Ferrite Magnet
GX Magnet manufactures elongated sintered ferrite bar magnets to customer drawings for magnetic separation equipment, position-sensing and switching devices, holding fixtures and linear magnetic circuits. Length, cross-section, working faces, magnetization direction and finished-part magnetic output are reviewed together to match the assembly and operating requirements.
RFQ INPUT CHECKLIST
A complete drawing and specification package enables GX to select the pressing and magnetization route, assess tooling and inspection requirements, and prepare the quotation and sample plan on a consistent basis.
PRODUCT DEFINITION AND SUPPLY SCOPE
A ferrite bar magnet is an elongated rectangular or square permanent magnet produced by pressing and sintering hard-ferrite powder. Its extended pole face suits linear magnetic circuits used in holding, separating, sensing and actuation assemblies.
GX manufactures sintered strontium ferrite bars to customer drawings. Length, cross-section, straightness, working faces, edge condition, magnetic orientation and magnetization direction are reviewed with the required air gap and finished-part magnetic target before sampling.
TECHNICAL PARAMETERS FOR RFQ
Use the application and assembly conditions to define the material, cross-section, magnetization, interfaces and acceptance criteria. The approved drawing, specification, quotation and inspection plan then establish the requirements for sampling and recurring production.
| Parameter group | Project-specific review basis | Confirmation and Release Basis |
|---|---|---|
| Material / route | Sintered strontium ferrite; grade and isotropic or anisotropic orientation selected for the required field direction, operating temperature and magnetic circuit. | Approved grade and orientation recorded in the released specification; Br, Hcb, Hcj and (BH)max report provided when specified. |
| Geometry and tolerances | Length, width, thickness, straightness, flatness, parallelism, working faces, chamfers and edge or chipping limits. | Released drawing defines dimensions, datums and tolerances; first-article dimensional inspection confirms conformance. |
| Magnetic or functional requirement | Magnetization through the length, width or thickness; required polarity and finished-part field, flux, pull force or switch response at a defined position or air gap. | Approved sample report records the magnetic target, measurement position, air gap, fixture and test conditions. |
| Mechanical / assembly interface | Bonding, sleeve or holder interface; mating dimensions, locating datums, retention method and installed orientation. | Assembly drawing confirms the interface and retention requirements; fit or retention testing is completed when specified. |
| Operating environment | Operating temperature, thermal shock or cycling, moisture, vibration, impact, contact medium and installation condition. | Validation plan defines the applicable exposure conditions, test duration and acceptance criteria. |
| Inspection and acceptance | Dimensional and visual inspection plus the agreed magnetic or functional test under defined measurement conditions. | Control plan specifies the inspection method, gauge or fixture, sample size, frequency and lot-release records. |
| Supply boundary | Bar magnet only, or a sleeve, holder or separator assembly when included in the quotation. | Quotation and released drawing identify the supplied components and the included grinding, magnetization, inspection, packaging and documentation. |
Assembly interface
Sintered ferrite is hard and brittle. The assembly design must support the long bar without concentrating impact or bending load at one point.
Identify the bonding face, adhesive gap and surface condition. Do not assume the magnetic working face and bonding datum are interchangeable.
Share clips, slots, back plates or holders so contact points and clearance can be reviewed against the brittle ceramic body.
Avoid press-fit, point impact and forced bending unless the project has a validated fixture and acceptance method.
Cross-section, magnetic orientation and pressing direction are reviewed together because density distribution and the required pole faces cannot be separated.
Length-to-section ratio affects shrinkage and deformation risk. Straightness and end condition must be tied to an agreed datum and measurement setup.
Only functionally necessary faces should receive tight finishing controls. Long bars require stable support so grinding does not introduce bending load or edge damage.
Chamfers, allowable chip zones and critical ends are agreed from the assembly interface; zero visual chipping cannot be assumed for every brittle ferrite geometry.
Inspection and validation
The inspection and delivery plan separates geometry, working surfaces, magnetic acceptance, edge condition and transport protection so production is not released from a generic magnet specification.
| Control area | What is reviewed | Why it matters |
|---|---|---|
| Overall geometry | Length, width, thickness, squareness, radii and drawing datums | Supports assembly fit and repeatable positioning |
| Working surfaces | Flatness, parallelism, ground faces and bonding interfaces where specified | Controls the installed air gap and contact condition |
| Magnetic properties | Material or agreed magnetic target under a defined method | Connects the bar to the customer magnetic circuit |
| Polarity | Magnetization direction and north/south face identification | Prevents reversed installation or incorrect field direction |
| Edges and appearance | Chamfers, chips, cracks, surface condition and agreed acceptance limits | Reduces handling and assembly risk for brittle ferrite |
| Packaging interface | Part separation, supported spans, end protection, layer control and orientation marking where agreed | Protects brittle edges, working faces and long sections during export transport and unpacking |
Revision, datums, critical faces and special features remain traceable.
Dimensions, magnetization, magnetic acceptance and appearance are approved before release.
Recurring orders follow the released drawing, approved sample and agreed checks.
Geometry-led applications
Ferrite bar or rod geometry is useful when a mechanism needs an elongated magnetic body, defined pole locations, linear travel beside a sensor, or several magnetic elements arranged across a wide capture area. Final suitability still depends on the magnetic circuit, dimensions and magnetization specified for the assembly.
Match the bar length, cross-section, pole orientation and installed position to the coil or armature. Sample approval verifies mounting fit, pointer movement and the drawing-defined magnetic response.
Define polarity, magnetization direction, travel path and distance to the sensing element. Validate the switch-on and switch-off positions under the specified temperature, vibration and installation conditions.
Select the bar length, pole-face area and spacing to cover the material flow path. Confirm field or pull force at the working distance, together with retention and edge requirements.
Select a bar size and polarity that clearly demonstrate attraction, repulsion and magnetic field patterns. Confirm N/S marking, edge condition and magnetic response for repeatable experiments.
Documented industry presence
The exhibition record documents GX Magnet's participation in magnetic-material and motor-component industry events.
GX Magnet Exhibition Booth in Taizhou 2026. Event or visit photograph documenting the people and setting shown.
Documented evidence
GX uses documented quality-system controls and ferrite sample compliance reports as supporting evidence. The product drawing and agreed inspection specification remain the release basis for each bar magnet project.
Zhenjiang GX Magnet Co., Ltd. holds valid IATF 16949:2016 certification for the manufacturing of permanent ferrite magnet components.This certification covers all production‑oriented processes for ferrite magnet manufacturing.
Independent SGS laboratory testing delivers positive results for ferrite magnet samples under EU RoHS screening scope.
Independent SGS laboratory testing delivers positive screening results for ferrite magnet samples against REACH SVHC candidate‑list substances.
ENGINEERING AND SOURCING FAQ
Find practical answers on material selection, dimensional requirements, magnetization, operating conditions, inspection and the information needed for an accurate quotation.
The main differences are the material route, achievable geometry, magnetic output and assembly method. Compare them in the actual magnetic circuit and operating condition; the product name alone is not enough to select the part.
Start with ferrite grade and orientation relative to the working face. Then check the required magnetic output, geometry, temperature and commercial volume before fixing a grade in the drawing.
Control the dimensions that set fit, air gap or working position. For this product, review length, cross-section, flatness, edge condition and magnetization direction; avoid applying a tight general tolerance to non-functional surfaces without a measurement reason.
Specify the magnetization axis or pole pattern, pole count where applicable, and the acceptance method. A field value must also state the measurement location, fixture or air gap so supplier and buyer evaluate the same condition.
Temperature capability depends on material grade, geometry, magnetizing state and the magnetic circuit. Provide temperature, impact risk, retention method and exposure medium; GX can then review demagnetization risk and whether the proposed material route fits the duty.
Use an agreed method tied to the application: material-property testing, surface field at a defined position, flux, pull force, pole pattern or waveform. The released drawing and acceptance plan should state the instrument, fixture and limits.
Send the drawing or 3D model, material or magnetic target, length, cross-section, flatness, edge condition and magnetization direction, temperature, impact risk, retention method and exposure medium, expected quantity and acceptance method. State whether tooling, inserts, assembly or magnetization is included in the requested supply scope.
Agree the drawing revision, tooling state, critical dimensions and magnetic test method before sample release. Approval should identify the sample record and any deviations; recurring orders then follow the released specification, quotation and control plan.
Project inquiry
Attach the part and assembly drawings. GX reviews bar geometry, material or magnetic target, magnetization, application conditions and inspection method before defining the sample route.
