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Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets
Cylinder SmCo Magnets

Cylinder SmCo Magnets

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Description

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Product Overview
 

Cylinder SmCo Magnets

 

Cylinder SmCo magnets, also called samarium cobalt rod magnets or round SmCo magnets, are high-performance rare earth permanent magnets designed for high-temperature, corrosion-resistant and precision magnetic applications. Their cylindrical geometry provides a concentrated magnetic field, stable axial or diametrical magnetization, and easy integration into sensors, actuators, couplings, medical devices and compact motor assemblies.

Compared with NdFeB magnets, SmCo magnets provide lower maximum magnetic energy but much stronger thermal stability, excellent resistance to demagnetization and naturally good corrosion resistance. Cylinder SmCo magnets are especially suitable for aerospace, automotive, downhole, medical, vacuum and high-speed applications where long-term magnetic reliability is more important than maximum room-temperature pull force.

Ningbo Vanguard Technologies supplies cylinder magnets across SmCo 1:5 and SmCo 2:17 grade families. Diameter, length, chamfer, tolerance, surface finish and magnetization direction can be customized according to your drawing. Prototype samples can usually be prepared within 10-15 days after grade, dimensions and magnetization are confirmed.

Quick View

Cylinder SmCo Magnet Selection Snapshot

 
SmCo5 / Sm2Co17
Available Grade Families
SmCo 1:5 and 2:17 grades support high-temperature cylinders, sensor rods and precision magnetic assemblies.
250-350 °C
High Temperature Stability
Stable output for aerospace, automotive, downhole, vacuum and high-speed rotating environments.
D / L
Cylinder Geometry Control
Diameter, length, chamfer, roundness, flatness and precision grinding tolerance can be customized.
10-15 Days
Prototype Sample Lead Time
Fast sampling after drawing, grade, tolerance and magnetization direction are confirmed.
Temperature Grade Guide
SmCo5
 
250 °C
Sm2Co17
 
300 °C
High Hcj
 
320 °C
High Temp
 
350 °C
Application Demand Focus
Aerospace
 
Stability
Automotive
 
Heat resistance
High-Temperature Sensors
 
High speed
Sensors
 
Signal stability
Vacuum Pumps
 
Corrosion
1Drawing ReviewDiameter, length, chamfer, tolerance
2Grade MatchBr, Hcj, thermal stability
3Machining PlanGrinding, slicing, end-face finish
4MagnetizationAxial, radial, diametrical, multi-pole
5InspectionFlux, size, polarity, appearance
Industries Served
 
 

Key Applications

 
Aerospace & Aviation
In aerospace and aviation, cylinder SmCo magnets are critical for satellite reaction wheels (attitude control), missile guidance actuators, and radar systems. They operate reliably in space (vacuum, cosmic radiation, cryogenic temperatures) and military-grade shock/vibration, while their lightweight, compact design meets strict weight constraints. Their inherent corrosion resistance eliminates the need for protective coatings in harsh atmospheres.
Automotive 
In electric vehicles (EVs) and advanced automotive systems, cylinder SmCo magnets complement neodymium in high-temperature sections of traction motors, preventing demagnetization during fast charging. They also power high-temperature sensors for turbochargers and EGR systems, where temperatures exceed 200°C, ensuring safety and performance.
Industrial Motors
Cylinder SmCo magnets are used in BLDC motors, servo motors, and generators for high-heat environments (e.g., downhole oil drilling, industrial furnaces, aerospace actuators). Unlike neodymium magnets, they retain over 95% of their magnetic strength at 300–350°C, while their cylindrical shape delivers a stable magnetic field that reduces torque ripple and vibration in high-speed rotors. The compact cylindrical form supports easy insertion into housings, fixtures or sensor carriers, enabling compact, high-power designs.
High-Temperature Sensors & Levitation Systems
Cylinder SmCo magnets enable non-contact magnetic bearings in turbochargers, vacuum pumps, and flywheel energy storage systems. They generate stable axial/radial fields to levitate shafts, eliminating friction and wear, and supporting rotational speeds up to 100,000 RPM. Their thermal stability and rigidity withstand high centrifugal forces, making them ideal for frictionless, energy-efficient high-speed applications.
Medical & Scientific Instruments
Cylinder SmCo magnets are used in MRI equipment, surgical robots, and NMR spectrometers. They are biocompatible and inert to bodily fluids, suitable for medical devices, and retain magnetic performance at near-absolute zero (-273°C) for cryogenic research. Their precision magnetic fields enable high-resolution imaging and micron-level actuation in surgical robots.
Power Generation
Cylinder SmCo magnets are used in BLDC motors, servo motors, and generators for high-heat environments (e.g., downhole oil drilling, industrial furnaces, aerospace actuators). Unlike neodymium magnets, they retain over 95% of their magnetic strength at 300–350°C, while their cylindrical shape delivers a stable magnetic field that reduces torque ripple and vibration in high-speed rotors. The compact cylindrical form supports easy insertion into housings, fixtures or sensor carriers, enabling compact, high-power designs.
Magnetic Performance
 

Grade & Magnetic Properties

 

Standard grades for cylinder SmCo magnets. All values at 20 °C. Values are typical; exact grade selection is confirmed per application temperature, magnetic circuit, demagnetizing field, and assembly requirements.

Material Grade Remanence Coercivity Intrinsic Coercivity Max. Energy Product Curie Temp. Max. Ope. Tem. Temp. Coeff. of Br Temp. Coeff. of Hcj
Br Hcb Hcj (BH)max Tc Tw
T kGs kA/m kOe kA/m kOe kJ/m³ MGOe (°C) (°C) (%/°C) (%/°C)
SmCo5 SmCo5-16S 0.79–0.84 7.9–8.4 620–660 7.8–8.3 ≥1830 ≥23.0 118–135 15–17 750 250 −0.035 −0.28
SmCo5-18S 0.84–0.89 8.4–8.9 660–700 8.3–8.8 ≥1830 ≥23.0 135–151 17–19 750 250 −0.040 −0.28
SmCo5-20S 0.89–0.93 8.9–9.3 684–732 8.6–9.2 ≥1830 ≥23.0 150–167 19–21 750 250 −0.045 −0.28
SmCo5-22S 0.92–0.96 9.2–9.6 710–756 8.9–9.5 ≥1830 ≥23.0 167–183 21–23 750 250 −0.045 −0.28
SmCo5-24S 0.96–1.00 9.6–10.0 740–788 9.3–9.9 ≥1830 ≥23.0 183–199 23–25 750 250 −0.045 −0.28
LTC(SmCo5-10) 0.62–0.66 6.2–6.6 485–517 6.1–6.5 ≥1830 ≥23.0 75–88 9.5–11.0 750 300 20–100 °C +0.0156%/°C
100–200 °C +0.0087%/°C
200–300 °C +0.0007%/°C
Sm2Co17 Sm2Co17-24H 0.95–1.02 9.5–10.2 692–764 8.7–9.6 ≥1990 ≥25.0 175–191 22–24 800 350 −0.025 −0.20
Sm2Co17-26H 1.02–1.05 10.2–10.5 740–788 9.4–10.0 ≥1990 ≥25.0 191–207 24–26 800 350 −0.030 −0.20
Sm2Co17-28H 1.03–1.08 10.3–10.8 756–812 9.5–10.2 ≥1990 ≥25.0 207–220 26–28 800 350 −0.035 −0.20
Sm2Co17-30H 1.08–1.10 10.8–11.0 788–835 9.9–10.5 ≥1990 ≥25.0 220–240 28–30 800 350 −0.035 −0.20
Sm2Co17-32H 1.10–1.13 11.0–11.3 812–860 10.2–10.8 ≥1990 ≥25.0 230–255 29–32 800 350 −0.035 −0.20
Sm2Co17-22 0.93–0.97 9.3–9.7 676–740 8.5–9.3 ≥1433 ≥18.0 160–183 20–23 800 300 −0.020 −0.20
Sm2Co17-24 0.95–1.02 9.5–10.2 692–764 8.7–9.6 ≥1433 ≥18.0 175–191 22–24 800 300 −0.025 −0.20
Sm2Co17-26 1.02–1.05 10.2–10.5 748–796 9.4–10.0 ≥1433 ≥18.0 191–207 24–26 800 300 −0.030 −0.20
Sm2Co17-28 1.03–1.08 10.3–10.8 756–812 9.5–10.2 ≥1433 ≥18.0 207–220 26–28 800 300 −0.035 −0.20
Sm2Co17-30 1.08–1.10 10.8–11.0 788–835 9.9–10.5 ≥1433 ≥18.0 220–240 28–30 800 300 −0.035 −0.20
Sm2Co17-32 1.10–1.13 11.0–11.3 812–860 10.2–10.8 ≥1433 ≥18.0 230–255 29–32 800 300 −0.035 −0.20
Sm2Co17-26M 1.02–1.05 10.2–10.5 676–780 8.5–9.8 955–1433 12–18 191–207 24–26 800 300 −0.035 −0.20
Sm2Co17-28M 1.03–1.08 10.3–10.8 676–796 8.5–10.0 955–1433 12–18 207–220 26–28 800 300 −0.035 −0.20
Sm2Co17-30M 1.08–1.10 10.8–11.0 676–835 8.5–10.5 955–1433 12–18 220–240 28–30 800 300 −0.035 −0.20
Sm2Co17-32M 1.10–1.13 11.0–11.3 676–852 8.5–10.7 955–1433 12–18 230–255 29–32 800 300 −0.035 −0.20
Sm2Co17-24L 0.95–1.02 9.5–10.2 541–716 6.8–9.0 636–955 8–12 175–191 22–24 800 250 −0.025 −0.20
Sm2Co17-26L 1.02–1.05 10.2–10.5 541–748 6.8–9.4 636–955 8–12 191–207 24–26 800 250 −0.035 −0.20
Sm2Co17-28L 1.03–1.08 10.3–10.8 541–764 6.8–9.6 636–955 8–12 207–220 26–28 800 250 −0.035 −0.20
Sm2Co17-30L 1.08–1.15 10.8–11.5 541–796 6.8–10.0 636–955 8–12 220–240 28–30 800 250 −0.035 −0.20
Sm2Co17-32L 1.10–1.15 11.0–11.5 541–812 6.9–10.2 636–955 8–12 230–255 29–32 800 250 −0.035 −0.20
LTC(Sm2Co17-18) 0.85–0.90 8.5–9.0 629–708 7.9–8.9 ≥1433 ≥18 135–151 17–19 840 300 −0.001 −0.25
LTC(Sm2Co17-20) 0.90–0.94 9.0–9.4 661–732 8.3–9.2 ≥1433 ≥18 151–167 19–21 840 300 −0.007 −0.25
LTC(Sm2Co17-22) 0.94–0.97 9.4–9.7 685–740 8.6–9.3 ≥1433 ≥18 167–183 21–23 840 300 −0.010 −0.25
LTC(Sm2Co17-24) 0.98–1.02 9.8–10.2 724–772 9.1–9.7 ≥1433 ≥18 183–199 23–25 840 300 −0.012 −0.25
Typical Physical Properties (All Sintered SMCO Grades)
Parameters Unit SmCo5 Sm2Co17
Density / ρ g/cm³ 8.2–8.4 8.3–8.5
Vickers Hardness / HV – 450–500 550–600
Compressive Strength MPa 1000 800
Bending Strength / σ MPa 150–180 130–150
Tensile Strength / σ MPa 400 350
Electrical Resistivity / ρ Ω·cm (5–6) × 10−5 (8–9) × 10−5
Coefficient of Thermal Expansion / α   C⊥ 10−6/K C⊥: 12 C⊥: 11
C∥: 6 C∥: 8
Magnetization Orientations Available

Surface Treatment
 

Coating & Plating Options

 
Coating of cylinder SmCo Magnets: While cylinder SmCo magnets inherently possess excellent corrosion resistance (thanks to their low iron content, unlike NdFeB magnets), optional surface coatings are recommended for specific harsh operating environments to further enhance durability and performance stability. The choice of coating is closely matched to the application scenario, ensuring compatibility with the magnet’s high-temperature resistance and dimensional precision.
Coating Type
Thickness / Colour
Salt Spray · Tw
Ni·Cu·Ni Triple Layer
Industry standard for clean, low-humidity environments. Bright silver finish.
Most Popular
10–20 μm · Bright Silver
≥ 48 hr · ≤ 200 °C
Zinc (Zn)
Cost-effective general-purpose coating. Dark silver finish. Good for most industrial motors.
5–10 μm · Dark Silver
≥ 24 hr · ≤ 160 °C
Epoxy Resin
Best corrosion and humidity resistance. Charcoal grey. Recommended for EV motor environments.
EV Preferred
10–20 μm · Char Grey
≥ 72 hr · ≤ 120 °C
Ni·Cu + Epoxy
Triple-layer protection for high-humidity and aggressive environments.
12–25 μm · Matt Black
≥ 168 hr · ≤ 120 °C
Geometry & Tolerances
 

Dimension Capability

 

Cylinder magnets are defined by diameter (D) and length (L). Standard tolerance is ± 0.05 mm; tight-tolerance ± 0.03 mm can be discussed for precision-ground parts. Chamfer, flatness, roundness, parallelism, surface finish and matched-set sorting can be controlled according to assembly requirements.

Dimension Minimum Maximum Standard Tol.
Diameter (D) 1.0 mm 120 mm ± 0.05 mm
Length (L) 0.5 mm 150 mm ± 0.05 mm
Chamfer Optional Per drawing Project-based
Design Support

How to Specify Cylinder SmCo Magnets

 
Grade Selection
SmCo5 is suitable for stable output and excellent temperature coefficient control. Sm2Co17 is selected for higher energy product, higher working temperature, and stronger demagnetization resistance.
Cylinder Geometry
Diameter, length, wall thickness, concentricity, roundness, chamfer, and chamfered features should be confirmed together, especially for sensor, actuator and high-temperature assemblies.
Magnetization Direction
Axial, radial, diametrical, multi-pole, and custom magnetization patterns can be supplied. Magnetization drawing or pole mark should be confirmed before sampling.
Custom Manufacturing

Available Custom Features

 
Item
Options
Typical Use
Geometry
Cylinder, rod, short disc, long rod, stepped cylinder, chamfered cylinder and precision-ground cylinder.
Sensor, actuator, coupling, medical instrument, aerospace device, downhole tool and high-temperature fixture.
Tolerance Control
Diameter/length tolerance, concentricity, roundness, parallelism, height matching, surface flux grouping, and batch sorting.
High-speed rotors, low-vibration assemblies, precision shafts, automated bonding, sensor calibration.
Surface Treatment
Uncoated, passivation, NiCuNi, epoxy, parylene, or application-specific coating after evaluation.
High humidity, chemical exposure, bonding process, clean assembly environment.
Production Control

Manufacturing & Quality Assurance

 

Cylinder SmCo magnets are produced through alloy preparation, powder milling, magnetic-field pressing, vacuum sintering, aging heat treatment, core drilling or EDM, ID/OD grinding, slicing, optional coating, magnetization, and final inspection. The process is controlled to maintain magnetic stability, diameter accuracy, and reliable assembly fit.

Magnetic Inspection
Br, Hcb, Hcj, (BH)max, surface flux, pole direction, multi-pole distribution, and batch consistency can be tested according to drawing or project specification.
Dimensional Inspection
Diameter, length, wall thickness, concentricity, roundness, parallelism, chamfer, hole position, and coating thickness are checked before packing.
Documentation
Material certificate, dimensional report, coating report, salt spray result, thermal aging data, and RoHS/REACH documents are available on request.
Fast Quotation

Information Needed for Fast Quotation

 

For faster engineering review, please provide drawing or 3D file, Diameter, length, tolerance, chamfer or chamfered requirement, grade or working temperature, magnetization direction, coating requirement, operating environment, sample quantity, and annual volume. If the grade is not fixed, our team can recommend a SmCo5 or Sm2Co17 option based on temperature and required magnetic output.

Support
 

Frequently Asked Questions

 
When should I choose a cylinder SmCo magnet over a cylinder NdFeB magnet?
Choose cylinder SmCo if your application requires high-temperature operation, superior corrosion resistance, low magnetic drift, or resistance to demagnetization in harsh environments such as vibration, chemical exposure or downhole conditions.
What is the minimum order quantity for custom cylinder magnets?
For custom geometry, samples can be arranged from as few as 50–200 pieces. Mass-production MOQ is typically 1000–10000 pieces per specification, though this is flexible depending on magnet size and grade. Contact us to discuss your project volume.
Can you supply cylinder magnets for sensor or actuator assemblies?
Yes. Vanguard can supply bare cylinder magnets, matched magnetic sets, polarity-marked parts and assembly-ready components depending on your manufacturing flow.
Do you provide material certifications and test reports?
Full material certificates (chemical composition, magnetic test data, coating thickness, salt-spray results) are provided with each shipment as standard. ROHS, REACH, and conflict-mineral declarations are available on request.
What is the lead time for cylinder SmCo magnets?
Prototype samples: 10–15 working days. Mass-production orders: 25–35 working days depending on grade, coating, and quantity. Rush sampling may be available — please inquire.
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