Littelfuse H40 H-40 Series NdF...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$0.85
Littelfuse H40 H-40 Series NdFeB 45H Permanent Magnet

Littelfuse H40 H-40 Series NdFeB 45H Permanent Magnet

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Model: H40

In Stock (leaves warehouse same day if ordered before 3pm ET)

$0.85
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Littelfuse H-40 Series NdFeB 45H Permanent Magnet

The Littelfuse H-40 Series is a permanent magnet manufactured from NdFeB 45H neodymium-iron-boron material, engineered to deliver strong, stable magnetic performance in demanding electrical and sensing environments. This high-energy magnet grade provides a magnetic coercivity of 11,800 Oersted and a retentivity of 13,300 Gauss, giving the H-40 Series the field strength and resistance to demagnetization required for reliable long-term operation in electrical assemblies. The magnet carries a maximum operating temperature rating of 120°C, making it well suited for use in equipment and enclosures that experience elevated ambient or operating temperatures. Littelfuse designs the H-40 Series to provide OEMs and electrical integrators with a consistent, high-performance magnetic component for demanding installations.

Key Features

  • Magnet Material: NdFeB 45H neodymium-iron-boron composition delivers a high magnetic energy density in a compact form factor.
  • Magnetic Coercivity: Rated at 11,800 Oersted, giving the H-40 Series strong resistance to demagnetization from external fields or thermal exposure.
  • Magnetic Retentivity: 13,300 Gauss retentivity supports a consistent, stable magnetic field output over the life of the component.
  • Max Operating Temperature: Rated to 120°C, allowing use in elevated-temperature electrical and industrial environments without loss of magnetic performance.
  • H-40 Series Platform: Part of the Littelfuse H-40 magnet series, engineered for repeatable, dependable performance in OEM and industrial equipment designs.
  • High-Energy NdFeB Grade: The 45H grade is formulated for a strong balance of magnetic strength and thermal stability compared to lower-grade magnet materials.

Technical Specifications

  • Max Operating Temp (°C): 120
  • Magnet Material: NdFeB 45H
  • Magnet Coercivity: 11,800 Oersted
  • Magnet Retentivity: 13,300 Gauss

Typical Applications

  • OEM Electrical and Electromechanical Assemblies
  • Industrial Equipment and Machinery Manufacturing
  • Magnetic Position and Field-Sensing Components
  • Elevated-Temperature Operating Environments up to 120°C
  • Electrical Component Design and Integration

Why Littelfuse?

Littelfuse engineers the H-40 Series magnet from NdFeB 45H material to deliver dependable magnetic performance, backed by measured coercivity and retentivity ratings that support consistent field strength throughout the component's operating life. With a 120°C maximum operating temperature rating, this magnet is built to perform reliably in demanding electrical and industrial environments where lower-grade magnets may lose strength. Choose Littelfuse for magnetic components engineered for dependable, long-term performance in professional electrical applications.

Manufacturer Resources

Littelfuse Product Catalog

Product Specs

Product Type:
Magnet
Grade:
45H
Series:
H-40
Product Material:
NdFeB
Department:
Electrical
Product Group:
Wiring Devices

Littelfuse H40 – Frequently Asked Questions

1) What temperature can the Littelfuse H-40 magnet handle before it loses strength?
The H-40 Series NdFeB magnet is rated to a maximum operating temperature of 120 degrees C. That covers most enclosure and industrial ambient conditions, but it is a hard ceiling: if your assembly runs hotter than 120 C at the magnet location, this grade is the wrong choice and you need a higher-temperature magnet grade. Measure at the magnet, not at the cabinet air, since mounting near a heat sink or power device can push local temperature well above ambient.
2) What does the 45H grade mean on this Littelfuse neodymium magnet?
45H is the NdFeB material grade: the 45 refers to the magnetic energy product class and the H suffix designates the higher-temperature variant of that class. On the H-40 Series that translates into a coercivity of 11,800 Oersted and a retentivity of 13,300 Gauss, with a 120 C maximum operating temperature. Coercivity is the number that matters if the magnet sits near other field sources, since it is the resistance to being demagnetized by an external field.
3) Is the Littelfuse H40 magnet strong enough for a position or proximity sensing application?
For magnetic position and field-sensing work, the number to design against is the 13,300 Gauss retentivity, which is the residual flux density of the 45H material itself, not the flux at a distance from a given magnet shape. Pair that with the 11,800 Oersted coercivity and you get a field that stays stable over the component's service life rather than drifting as the assembly heats and cools within its 120 C range. Sensing gap and trip point still depend on your magnet geometry and the sensor's operate point, so size the gap against your sensor's published Gauss threshold.
4) What part number do I order for the Littelfuse H-40 Series magnet?
There is a single orderable part: Littelfuse manufacturer part number H40, the H-40 Series NdFeB 45H permanent magnet. No handing, size, or finish options to specify. Reference it as H40 on a purchase order or a bill of materials.
5) Is a neodymium magnet like the Littelfuse H40 the right choice, or should I use a ferrite magnet?
NdFeB is the pick when you need a strong field out of a small part. Neodymium-iron-boron carries far higher energy density than ferrite or alnico, which is why the H-40 Series delivers 13,300 Gauss retentivity in a compact body. The trade-off is temperature: this magnet stops at 120 C, so if your equipment runs hotter, or if it sits in a wet or corrosive environment where an uncoated rare-earth magnet would corrode, ferrite is the more forgiving material even though you give up field strength. For OEM electrical assemblies and industrial machinery inside that thermal window, the NdFeB 45H grade is the stronger option.
6) Will the Littelfuse H40 magnet weaken over time in an industrial machine?
Demagnetization resistance is what the 11,800 Oersted coercivity rating buys you. That figure is the material's ability to hold its field against external magnetic fields and thermal exposure, which is the usual cause of a magnet going soft in a machine over years of service. Kept within the 120 C maximum operating temperature and away from opposing fields strong enough to exceed that coercivity, the 45H grade holds a consistent output.
How fast can I get the Littelfuse H40 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Littelfuse H40 come with a warranty?
Absolutely. The Littelfuse H40 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Littelfuse H40?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Littelfuse H40 from ZenSupply?
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