Rated to 230°C (446°F), Maximum Coercivity
We offer Custom AH (High Intrinsic Coercivity) Series Neodymium Magnets.
They are the ideal choice for extreme thermal and magnetic stress up to 230°C.
The AH Series represents the top tier of Neodymium performance.
Standard magnets succumb to heat at 80°C.
And EH grades stop at 200°C.
But the AH Series has a heavy Dysprosium/Terbium alloy mix to achieve massive Intrinsic Coercivity (Hcj).
This makes the magnet virtually immune to demagnetization.
Even when subjected to the intense heat and opposing magnetic fields found in high-performance motorsport and aerospace actuators.
Why Choose AH Grade?
When failure is expensive, AH is the insurance policy.
1. Surviving the “Knee” (Demagnetization Resistance):
The Science:
In high-speed motors, the opposing magnetic field tries to “push” the magnet’s polarity backwards.
If the magnet gets hot, it becomes weak and flips polarity (demagnetizes).
The AH Advantage:
AH magnets have the highest resistance to this reversal of any Neodymium grade.
If your motor runs hot and pushes the magnet to its limit, AH holds the line where other grades fail.
2. The SmCo Alternative:
The Comparison:
At 230°C, the only other option is Samarium Cobalt.
But SmCo is brittle and prone to cracking under vibration.
The Benefit:
AH Neodymium allows you to keep the mechanical toughness of Neo (it doesn’t chip as easily).
And also survive temperatures that used to require SmCo.
Available Grades (AH Series)
We custom manufacture AH magnets to your specific shape.
Note that to achieve such high heat resistance, the raw magnetic pull (Br) is slightly lower than standard N52.
30AH: The most stable option. Max heat resistance.
33AH: The industry standard for high-temp servo motors.
35AH: High performance. Good balance of flux and heat resistance.
38AH: Premium power. Used in high-end EV and Hybrid racing motors.
Coating Advisory: High-Temp Finishes
At 230°C, the coating is the weak link.
You must choose carefully.
Phosphating (Passivation):
Highly Recommended.
This is a chemical conversion coating (grey color).
It does not melt, peel, or blister at 230°C.
It is the best choice for magnets glued onto steel rotors.
Uncoated (Bare):
Often used in hermetically sealed environments (like vacuum pumps) to prevent any outgassing.
Nickel (Ni-Cu-Ni):
Acceptable, but can discolor at these temperatures.
Avoid:
Do not use Epoxy or Zinc.
They will fail before the magnet does.
Ideal Applications
Motorsport (KERS): Kinetic Energy Recovery Systems in racing cars where heat spikes are extreme.
Aerospace: Fuel pump actuators and control surface motors.
Downhole Tools: Sensors for oil & gas drilling (shallow to medium depth).
Magnetic Bearings: High-speed flywheels requiring zero-contact support.
Ordering Guide
To get a precise quote for AH magnets, please define:
1). Dimensions: Length x Width x Thickness (or Drawing).
2). Grade: e.g., “35AH”.
3). Temperature: “What is the peak temperature?” (If it exceeds 230°C, you must look at our TH series or SmCo).
4). Application: “Is this for a motor rotor?” (If yes, we can discuss Laminated Magnets to reduce eddy current heat).
