Magnetic Tube Magnet Bar

Magnetic Tube Magnet Bar

Magnets Bar Information

What is the magnetic bar？

The magnetic bars are named because they are made of strong neodymium magnets or SmCo magnets. The ferrite magnet is in the stainless-steel tube by complete or incomplete welding. Due to the appearance of stainless-steel rods or polished rods, many customers also call them magnetic rods, magnetic rods, magnetic filter rods, or magnetic rods.

They are the most effective permanent magnet devices for capturing and removing ferrous metals from various materials in different fields. According to different conditions, they can be assembled with other stainless-steel parts into a grate magnet, magnetic drawer, or magnetic trap. There are square and round solenoid tubes.

Magnetic Bar Specification

The magnetic rod is made of high-quality stainless-steel tube and rare earth alloy NdFeB and is made by a special production method. It can be combined on a holder to form a magnetic filter. When the iron-containing substance passes, it is attracted by the force bar, and the iron-containing substance is firmly adsorbed on the pipe wall of the magnetic bar to ensure the integrity of the equipment and the safety of the product.

Magnetic   strength	Working   Temperature(°C)
Steel tube outside diameter	2500GS	5000GS	6000GS	7000GS	8000GS	10000GS	12000GS	13000GS
Ф6(0.24")	350°C	-	-	-	-	-	-	-
Ф8(0.31")	350°C	-	-	-	-	-	-	-
Ф9(0.35")	350°C	-	-	-	-	-	-	-
Ф10(0.39")	350°C	-	-	-	-	-	-	-
Ф 12(0.47")	350°C	350°C	-	-	-	-	-	-
Ф16(0.63")	350°C	350°C	350°C	-	-	-	-	-
Ф19 (0.75")	350°C	350°C	350°C	180°C	-	-	-	-
Ф20.3(0.80")	350°C	350°C	350°C	180°C	-	-	-	-
Ф22 (0.85")	350°C	350°C	350°C	180°C	180°C	-	-	-
Ф25 (1.00")	350°C	350°C	350°C	180°C	180°C	180°C	180°C	180°C
Ф32 (1.25")	350°C	350°C	350°C	180°C	180°C	180°C	180°C	180°C
Ф38 (1.50")	350°C	350°C	350°C	180°C	180°C	180°C	180°C	180°C
Ф50 (1.75")	350°C	350°C	350°C	180°C	180°C	180°C	180°C	180°C
Ф63(2.48")	350°C	350°C	350°C	180°C	180°C	180°C	180°C	180°C

Easy clean Magnetic bar

Easy Clean Shell

The cleaning shell specially used for magnetic strips, by inserting and pulling out the strip magnets from the box, the magnetic material attached to the bar can be removed.

The easy-to-clean magnetic bar independently developed by great magetch is widely used in the food, plastic, and pharmaceutical industries. With a screw head plug, it can prevent the magnetic rod from sliding out and keep the inside of the magnetic rod clean. Different screw plugs can be used to take out the magnetic rod after use so that impurities can be removed.

Magnetic Bar Purchase FAQ

What should I do before I purchasing a magnetic bar？

1. Confirm the shape and size of the magnetic bar: 

Our standard stainless steel pipe is 25 mm. (1 inch) in diameter, the length required by each customer does not exceed 2500 mm.

2. Confirm the gauss of magnetic bar: 2500 Gs or 8000 Gs or 10000Gs or 12000Gs or 13000Gs 14000GS;

3. Confirm the maximum working temperature: 

There are 6 series for customers to choose

●N series temperature up to 80 degrees Celsius

●M series up to 100 degrees Celsius

●H series temperature up to 120 degrees Celsius

●The SH series can reach up to 150 degrees Celsius

●UH series up to 180 degrees Celsius

EH series up to 200 degrees Celsius 

4. Confirm whether the material is corroded;

5. Confirm that the magnetic tube cover: 316L or 304 stainless steel.

6. Confirm the threaded hole of the solenoid:

1) There are threaded holes on both ends, easy to install.

2) Tap a threaded hole on one end, and perform flat welding on the other end.

3)both ends are flat welded. 

7. Confirm the quantity of electromagnetic tube: the price of different quantities is different; the price of more quantity is lower.

How does the magnetic filter tube work?

The magnetic filter rod/filter rod/tube is made of 304 or 316 stainless steel tube, pole plate, end plug, and permanent magnet. The higher the surface Gaussian of the tube, the higher the price. Since permanent magnets are the most expensive parts, we will tell you how unethical companies can reduce the cost of manufacturing electromagnetic tubes with high surface Gauss.

1. Reduce the volume of the magnet

Disadvantages: The surface of the pipe is uneven and easy to break.

Reduce the magnet diameter as shown in the figure below:

What should I know when buying magnetic filter rods/rods/tubes?

The magnetic flux density of the magnetic filter rod/rod/tube composed of extremely small magnets will not decrease by increasing the diameter of the pole plate, which is due to the magnetic flux density test performed around the circumference of the pole plate. 

However, due to the lack of support of the magnet in the tube, the tube wall will collapse in time. 

In addition, since the stress cannot be evenly distributed and concentrated only on the plate, the tube is easily broken around the plate, making the entire tube unusable and contaminating the material in more serious cases.

2. Use shredded magnets 

Disadvantages: The surface Gaussian is not uniform, which is easy to cause an efficiency drop.

Broken and broken magnets are defective.

However, some unethical companies will seal them in tubes anyway, because these defects are indistinguishable from appearance and are also difficult to detect.

3. Use a "secondary magnet"

Disadvantages: The magnetic field of the tube is not uniform and the consistency is poor.

The so-called "secondary magnets" are magnets produced by top manufacturers for top buyers. However, due to various factors, these products are discarded waste products. Since they are still high-performance products, some unethical companies will buy them at discounted prices. 

However, these "secondary magnets" are mostly thin pieces 3 to 10 mm thick. When observed with a magnetic pole observer, these defects will appear on their own, as shown in the following figure:

What should I know when buying magnetic filter rods/rods/tubes? 

In addition, the sources of these "secondary magnets" are inconsistent. Therefore, the performance of the next batch purchased cannot be guaranteed, resulting in poor consistency between batches. 

4. Reduce the thickness of the stainless steel pipe 

Disadvantage: The service life of the solenoid tube is shortened.

SS304 and SS316 stainless steel are commonly used materials for manufacturing magnetic filter rods/rods/tubes. In the market, the thinnest SS304 tube is between 0.45-0.50 mm. If the tube becomes thinner, the life of the tube will be greatly reduced. 

Due to fewer applications and incomplete specifications, the thinnest SS316 tube is found to be between 0.75-0.80mm. This is also the reason why the surface Gaussian of the magnetic filter rod/bar/tube made of SS316 is lower than that of the tube made of SS304.

If the mass production needs to be stable, the company can produce a 0.5mm thick SS316 pipe (the minimum order quantity is 500kg). However, some unscrupulous companies will manufacture solenoid tubes with a thickness of only 0.3mm, allowing the use of weaker magnets to achieve higher surface, Gauss. 

How the above method unethically reduces the cost of magnetic separation. Please be careful when purchasing magnetic filter rod/rod/tube products.

What are the characteristics of the magnet?

Before the magnets bar test, let’s first understand these terms:

1) Magnetic flux: Set in a uniform magnetic field with a magnetic flux density of B, there is a plane with an area S and perpendicular to the direction of the magnetic field. The product of the magnetic flux density B and the area S is called the magnetic flux passing through this plane. Referred to as Magnetic Flux. Scalar, symbol "Φ". Simply put: "Use the magnetic field density to measure the strength of the magnetic field"

2) Gauss: is the unit of measurement of magnetic flux, which refers to the number of magnetic lines of force passing through each square centimeter. A Gauss meter is usually used to measure the strength of the magnetic rod. 

3) Tesla: It is the derived unit of the international system of magnetic flux density or magnetic induction, usually expressed by T. At the International Metrology Conference held in Paris in 1960, this unit was named in memory of Nikola Tesla, an American Serbian inventor, mechanical engineer, and electrical engineer who made important contributions to the field of electromagnetics.

 The familiar Tesla cars are named after this Tesla background. The conversion formula of Tesla and Gauss is: 1 Tesla = 10000 Gauss

4)Magnetic Gradient: The rate of change of magnetic field strength or the rate of change of magnetic field density within a unit distance (for example, 1 cm). The degree of inhomogeneity of the magnetic field can be measured by the magnetic field gradient. As shown in the figure below, the distribution of magnetic field lines in a uniform magnetic field is uniform, but the distribution of magnetic field lines in an uneven magnetic field is not uniform. The larger the magnetic gradient, the easier it is to adsorb.

5) Pull Force：The adsorption force of a ferromagnetic object in a magnetic field is usually expressed in kg or Newton as the unit of magnetic force. Usually use a tensile tester to test.

6) Magnet coercive force：Also known as coercivity or coercivity, it is one of the characteristics of magnetic materials and refers to the magnetic field strength required to reduce the magnetization to zero after the magnetic material has been magnetized to magnetic saturation. Coercivity represents the ability of a magnetic material to resist demagnetization. It will be represented by the symbol of HC, and the unit is A/m (international standard system) or Oe (gauss unit system).

The coercivity can be measured with a magnetometer or B-H analyzer (such as FE-2100H permanent magnet material measuring device). If the coercivity is large, it is called hard magnetism and can be used as a permanent magnet material. Permanent magnets can be used in motors, magnetic storage media (such as hard drives, diskettes or tapes), and strong magnetic rods. Ferromagnetic materials with low coercivity are called soft magnetism and can be used in the iron cores of transformers and inductors, and read/write heads of magnetic storage media.

Why choose us?

For the long-term use of a magnetic bar, at Greatmagtech, we use the best raw materials to make products. This makes the customer repurchase rate as high as 80%.

Magnetic rod adsorption iron powder

Seven system guarantees

1. Quality-use one-handed magnet

At Greatmagtech, all we use are brand new magnets. 

Brand new magnetic bar material

2. Supply chain system

Supply Chain System

Raw material quality standards

Our purchasing manager has more than 15 years of purchasing experience, and is experienced in quality control, and has the advantages of different factories, different products, and different quality levels.

To ensure the quality of our products

Has been in a leading position in the industry

We focus on materials and review supplier qualifications

Per year. If both audits fail, the supplier will be eliminated. 

In addition, the supplier’s raw material quality.

Unqualified items occur more than once a year.

We will choose to terminate cooperation with suppliers.

Choosing better suppliers can guarantee the quality of our products.

This is our first step in serving our customers. But we do more than you think. 

Efficient ERP system

Production development

Purchasing Department

Super-efficient warehouse

Collaboration and communication.

The most accurate method

satisfy the needs of clients

Efficient teamwork system to ensure that you can arrange the order to be produced first

3. Inventory system

We have a large inventory of magnetic bars, delivery time

Regular size 1~3 days

Custom 7-14 days

Our company has a large amount of regular inventory.

If you are a regular specification,

We can ship the goods on the day of payment.

If it’s a custom size.

We have a lot of assembly materials.

Can be assembled within 14 days after delivery 

4. Quality inspection system

Different from the magnetic bar on the market, the stainless steel used in our products is food-grade stainless steel, which means more environmental protection and durability. It can be used in direct contact with food and is harmless, and the quality has been certified.

The lead content of food-grade stainless steel is much lower than that of general stainless steel. Our products have passed China International CNAS CTT testing agency accredited testing, You can use it without safety concern.

Before shipment, 10% of our magnets bar will be randomly inspected. Test Gauss performance and surface flatness, and surface flaws. And issue a product test report to send to the customer.

5. Packaging

GME has more than 15 years of experience in magnet packaging. We will learn how to reduce transportation costs while ensuring that the product is not damaged.

We can choose different packaging methods according to different magnetic bar characteristics and transportation methods. We add foam, waterproof bags and wooden blocks to the packaging.

In the past five years, the complaint rate for packaging damage was less than 0.04%.

Everything we do is for customers

Receive our products.

6. After-sales service system: after-sales service

Our reply will always be available within 12 hours.

Product and packaging pictures before shipment.

Provide invoices, packing lists, and documents in a timely manner.

Promptly issue shipping notice and cargo arrival notice.

Application suggestions and techniques for magnetic chuck.

7. About the complaint system

Call customers within 12 hours.

Communicate with customers to understand what happened, the quantity, and the order or batch.

Ask customers to take pictures

Internal inspection to find out the cause of the problem.

Provide a suitable and satisfactory solution, replenishment, or refund.

Apologies and avoid problems with future orders.

Demagnetization rate of magnetic bar

The price of magnetic bars on the market is very different. The magnetic bars with different prices are mainly due to the different demagnetization rates of the magnetic bars. Good magnetic bars have better permanent magnetism, while poor ones have very fast demagnetization. The main factors leading to the demagnetization of the magnetic rod are:

1) High temperature (exceeding the temperature resistance grade of the magnet material). Usually, it is lower than 80 degrees, and the influence on the magnet bar is limited. If it exceeds 80 degrees, you need to choose the corresponding high temperature resistant magnet.

2) The magnet material itself. The magnet itself contains too many impurities, the weaker the magnetic retention ability. Usually choose to choose a material with a high coercivity (such as Alnico, etc.) in order to preserve the magnetism as much as possible and not make it disappear.

3) Strong external magnetic field. Generally, if the external magnetic field is stronger than the magnetic rod itself, it will easily lead to the loss of magnetism.

4) Impact. Frequent high-frequency impacts will affect demagnetization. Therefore, avoid rough installation and disassembly, and avoid installation at the place of vibration source.

5) Humidity. It means that the magnet itself will affect the magnetic force in a humid environment. The outside of the magnetic bar is usually covered with stainless steel, so it will not be affected by washing with water.

Note: The demagnetization of the magnetic rod is not directly related to the number of times the magnetic substance is adsorbed. In the process of the magnetic rod used by many Chinese companies, the demagnetization will occur quickly (more than 30% demagnetization in a few months to a year). It is believed to be caused by too much foreign matter adsorption. In fact, there is no direct relationship between the two. The demagnetization is mainly caused by the material of the magnet itself and its processing process. The demagnetization rate of Greatmagtech's magnet is about 1% five years, and it is no problem to use a magnet for more than ten or twenty years.

Strength check frequency of the magnetic bar

The strength check of the magnetic bar is normally to use a Gauss meter to check the strength of the magnetic bar and keep the corresponding records. In the normal use environment of the magnetic bar, the weakening of the magnetism is relatively slow; there is no clear and specific requirement for the inspection frequency of the magnetic bar. The usual inspection frequency in the industry is 1 month to 3 months. If the environment used is harsh (such as high temperature, vibration, etc.), it is recommended to increase the frequency of inspection.

How to detect and identify stainless steel 201 304 316

The difference between 304 and 316 stainless steel

It is practically impossible to see the difference between 304 and 316 stainless steel with the naked eye. Many people are confused when they see these numbers. Let me look at the difference between stainless steel 304 and 316 today.

First, 316 stainless steel contains Mo, which has better corrosion resistance in high-temperature environments than 304 stainless steel. Therefore, in high-temperature environments, engineers generally choose 316 material parts.

Secondly, there are differences between the two in terms of grades; 304 stainless steel corresponds to Chinese grade 0Cr18Ni9; 316 stainless steel corresponds to Chinese grade 0Cr17Ni12Mo2.

Third, 316 mainly reduces the Cr content, increases the Ni content, and increases Mo 2%~3%. Therefore, its corrosion resistance is stronger than that of 304, and it is suitable for use in chemical, seawater, and other environments. Similarly, the cost of 316 is also higher than that of 304. Generally, 316 is used in places with higher requirements to replace 304.

It is practically impossible to see the difference between stainless steel 304 and 316 with the naked eye. There is a more intuitive way to distinguish, using stainless steel potion for identification. For the use of stainless-steel potion, please see the following.

How to test stainless steel with a detection agent

We can use professional stainless-steel testing reagents to easily detect the quality of magnetic bar stainless steel. If you need it, just tell us when you place the order. We can give you stainless steel reagents for free and give you detailed instructions for use 

Become our supplier now!

In order to better serve customers and let distributors develop their businesses, Greatmagtech has a plan to support distributors. If the purchase amount exceeds 30,000 US dollars from our company, we can give distributors, Gauss meters and magnetic pole detection sheets for free. And you can share the internal magnet learning materials to help you improve your magnet expertise.

Reference:

1)   "IFS Foreign Body Control Guide"

2)   "GB/T12796-2012 Permanent Ferrite Magnet Part 1 General Specification"

3)   "GB/T180-2012 Rare Earth Cobalt Permanent Magnet Materials"

4)   "GB∕T13560-2017 Sintered NdFeB Permanent Magnet Material"

5)   "GB/T14989-2015 iron cobalt vanadium permanent magnet alloy"

6)   "GB/T3217-2013 Permanent magnet (hard magnetic) material magnetic test method"