MEIQING INDUSTRIAL GROUPFerrofluid · Ferrotec EMG Series
SELECTION GUIDE

Six steps from "I need a magnetic fluid"
to a specific grade number

Choosing a ferrofluid is mostly a process of elimination: carrier first, then magnetization, then viscosity, then the boundaries you cannot cross. The whole walk-through takes about ten minutes, and you can hand it to us halfway through.

Send me your conditions See all 26 grades
THE SIX STEPS

Six steps to a grade number

Work through them in order — later steps cannot be decided before earlier ones

1. What is the medium?Oil, water, or a solvent you specify. Oil-based when you do not want the carrier to evaporate or mix; water-based when you want fast evaporation or need to bring particles into an aqueous system; dry powder when you want to disperse into your own solvent.
2. What must the magnetic response be?Saturation magnetization (Ms) drives how strongly the fluid responds. Higher Ms means stronger response and stiffer spikes, but usually higher viscosity. Typical research work sits between 100 and 440 Gs.
3. How thin must it flow?Viscosity matters when the fluid has to enter a small gap, wick, or be dispensed. Low viscosity (under 10 cP) for fine gaps and coating; higher viscosity where you want the fluid to stay put.
4. What temperature range?Pour point and flash point bound the usable window. If you are near either limit, say so up front — this eliminates grades faster than anything else.
5. What must not happen?No evaporation, no mixing with a neighbouring medium, no particle residue after drying, no ionic contamination. State the prohibitions explicitly; they are the most common cause of a wrong order.
6. How much, and by when?Standard grades start at 10 mL. In-stock grades typically ship in 3–5 business days; non-stock grades follow the Ferrotec channel lead time, confirmed in writing before order.
DECISION TABLE

The three carriers at a glance

Your conditionPickWhy
Carrier must not evaporateOil-basedLight hydrocarbon carrier, viscosity close to water, stable over long storage
Carrier should evaporate / aqueous systemWater-basedDeionized water carrier; the mainstream choice for biomedical and IVD work
You need your own solventDry powderSurface-coated Fe3O4 powder you disperse yourself; maximum formulation freedom
Demonstration, exhibit or teachingEFH seriesEFH1 / EFH3, clear spikes, pour point −94 °C, designed for display bottles and STEM kits
You need to transmit torque or forceNeitherFerrofluid transmits little force. You are probably looking for magnetorheological fluid (MRF), which is a different material and not supplied by us
The single most common mistake Ordering by saturation magnetization alone. Two grades with the same Ms can behave completely differently in your device because of carrier, surfactant and viscosity. Give us the medium, the geometry and the prohibitions — not just a number.

Send four numbers, get a grade

Medium, target magnetization, viscosity limit, temperature range. We reply with a specific grade or tell you ferrofluid is the wrong material.

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