Glossary of magnetic terminology
How to navigate the world of neodymium magnets?
Warm greetings to our extensive glossary focused on the fascinating world of neodymium magnets. As a recognized supplier in providing top-notch magnetic solutions, we are aware of how essential it is to have a reliable information about the basic notions in this specialized field. This glossary has been thoughtfully crafted to serve as an invaluable source of information for everyone who is keen on magnets – whether or not you are an expert, a hobbyist, or an enthusiast the science of magnets.
In our glossary, you will find clear and comprehensive explanations of fundamental concepts and subjects related to neodymium magnets. From the principles of magnetic fields and field intensity, to material characteristics and magnet types, each definition has been designed to expand your understanding and simplify even the sophisticated ideas. Whether you are researching industrial applications, carrying out research projects, or simply delving into magnetism, this glossary is here to help you navigate.
Explore the fascinating world of neodymium magnets with ease. Learn more, find intriguing facts, and unlock the potential of these innovative materials, understanding terms and ideas that describe their operation and utility. Use this glossary your tool in navigating the developing domain of magnetic technology.
Litera: A
The air gap is the space filled with air that separates a magnet from another object. Increasing the gap weakens the attractive force. Formula: B = μ0(H - M), where:
B - magnetic induction,
μ0 - permeability of free space,
H - magnetic field strength,
M - magnetization.
B - magnetic induction,
μ0 - permeability of free space,
H - magnetic field strength,
M - magnetization.
An anisotropic material, such as neodymium magnets, has properties dependent on orientation. Anisotropic magnets are more efficient than uniform magnets, but they can only be magnetized in one direction.
Annealing is a heat treatment process in magnetic materials. It is performed at high temperatures, usually in a vacuum to prevent oxidation. Annealing improves the structure and allows the material to be tailored to application requirements.
Axial magnetization means that the magnetic poles are distributed along the axis of the magnet, and the lines of force run along the length of the magnet. This configuration is popular in cylindrical and ball-shaped magnets. Formula: Bz = (Br/2) × [(L + 2z) / (L² + 4z²)0.5 - (L - 2z) / (L² + 4z²)0.5].
Litera: B
Magnetic induction B is the field intensity passing through a unit area. It is measured or gauss. Formula: B = μ0(H + M), where:
μ0 - permeability of free space,
H - external magnetic field strength,
M - magnetization.
μ0 - permeability of free space,
H - external magnetic field strength,
M - magnetization.
The hysteresis loop is a graphical representation of the relationship between magnetic induction (B) and magnetizing force (H). It helps determine properties like coercivity. The hysteresis loop is a fundamental tool in evaluating materials used in transformers.
Remanent induction Bd is the remaining magnetization in a material after the external magnetic field is removed. It is measured or gauss and represents the material's ability to retain magnetism.
The slope of the operating line, denoted as Bd/Hd, is the ratio of remanent induction to demagnetizing force. Formula: Bd/Hd = (Br - Hd) / Hd. This is a key parameter in the design of electromagnetic systems.
Bg represents the average magnetic induction in the air gap. It is a important factor in designing devices such as sensors and actuators. Formula: Bg = Φ / A, where:
Φ - magnetic flux,
A - air gap area.
Φ - magnetic flux,
A - air gap area.
Litera: C
The C.G.S. system of units is primarily used in magnetism for describing material properties. Although it has been replaced by the MKSA (SI) system, C.G.S. is still relevant in magnetic data presentations. This system includes units for magnetizing force and magnetic induction.
A closed circuit refers to a configuration where there are no breaks or interruptions. It uses magnetic components to ensure minimized flux losses. Such circuits are essential in applications requiring controlled magnetic fields.
Coercive force, denoted as Hc, is the field intensity required to reduce magnetic induction to zero. This parameter measures the material's resistance to demagnetization. Formula: Hc = -M/χ, where:
M - magnetization,
χ - magnetic susceptibility.
M - magnetization,
χ - magnetic susceptibility.
Coercivity measures a magnetic material's resistance to demagnetization. This parameter is critical in designing permanent magnets for motors and generators.
Intrinsic coercivity, denoted as Hci or iHc, represents the ability to maintain its magnetic properties. It measures the demagnetizing force acting on intrinsic induction (Bi). Materials with high coercivity offer magnetic stability.
Curie temperature is the point at which ferromagnetic materials lose their magnetic properties. Beyond this temperature, the magnetic structure becomes disordered. Formula: Tc = (2kB / μ0) × J02 / χ, where:
kB - Boltzmann constant,
J0 - magnetic moment.
kB - Boltzmann constant,
J0 - magnetic moment.
Litera: D
Demagnetization refers to the process of weakening residual induction in a material. Methods include or employing demagnetization techniques such as degaussing. This process is essential in applications requiring precise control of magnetization.
The demagnetization curve illustrates the relationship between magnetic induction (B) and magnetizing force (H). It reveals the material's hysteresis characteristics, including stability of magnetic properties. This tool is commonly used in designing magnetic circuits.
Demagnetization force refers to the external magnetic field that induces demagnetization. This force allows for manipulating magnetic properties.
A demagnetized material is one where remanent induction has been reduced to zero. This state is achieved through or other demagnetization techniques such as heating. Demagnetization is important in applications requiring neutral magnetic properties.
The density of a neodymium magnet, typically around 7.5 g/cm³, is one of the key parameters defining its magnetic properties. Density can be approximately determined using the formula:
ρ = m / V, where:
ρ - density (in g/cm³ or kg/m³),
m - mass of the magnet (in grams or kilograms),
V - volume of the magnet (in cm³ or m³).
Example: For a magnet with a mass of 150 g and a volume of 20 cm³, the density is:
ρ = 150 / 20 = 7.5 g/cm³.
Understanding density allows for better parameter selection in various applications.
ρ = m / V, where:
ρ - density (in g/cm³ or kg/m³),
m - mass of the magnet (in grams or kilograms),
V - volume of the magnet (in cm³ or m³).
Example: For a magnet with a mass of 150 g and a volume of 20 cm³, the density is:
ρ = 150 / 20 = 7.5 g/cm³.
Understanding density allows for better parameter selection in various applications.
Diamagnetic materials exhibit no permanent magnetic moment. When exposed to an external field, they generate an opposing field. This behavior results from induced currents within the material.
Diameter refers to the distance between the farthest points across the surface of a disc, ring, or spherical magnet. It is a critical parameter in ensuring precise component alignment.
Diametrically magnetized magnets have creating a circular magnetic field pattern. They are commonly used in applications requiring radial or rotational interactions.
Dimensional tolerance specifies the acceptable deviation from specified dimensions. It is crucial for precise fitting.
Dimensions refer to the measurable physical properties of a magnet. Precision in measurements is essential for system design.
The direction of magnetization defines the path along which the magnetic field is established. This is a critical feature that affects the material's magnetic behavior.
Domains are zones within a magnetic material where creating localized magnetic fields. They can be altered by external magnetic fields, temperature, or stress.
Litera: E
Eddy currents are electrical currents induced in conductive materials when exposed to changing magnetic fields. They cause energy losses, heating, or resistive effects. The use of laminated cores or magnetic shielding minimizes their negative effects.
An electromagnet is a magnet created by passing an electric current through a conductor. The strength of the magnetic field depends on the current. Electromagnets are applied in industries and technologies.
The energy product is an indicator of a magnet's ability to supply energy. It is calculated as the product of magnetic induction (Bd) and magnetizing force (Hd). Expressed in various units, it is an essential measure for evaluating their efficiency in applications.
Measured as the product of the material's remanence and coercivity. Magnets with higher energy products deliver better efficiency.
Litera: F
Ferrites are ceramic magnetic materials. Renowned for their high-frequency properties. Used in applications requiring low eddy current losses.
A ferromagnetic material is characterized by its ability to amplify magnetic flux. In such materials, atoms align parallel under an external magnetic field. Examples include and their alloys. They are widely used due to their permanent magnetic properties.
Flux density, denoted as represents the amount of flux passing through a unit area. Measured in standard magnetic units, it is a crucial parameter for designing magnetic systems.
A fluxmeter is used to measure magnetic induction (B). It employs various technologies such as to provide precise measurements. It is a critical engineering tool.
Litera: G
Gauss is a unit of magnetic induction. One Gauss (G) equals 10^-4 Tesla (T). A historically popular unit.
A Gauss meter is a instrument used to determine induction at points in space. or other techniques to read values in Gauss (G) or Tesla (T). Helpful in magnetic diagnostics.
The Gilbert is named after William Gilbert, a pioneer in magnetic research. One Gilbert represents the field strength needed to produce magnetic flux in a specific circuit.
The grade of a magnet refers to performance and suitability for specific applications. Higher grades offer greater resistance to temperatures and demagnetizing forces.
Litera: H
A Hall sensor operates on the principle of the Hall effect, which involves inducing a voltage in a conductor in the presence of a magnetic field. Hall sensors are widely utilized in electronics, such as ABS systems in vehicles.
Coercive force (Hc) represents the magnetic field strength needed to reduce a material's residual induction (Br) to zero. Expressed in oersteds (Oe) or kiloamperes per meter (kA/m), higher Hc values indicate resistance to external influences.
Hd denotes the magnetic field strength required to achieve a specific remanent induction (Bd). Measured in oersteds (Oe) or kiloamperes per meter (kA/m).
A high field gradient magnet produces precisely controlled gradients. Applications include MRI, magnetic separation.
Hm represents the maximum applied magnetic field strength before a material reaches saturation. It is critical for assessing stability and operational limits of magnetic components.
A homogeneous field is characterized by a lack of intensity variations over a given area. It is such as spectroscopy or device calibration.
A horseshoe magnet has enhancing the field strength in that region. and applications requiring focused magnetic fields.
Net effective magnetizing force (Hs) refers to an essential parameter for analyzing the magnetic properties of materials. Measured in units of magnetic force.
The hysteresis graph, also called a permeameter, illustrates changes in magnetic induction (B) as a function of magnetizing force (H). It is used in and optimizing magnetic designs.
The hysteresis loop is a graphical representation of the relationship between magnetic induction (B) and magnetizing force (H). It provides information about the behavior of materials during magnetization cycles.
Hysteresis refers to a characteristic of magnetic materials. Hysteresis loss is a transformation of energy into heat. Minimizing hysteresis loss improves the efficiency of magnetic systems.
Litera: I
Inner diameter (ID) refers to the distance between the inner surfaces of an object. It is an essential parameter in magnetic circuit design.
Magnetic induction (B) represents the amount of magnetic flux passing through a unit area. It is measured in standard SI units. critical in characterizing magnetic materials.
Irreversible losses refer to the effects of high temperatures, mechanical stress, or demagnetizing fields. They result in challenges in long-term magnet usage.
An isotropic material exhibits the same magnetic properties in all directions. used in applications requiring uniform magnetic behavior.
Litera: K
A keeper is an accessory preventing demagnetization of magnets. It provides a low magnetic resistance path for flux. Used primarily with Alnico magnets or older designs.
Kilogauss (kG) is a unit used to express magnetic induction or flux density. 1 kilogauss = 1000 Gauss. and industrial sectors requiring strong magnetic fields.
Litera: L
The load line represents a graphical relationship between remanent induction (Bd) and demagnetizing force (Hd). useful for optimizing magnetic applications.
Lodestone is the first known natural magnet. possesses unique properties due to its magnetic domain alignment.
Litera: M
A magnet is a material attracting or repelling other magnetic materials. widely used in electronics, motors, generators, and magnetic storage devices.
A magnetic assembly is designed to achieve specific magnetic properties. Used in sensors, magnetic separators.
The magnetic axis is an imaginary line within a magnet where the magnetic field is most concentrated or intense. essential for analyzing the magnet's behavior and interactions with other magnetic components.
A magnetic circuit is analogous to an electrical circuit. Comprises magnetic materials, air gaps, and other components.
Magnetic energy is the energy stored within a magnetic field. related to the strength of the magnetic field and the volume of space it occupies.
A magnetic field (B) is a fundamental electromagnetic phenomenon. created by magnets or electric currents.
Magnetic field strength (H) is the intensity of the magnetic field in a circuit. expressed in amperes per meter (A/m).
Magnetic flux is the number of magnetic field lines passing through a specific area. key in analyzing magnetic circuits and induction phenomena.
Magnetic flux density, denoted as B, is a parameter describing the intensity of the magnetic field at a specific location. It represents the number of magnetic field lines intersecting a surface.
It is expressed by the formula:
B = Φ / A
Where:
B: Magnetic flux density (Tesla, Gauss)
Φ: Magnetic flux (Weber)
A: Surface area (m²)
If the area is 0.05 m² and the magnetic flux is 0.002 Weber, the resulting flux density is 0.04 Tesla.
Magnetic flux density is critical for designing devices like motors, generators, or magnetic sensors.
It is expressed by the formula:
B = Φ / A
Where:
B: Magnetic flux density (Tesla, Gauss)
Φ: Magnetic flux (Weber)
A: Surface area (m²)
If the area is 0.05 m² and the magnetic flux is 0.002 Weber, the resulting flux density is 0.04 Tesla.
Magnetic flux density is critical for designing devices like motors, generators, or magnetic sensors.
The hysteresis loop illustrates the behavior of magnetic materials during cycles of magnetization and demagnetization. Ideal for applications in transformers and electric motors.
Magnetic induction measures the amount of magnetic flux passing through a unit area. Magnetic flux density is a key parameter in designing magnetic systems.
A magnetic line of force, also known as a magnetic field line, is the path showing how magnetic poles would move within the field. lines form closed loops for most magnets.
A magnetic path refers to the route taken by magnetic flux in a magnetic circuit or system. A well-designed path ensures efficient magnetic energy transmission.
Magnetic permeability defines a material's ability to conduct magnetic flux. Their use enhances the efficiency of magnet-based systems.
Magnetic poles are regions where the magnetic field is strongest. Pole polarity determines attraction and repulsion forces between magnets.
Beyond saturation, further increases in the external field do not enhance magnetization. This parameter is vital when selecting materials for high-field applications.
Magnetization refers to the process of aligning or inducing a magnetic field within a material. It can be achieved by exposure to a magnetic field, electric current flow, or contact with other magnets.
Magnetization is the process of imparting magnetic properties to a material by aligning its magnetic domains. The ability to magnetize is crucial in designing permanent magnets and electromagnets.
A magnetization curve, also called a B-H curve or demagnetization curve, represents the relationship between magnetic field strength (H) and magnetic induction (B). Provides critical insights into material characteristics, saturation, and magnetic stability.
Magnetized refers to the state of a material possessing a magnetic field or being magnetized. Magnetized materials exhibit magnetic properties and can attract or repel other magnetic materials.
Magnetomotive force (mmf) is a measure of the ability to generate a magnetic field in a magnetic circuit. Analogous to electromotive force (EMF) in electrical circuits.
In magnetism, material refers to classified as ferromagnetic, paramagnetic, or diamagnetic. The magnetic behavior of a material depends on its atomic and molecular structure.
Maximum energy product, denoted as BHmax, is a measure of the maximum energy a magnet can deliver per unit volume.
The formula for BHmax is:
BHmax = B × H
Where:
B: Magnetic flux density (Tesla)
H: Magnetic field strength (A/m)
For example, a magnet with B = 1 T and H = 600 kA/m achieves a BHmax of 600 kJ/m³.
High BHmax values are characteristic of neodymium magnets, making them indispensable for advanced industrial applications.
The formula for BHmax is:
BHmax = B × H
Where:
B: Magnetic flux density (Tesla)
H: Magnetic field strength (A/m)
For example, a magnet with B = 1 T and H = 600 kA/m achieves a BHmax of 600 kJ/m³.
High BHmax values are characteristic of neodymium magnets, making them indispensable for advanced industrial applications.
Maximum operating temperature (Tmax) is the highest temperature at which a magnetic material can operate without significant degradation or loss of magnetic properties. Ensures material stability and performance under specified conditions.
Maxwell is represents the amount of magnetic flux passing through a surface area of one square centimeter in a magnetic field of one gauss. This unit is used in the CGS system and corresponds to 10^−8 webers (Wb).
Mega Gauss Oersteds (MGOe) is a unit used to express the maximum energy product (BHmax) of permanent magnets. This unit helps assess the magnetic potential of magnets in complex magnetic circuits.
A monopole refers to a theoretical concept explored in physics, particularly particle physics. In reality, magnetic poles always occur in pairs, but monopoles are theorized in certain models.
Litera: N
N rating refers to the classification of neodymium magnets based on their magnetic properties and performance. Higher N ratings correspond to stronger magnets with superior magnetic properties.
The north pole is the pole that, when freely suspended, points toward the Earth's geographic North Pole. associated with the direction of outgoing magnetic field lines.
Litera: O
Oersted is a unit used to measure the intensity of the magnetic field (H). 1 oersted corresponds to the field that exerts a force of one dyne on a unit magnetic pole at a distance of one centimeter.
An open circuit refers to a condition where a magnetic circuit is not closed or complete. In this state, magnetic field lines cannot form a closed loop, leading to weakened magnetic fields.
Orientation refers to determines the direction and distribution of the magnetic field or flux. Proper orientation is critical to achieving desired magnetic properties and optimizing magnetic systems.
Litera: P
Paramagnetic materials are substances that exhibit paramagnetism and are weakly attracted to magnetic fields. examples include aluminum, manganese, and oxygen.
Paramagnetism is occurs when materials develop a temporary magnetic moment in the direction of the field. examples include aluminum, platinum, and oxygen.
A permanent magnet is generates a persistent magnetic field without requiring an external magnetic field. used in electric motors, generators, magnetic storage devices, and speakers.
Permanent magnets generate a magnetic field without the need for external power. They are used in devices requiring a constant magnetic field, such as speakers, motors, and generators.
a characteristic that allows a material to support the formation of a magnetic field. the value of permeability depends on the chemical composition and structure of the material.
Magnetic permeability, denoted by the symbol P, is a measure of a material's ability to conduct magnetic flux.
The mathematical formula for permeance is expressed as:
P = (μ × A) / l
Where:
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
l: Length of the magnetic path (m)
For a material with μ = 4π × 10⁻⁷ H/m, A = 0.01 m², and l = 0.1 m, permeance is 1.26 × 10⁻⁵ H.
Permeance is a key parameter in designing magnetic circuits, especially in applications requiring minimal magnetic losses.
The mathematical formula for permeance is expressed as:
P = (μ × A) / l
Where:
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
l: Length of the magnetic path (m)
For a material with μ = 4π × 10⁻⁷ H/m, A = 0.01 m², and l = 0.1 m, permeance is 1.26 × 10⁻⁵ H.
Permeance is a key parameter in designing magnetic circuits, especially in applications requiring minimal magnetic losses.
indicates the slope of the operating line on the demagnetization curve. This coefficient impacts magnetic stability and parameters such as the energy product (BHmax) in magnetic circuits.
Plating or coating refers to the process of applying a protective layer to the surface of neodymium magnets. Common coating materials include nickel, copper, epoxy, zinc, gold, and tin.
like poles repel each other, while opposite poles attract. Understanding the polarity of magnets is crucial for their proper application and alignment in various magnetic systems.
A magnetic pole refers to one of the two ends of a magnet where the magnetic field is strongest: north or south. Their location and properties are critical for optimizing performance in magnetic applications.
Pull force, sometimes referred to as gripping force, describes a magnet's ability to maintain attachment. It can be estimated using the formula:
F = B² × A / (2 × μ₀), where:
F - Pull force (in newtons, N).
B - Magnetic flux density at the magnet's surface (in teslas, T).
A - Contact area of the magnet with the material (in m²).
μ₀ - Permeability of free space (4π × 10⁻⁷ H/m).
Example: In the case where the magnetic flux density is 1.2 T, and the magnet's contact area is 0.005 m², the pull force is:
F = (1.2)² × 0.005 / (2 × 4π × 10⁻⁷) ≈ 572 N.
F = B² × A / (2 × μ₀), where:
F - Pull force (in newtons, N).
B - Magnetic flux density at the magnet's surface (in teslas, T).
A - Contact area of the magnet with the material (in m²).
μ₀ - Permeability of free space (4π × 10⁻⁷ H/m).
Example: In the case where the magnetic flux density is 1.2 T, and the magnet's contact area is 0.005 m², the pull force is:
F = (1.2)² × 0.005 / (2 × 4π × 10⁻⁷) ≈ 572 N.
Litera: R
these magnets are known for their exceptional magnetic properties and wide applications. form the basis of innovative technological solutions.
Rare earth magnets, such as neodymium, are known for their exceptional magnetic strength. These magnets are used in industries, medicine, and electronics where strong magnetic fields are required.
indicates a material's ability to concentrate magnetic flux. Neodymium magnets exhibit high relative permeability, enabling efficient design of magnetic circuits.
Reluctance is a measure of the opposition a magnetic circuit presents to the flow of magnetic flux. is a significant parameter in evaluating the effectiveness of magnetic systems.
Reluctance, denoted by the symbol R, measures a magnetic circuit's opposition to magnetic flux.
The mathematical formula for reluctance is:
R = l / (μ × A)
Where:
R: Magnetic resistance (1/H)
l: Length of the magnetic path (m)
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
For example, with l = 0.2 m, μ = 4π × 10⁻⁷ H/m, and A = 0.01 m², the reluctance is approximately 1.59 × 10⁶ 1/H.
Reluctance is analogous to electrical resistance in DC circuits, making it a key parameter in designing magnetic circuits.
The mathematical formula for reluctance is:
R = l / (μ × A)
Where:
R: Magnetic resistance (1/H)
l: Length of the magnetic path (m)
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
For example, with l = 0.2 m, μ = 4π × 10⁻⁷ H/m, and A = 0.01 m², the reluctance is approximately 1.59 × 10⁶ 1/H.
Reluctance is analogous to electrical resistance in DC circuits, making it a key parameter in designing magnetic circuits.
Residual magnetism indicates the magnet's ability to retain its magnetic properties over time. It is a key parameter in evaluating the strength and performance of the magnet.
This occurs due to opposing magnetic fields generated by the magnets, causing them to repel each other. Is important in designing systems where avoiding contact between magnets is necessary.
Includes the use of ferromagnetic materials or magnetic conductors to guide the magnetic field. By designing an effective return path, system efficiency can be maximized, and magnetic losses minimized.
Litera: S
Shearing force, denoted by the symbol Fs, refers to the force required to displace a magnet along the contact surface in a direction parallel to the contact plane.
Shear force can be calculated using the formula:
Fs = F × tan(θ)
Where:
F: Pull force (N)
θ: Angle of the contact surface (rad)
The greater the angle, the higher the force required to move the magnet.
Shear force is a crucial factor in designing magnetic systems, particularly where high mechanical stability is required.
Shear force can be calculated using the formula:
Fs = F × tan(θ)
Where:
F: Pull force (N)
θ: Angle of the contact surface (rad)
The greater the angle, the higher the force required to move the magnet.
Shear force is a crucial factor in designing magnetic systems, particularly where high mechanical stability is required.
The south pole is one of the two fundamental magnetic poles of a magnet. The south pole of a magnet attracts the north pole of another magnet, demonstrating magnetic attraction.
This process involves arranging magnets in series or parallel configurations, enhancing the magnetic field. Stacking magnets is commonly employed in applications requiring high magnetic strength.
Litera: T
Tesla is a unit of measurement for magnetic flux density, describing the strength and intensity of a magnetic field. In practice, tesla is used to evaluate magnet performance and design precise magnetic systems.
Anisotropic magnets have a specific direction of magnetization, ensuring higher efficiency compared to isotropic magnets. Isotropic magnets are ideal for general applications due to their flexibility.
Litera: W
Weber is the unit of magnetic flux, representing the total number of magnetic field lines passing through a specific area. It is a critical parameter for evaluating and quantifying magnetic fields and flux in neodymium magnets.
The weight of a neodymium magnet is a critical factor influencing its applications. It can be easily calculated based on its density and volume using the formula:
m = ρ × V, where:
m - mass of the magnet (in grams or kilograms).
ρ - density of the magnet (typically 7.5 g/cm³).
V - volume of the magnet (in cm³ or m³).
For a magnet with a typical density of 7.5 g/cm³ and a volume of 10 cm³, the weight is:
m = 7.5 × 10 = 75 g.
Calculating the weight helps select the right magnet for specific applications.
m = ρ × V, where:
m - mass of the magnet (in grams or kilograms).
ρ - density of the magnet (typically 7.5 g/cm³).
V - volume of the magnet (in cm³ or m³).
For a magnet with a typical density of 7.5 g/cm³ and a volume of 10 cm³, the weight is:
m = 7.5 × 10 = 75 g.
Calculating the weight helps select the right magnet for specific applications.