When engineers need a magnet that can withstand heat, corrosion, vibration, and demanding operational environments, two materials typically top the shortlist: samarium-cobalt (SmCo) and high-temperature neodymium (NdFeB).

Both are rare-earth magnets, but their performance characteristics differ in essential ways. 

Samarium cobalt offers exceptional temperature stability (up to 350°C+), inherent corrosion resistance, and long-term magnetic reliability. It’s the preferred choice for aerospace, defense, high-heat motors, sensors, and corrosive environments where coating failure is a concern.

High-temperature neodymium delivers the strongest magnetic performance in the smallest volume, typically operating reliably below 200–220°C. It’s more cost-effective, easier to source, and ideal for compact motors, actuators, robotics, medical devices, and general industrial applications.

This guide breaks down the engineering, material science, and application considerations behind samarium cobalt vs high-temperature neodymium.

Samarium Cobalt vs. High-Temp Neodymium: Engineering Comparison Chart

Category Samarium Cobalt (SmCo) High-Temp Neodymium (NdFeB)
Typical Operating Temperature 250°C–350°C 150°C–220°C
Maximum Temperature Before Irreversible Loss Up to 550°C (grade-dependent) Up to ~230–240°C (EH/SH grades)
Magnetic Strength (Energy Product) Medium–High (20–32 MGOe) Very High (up to 52 MGOe)
Corrosion Resistance Excellent without coating Fair; requires protective coatings (Ni-Cu-Ni, epoxy, Parylene)
Demagnetization Resistance Very high, even at elevated temperatures Good at room temp; decreases under heat
Mechanical Robustness More brittle; chips easily Stronger mechanically, but still brittle
Thermal Stability Exceptional Moderate to high depending on grade
Cost & Availability Higher cost; geopolitical supply constraints Lower cost; generally easier to source
Best Environments Extreme heat, corrosive conditions, vacuum, aerospace High-strength applications with limited space

 

Recommended Use Cases

Use Samarium Cobalt When:

  • Your system exceeds 200–250°C regularly 
  • Components face corrosion, steam, or chemicals 
  • You need long-term magnetic stability 
  • Coatings are not viable or pose risk 
  • Applications include aerospace, high-temp motors, and sensors 

Use High-Temp Neodymium When:

  • You need maximum magnetic strength in the smallest size 
  • Temperatures remain below 200–220°C 
  • Cost and efficiency matter 
  • Coatings can be applied for protection 
  • Applications include BLDC motors, robotics, actuators, medical devices, and compact assemblies 

Quick Decision Guide

If your top priority is… Choose
Extreme heat tolerance Samarium Cobalt
Maximum magnetic strength High-Temp Neodymium
Corrosion resistance Samarium Cobalt
Lowest cost for strong output High-Temp Neodymium
Compact, lightweight designs High-Temp Neodymium
Lifetime stability in harsh environments Samarium Cobalt


Apex Magnets Offers Expert Guidance 

At Apex Magnets, our engineering team works closely with businesses to determine whether samarium cobalt or high-temperature neodymium is the right fit for their specific application. We evaluate performance requirements, thermal conditions, environmental factors, and size constraints to help you choose the most reliable material for long-term use. Thanks to our strong relationships with global manufacturing partners, we can source specialty grades even when market conditions tighten or other suppliers face shortages. If you need support selecting the right magnet or customizing a component, we invite you to contact our team or submit a Custom Order Request.

 

Magnets can be dangerous. Neodymium magnets, especially, must be handled with care to avoid personal injury and damage to the magnets. Fingers and other body parts can get severely pinched between two attracting magnets. Bones can be broken by larger magnets. 

 

Visit our Magnet Safety page to learn more.