Mainrich International

Articles & Industry Insights

In-depth analysis of the magnet technologies powering robotics, electric vehicles, and high-performance motors. Written for engineers, sourcing teams, and decision-makers.

Sourcing

NdFeB Magnet Tolerances: Dimensional Specs, Surface Finish, and What to Put on Your Drawing

Standard sintered NdFeB tolerances are +/-0.05 mm on ground dimensions and +/-0.1 mm on as-sintered surfaces. Tighter specs are achievable but cost real money. This guide maps tolerance grades to manufacturing processes, explains what actually drives cost, and shows how to write a magnet drawing that gets you accurate quotes.

May 27, 2026
NdFeB magnet tolerancesmagnet dimensional specificationsmagnet surface finish
Technical

NdFeB Thermal Demagnetization: Temperature Limits and Grade Selection for EV and Robotics Motors

Every NdFeB grade has an irreversible demagnetization knee that shifts upward with temperature. Cross that knee during a hot-cell torque test or a stalled rotor event and the magnet loses flux permanently. This guide maps the thermal ceiling for each grade family, explains how to read a demagnetization curve at operating temperature, and shows where H, SH, UH, and EH grades earn their price premium.

May 27, 2026
NdFeB thermal demagnetizationmagnet temperature limitsirreversible flux loss
Technical

NdFeB Magnet Segmentation: Cutting Eddy-Current Losses in EV and Humanoid Motors

Sintered NdFeB has a resistivity of roughly 140 microhm-cm, so a solid magnet inside a high-frequency rotor field acts like a shorted secondary. The fix is axial and circumferential segmentation, but the segmentation that actually works is narrower than the textbook suggests. Here is how to specify it in an RFQ, what it costs, and where the thermal feedback loop breaks down without it.

May 19, 2026
NdFeB magnet segmentationmagnet eddy current lossIPM motor rotor design
Compliance

Section 301 25% Tariff on Chinese NdFeB Magnets: What US Buyers Should Price Into 2026 Quotes

On 1 January 2026 the longstanding Section 301 exemption for permanent magnets ended. Imports of NdFeB and SmCo magnets from China now carry an additional 25% USTR duty on top of the 2.1% MFN base rate. Here is how to read the tariff stack, run a landed-cost example, and structure 2026 POs so the duty stops being a surprise.

May 5, 2026
Section 301 tariff NdFeBpermanent magnet tariff 2026HTS 8505.11 NdFeB
Market Update

Rare Earth Market Update: May 2026 — NdPr Pricing, MOFCOM Licensing, and Western Supply

NdPr oxide opened 2026 at $53/kg and crossed $135/kg in late April — up roughly 155% YTD. MP Materials produced its first commercial-scale magnets, Neo Estonia commissioned its HREE line, USA Rare Earth ramped Stillwater, and the MOFCOM suspension clock is now six months from expiry. Here is what that means for procurement teams in the next 30–60 days.

May 1, 2026
rare earth market updateNdPr price May 2026dysprosium terbium price
Compliance

EU Critical Raw Materials Act: What 2026 Compliance Means for OEMs Sourcing NdFeB Magnets

The Council adopted its CRMA position in March 2026. The Commission has until November 2026 to set the magnet label format, and by May 2027 any product containing more than 0.2 kg of permanent magnets must disclose recycled-content shares for eight specified elements. Here is what European OEMs and their tier-1s need to do now to be ready.

April 28, 2026
EU Critical Raw Materials ActCRMA complianceNdFeB sourcing Europe
Industry Insight

NdFeB Magnets for US Humanoid Robotics: Figure, Tesla Optimus, Agility Digit, and the 2026 Supply Chain Reality

Tesla hit 1 million Optimus Gen 3 units/year capacity at Fremont in March 2026. Figure's BotQ facility is tooled for 12,000 Figure 03 units/year. Agility Digit is working in Amazon warehouses. Here is what engineers actually need to know about the magnets inside these machines and how to source them for US production programs.

April 21, 2026
US humanoid roboticsTesla Optimus magnetsFigure AI magnets
Buyer's Guide

How US and European Tier 1 Suppliers Qualify Chinese NdFeB Magnet Manufacturers: The 2026 Playbook

Tier 1 automotive, robotics, and industrial procurement teams have tightened qualification criteria since 2024. This is the practical, step-by-step playbook for qualifying a Chinese magnet manufacturer to production status — the documentation, the audits, the red flags, and the timeline that actually holds.

April 21, 2026
qualify Chinese NdFeB supplierTier 1 supplier qualificationIATF 16949 magnet supplier
Technical

NdFeB vs SmCo Magnets: Which Rare Earth Material to Choose for Your Motor, Actuator, or Sensor

Sintered NdFeB and SmCo (samarium-cobalt) are the two commercial rare earth magnet materials. They overlap substantially in use cases but win in different envelopes. This is a practical decision framework with real specification data — not a materials-science lecture.

April 21, 2026
NdFeB vs SmCoSmCo vs neodymiumsamarium cobalt magnets
Market Update

China Rare Earth Export Controls in 2026: MOFCOM Licensing, the November Cliff, and How to Keep NdFeB Magnet Shipments Moving

The November 2025 suspension did not end export licensing. The April 2025 rules remain fully in force, NdPr prices jumped 37% in April 2026, and the suspension window expires November 10, 2026. Here is what procurement teams need to know about MOFCOM licensing for NdFeB magnets right now.

April 21, 2026
rare earth export controls 2026MOFCOM export licenseNdFeB export controls
Technical

NdFeB Magnet Coatings Compared: NiCuNi vs Epoxy vs Zinc vs Parylene — Specification Guide with Salt Spray Data

The coating you choose affects corrosion life, bond strength, cost, and whether your magnet survives the environment it is going into. A practical engineering framework for selecting NdFeB coatings, with real test data and decision rules.

April 21, 2026
NdFeB coatingneodymium magnet coatingNiCuNi vs epoxy
Technical

Sintered vs Bonded NdFeB Magnets: How the Two Processes Differ and When to Use Each

Sintered and bonded NdFeB are often lumped together under the same 'neodymium magnet' label, but they are made by completely different processes and deliver very different performance. Here is how to tell them apart and pick the right one for your application.

April 20, 2026
sintered vs bonded NdFeBbonded neodymium magnetssintered NdFeB manufacturing
Buyer's Guide

Factory-Direct vs Trading Company: How to Verify Your NdFeB Magnet Supplier Actually Makes Magnets

A large share of the 'magnet manufacturers' procurement teams find online are trading companies. The difference matters for price, lead time, quality control, and export compliance. Here is how to tell them apart and why it matters more in 2026 than it used to.

April 20, 2026
factory direct NdFeB suppliertrading company vs manufacturerqualifying Chinese magnet suppliers
Technical

NdFeB Magnets in EV Traction Motors: Grades, Specifications, and What Engineers Need to Know

Every major EV traction motor uses NdFeB magnets embedded in an IPM rotor. Here is what goes into specifying those magnets correctly - from grade selection to thermal management to the role of GBD in reducing cost.

April 16, 2026
EV traction motor magnetsIPM motor NdFeBelectric vehicle magnets
Market Update

US Domestic Rare Earth Magnet Production Is Here - What It Means for Buyers in 2026

USA Rare Earth just shipped its first commercial NdFeB magnets from Oklahoma. MP Materials is building in Texas. Here is what domestic production actually delivers today, what it does not, and how procurement teams should factor it into their sourcing strategy.

April 16, 2026
US rare earth magnet productionUSA Rare EarthMP Materials magnets
Market Update

NdFeB Magnet Pricing in 2026 - What Buyers Should Expect and How to Plan

NdFeB magnet prices are up 30-50% year-over-year. Here is what is driving the increase, where prices are headed, and what procurement teams can do to protect their budgets.

April 13, 2026
NdFeB pricing 2026neodymium magnet costrare earth prices
Technical

NdFeB Magnet Grades Explained - N35 to N55 and What the Letters Mean

Every NdFeB magnet grade tells you exactly what to expect from it - if you know how to read the naming convention. Here is the practical breakdown engineers actually need.

April 11, 2026
NdFeB magnet gradesneodymium magnet gradesN52 magnet
Industry Insight

From Spring Festival Gala to Factory Floor: The Magnets Powering China's Humanoid Robot Boom

In 2025, Unitree's H1 robots danced on CCTV's Spring Festival Gala. In 2026, even more humanoid robots took the stage. Behind every fluid joint movement is a precision magnet - here's what's actually inside these machines.

February 15, 2026
humanoid robotsSpring Festival GalaUnitree H1
Buyer's Guide

How to Choose a Neodymium Magnet Supplier for Robotics and Servo Motors

A practical guide for robotics engineers and procurement teams evaluating magnet suppliers. What to look for, what to avoid, and why the right supplier is a competitive advantage.

February 10, 2026
neodymium magnet supplierrobotics magnetsservo motor magnets
Technical

Radial Multi-pole Rings vs. Segmented Arc Magnets: Which Is Better for Your Motor?

A technical comparison of the two dominant magnet architectures for BLDC and PMSM motors. Performance data, cost trade-offs, and application guidance.

February 1, 2026
radial multipole magnetssegmented arc magnetsBLDC motor magnets
Industry Insight

Magnets for Collaborative Robots (Cobots): Requirements, Grades, and Supplier Selection

Cobots are the fastest-growing segment in industrial robotics. Here's what cobot manufacturers need from their magnet supply chain.

January 25, 2026
collaborative robotscobot magnetscobot motor magnets
Technical

GBD Magnets Explained: How Grain Boundary Diffusion Cuts Costs Without Cutting Performance

Grain Boundary Diffusion is the most important magnet manufacturing innovation in a decade. Here's how it works, why it matters, and how it saves robotics, EV, and aerospace programs money.

January 15, 2026
GBD magnetsgrain boundary diffusionNdFeB manufacturing
Technical

The Complete Guide to Magnets for Humanoid Robot Actuators

Everything a robotics engineer needs to know about specifying, sourcing, and testing magnets for humanoid robot joint motors. From grade selection to incoming inspection.

January 5, 2026
humanoid robot actuatorsrobot joint motorsactuator magnets

Need Magnets for Your Robotics Project?

Our engineering team provides free design assistance for motor magnet selection and sourcing. From prototype to mass production.

Get Free Engineering Support