of the screws in the product is easy to be ignored. In addition to specifications, we should also consider the appearance of color and corrosion resistance.

In our previous article, How to Select The Best Custom Screws we also mention that the materials are of great importance in making custom screws.

2.To Check Appearance of Custom Made Screws

 

The Appearance Criteria for Custom Screws

What does check appearance mean? It means checking the surface treatment, wrinkles, and markings of custom screws.

Good quality screws have a smooth appearance and uniform color. There are no floating rust and oil stains. The teeth lines are neat, and the teeth are evenly spaced. The head has no cracks, and a balanced finish. There should be no burrs in the hole screws, dark spots on the surface, etc. show that the screw quantity is not good.
 

What is A Good Appearance of Screws?

Hexagon head bolts and screws (thread diameter 25mm) should be marked with convex or concave signs on the top surface of the head, or with concave signs on the side of the head.

The carbon steel product strength grade marking code must be composed of two numbers separated by ".". The meaning of the number before the "." in the marking code indicates the nominal tensile strength. The meaning of "." in the marking code and the number after the dot indicate the yield ratio.

The strength grade mark of stainless steel products is comprised of two parts. And they are separated by "--". The symbol before "--" in the logo code shows the material. Such as A2, A4, and other signs. The parts after "--" indicate intensity, such as A2-70.

Besides, the heads of hexagon socket screws are divided into knurled and non-knurled ones. Under normal circumstances, knurling is high-strength, such as class 12.9 hexagon socket screws.

If it is a combination-type custom screw, you should also check whether the screw leaks through the flat washer or spring washer.

3.To Measure the Mechanical Properties finished product of custom screws

 

Using Durometers Tests Hardness

First, we can use durometers to test the hardness of custom screws. Screw hardness standards can use the following hardness as parameters.
 

• Vickers hardness
• Brinell hardness
• Rockwell hardness
• surface hardness

It can be measured with
 

• Leeb hardness tester
• Brinell hardness tester
• Rockwell hardness tester
• Vickers hardness tester.

Generally speaking, low-strength screws such as grades 4.8 and 6.8 are tested by Brinell hardness, and those of grade 8.8 is tested by Rockwell hardness. Generally, the hardness of grade 12.9 reaches HRC39-44.
 

Anti-Corrosion Test: Professional Salt Spray Test

Second, it is to conduct a professional salt spray test. Salt spray test is a test that under the salt spray environmental conditions artificially simulated, created by salt spray test equipment. It is uesd to assess the corrosion resistance of products or metal materials.

Salt spray test requires a salt spray tester. The corresponding salt spray time of screws with different grades and different plating types is also different. The salt spray test time of screws is generally 24-72 hours.

Custom Made Screws Have different standards

Fasteners are divided into standard parts and non-standard parts, and standard parts have corresponding specifications and dimensions. The national standard and the German standard are more commonly used in the market.
 

Measure According to The Corresponding Standard

Under different standards, each grade of the screw has a different specification. You can use a vernier caliper to measure its length and diameter according to the corresponding standard.

The measurement results of high-quality screws should be consistent with the corresponding standard parameters. If it is a non-standard port, you need to check whether the measurement result matches the required standard parameters, and if it does not match, it needs to be reworked.
 

Procure High-Quality Custom Made Screws From Kai-x

These 4 ways to check whether you are purchasing the best custom-made screws are important. When you are importing, you can check their quality according to these four quality criteria.

What's more, the most effective way to choose the best screws is to cooperate with Kai-x. Kai-x creates high-quality custom-made screws and precision screws that meet the requirements of our customers.

If you want to start your orders, you can visit our website www.kai-x.com and search for our product catalog.