Factory No.1 | Current Production Workshops
Our Vietnam facility operates a complete set of manufacturing workshops, covering the full process chain from cutting and grinding to assembly, magnetizing, testing, and surface treatment.
Advanced multi-wire cutting equipment for high-efficiency, high-tolerance slicing of large batches of magnetic material, minimizing raw material loss.
Suited for rapid prototyping and precision cutting of custom-shaped magnets and thin sheet material — non-contact, stress-free, with a minimal heat-affected zone.
Fully automatic double-side grinders and centerless grinders for extreme precision on surface roughness and flatness, achieving micron-level accuracy.
Precise chamfering and edge-rounding effectively prevents chipping at magnet corners, improves structural strength, and ensures uniform downstream plating.
Equipped with high-energy pulse magnetizers and automated assembly lines, offering a one-stop solution for magnetic assemblies from bonding through magnetizing.
Includes demagnetization curve testing, environmental reliability (PCT/HAST), and precision dimensional inspection, ensuring every batch meets international standards.
A precision machining area dedicated to production-process tooling and fixtures, supporting custom-shape machining, assembly, and quality stability to ensure mass-production consistency and on-site efficiency.
Five coating processes, selected by operating environment and reliability requirements, with standardized testing to ensure batch consistency.
Multi-Wire Cutting Workshop
High-throughput slicing for mass production
Multi-wire cutting is the core slicing process for NdFeB magnetic materials, using high-tension diamond wires to simultaneously cut large volumes of magnet blanks — balancing efficiency with dimensional precision and maximum raw material utilization.
- Core advantage: Runs 400–600 diamond wires simultaneously, cutting hundreds of slices per pass — suited for high-volume standard-spec magnet slices.
- Precision: Slice thickness consistency ±0.02 mm, kerf width < 0.2 mm, industry-leading raw material loss rate.
- Applicable range: Cylindrical and block magnet blanks ≥ 0.5 mm thick, supports simultaneous cutting of multiple sizes.
- Core function: Servo-controlled feed speed and cutting pressure with real-time compensation for cutting force variation, ensuring a flat cut surface.
- Precision metrics: Surface roughness Ra < 0.8 μm, flatness < 0.01 mm, minimal dimensional variation between batches.
- System advantage: Fully automatic tension compensation prevents diamond wire breakage, significantly reducing equipment downtime.
- Monitoring method: CCD cameras measure slice thickness in real time, automatically feeding back to adjust feed parameters.
- Quality assurance: Non-conforming pieces are removed immediately, ensuring a batch pass rate > 99.5%.
- Data traceability: Cutting data for every batch is automatically recorded, supporting quality traceability and process optimization analysis.
Why Choose Multi-Wire Cutting?
Compared to single-wire cutting, multi-wire cutting delivers production efficiency tens of times higher, with better raw material utilization at the same precision level. For customers needing high volume, tight tolerances, and stable lead times, the multi-wire cutting workshop is the process of choice.
Laser Cutting Workshop
The preferred choice for custom shapes and rapid prototyping
Laser cutting is suited for custom-shaped magnets, thin sheet material, and small-batch prototyping. It is non-contact with no mechanical stress and a minimal heat-affected zone, enabling high-precision machining of complex profiles.
- Output power: 500W–2kW, optimal cutting power selectable based on material thickness to reduce the heat-affected zone.
- Positioning accuracy: Servo-driven XY platform, positioning accuracy ±0.01 mm, repeatability ±0.005 mm.
- Cutting speed: Up to 5 m/min for thin sheets (< 1 mm), balancing efficiency and cut quality.
- Alignment principle: CCD cameras capture magnet position in real time, automatically comparing against CAD geometry to correct the cutting path.
- Application scenario: Custom-shaped magnets, parts with markings or feature edges — ensures consistent cutting position across every piece.
- Precision: Vision alignment error < 0.02 mm, substantially reducing manual alignment mistakes.
- Filtration performance: Three-stage filtration (HEPA + activated carbon), removing ≥ 99.97% of 0.3 μm particles.
- Safety compliance: Meets Vietnam factory emission standards, protecting operator health and the shop-floor environment.
- Real-time monitoring: Smoke concentration sensors automatically adjust extraction volume, ensuring continuous safety during cutting.
Why Choose Laser Cutting?
Traditional mechanical cutting leaves residual stress on the magnet surface, affecting magnetic performance and downstream processes. Laser cutting is entirely non-contact, especially suited for high-precision custom shapes, thin sheets, and projects requiring rapid prototyping — the cutting profile can be driven directly from CAD files, with prototype lead times as fast as 24 hours.
Grinding Workshop
Micron-level precision dimensional machining
The grinding workshop handles precision dimensional machining of magnetic materials via double-side grinding, centerless grinding, and surface grinding equipment, achieving micron-level flatness, parallelism, and roughness requirements — providing optimal input quality for downstream plating and magnetizing.
- Method: Magnet pieces are held in a planetary carrier while upper and lower grinding wheels grind both faces simultaneously, ensuring height consistency.
- Precision: Parallelism < 0.005 mm, flatness < 0.008 mm, surface roughness Ra ≤ 0.6 μm.
- Efficiency: Batch processing of tens to hundreds of pieces per run, far exceeding single-side grinding.
- Application: Precision outer-diameter machining for cylindrical and ring magnets, no chuck required, suited for high-volume production.
- Roundness precision: Roundness error < 0.003 mm, OD tolerance up to ±0.005 mm.
- Suitable products: Cylindrical and ring motor magnets, and components requiring precise OD fit.
- Mirror finishing: Achieves mirror-like Ra ≤ 0.4 μm, suited for magnets with optical or precision-fit requirements.
- Flatness: With precision worktables, flatness up to 0.003 mm, meeting the strictest assembly requirements.
- Applicable materials: Sintered NdFeB, SmCo and other rare-earth magnets, also suited for ferrite magnets.
Why Grinding Matters for Magnetic Performance
Grinding magnetic materials is not just dimensional machining — it directly affects downstream process quality. Precise flatness and parallelism ensure even plating adhesion, while good surface roughness improves magnetizing field coupling efficiency. Insufficient grinding precision is often a leading cause of non-conforming magnetic assemblies at the customer end.
Chamfering Workshop
Deburring & chamfering | Improving yield and plating performance
Chamfering is a critical process in volume magnet production: deburring, 45° chamfering, or R-corner treatment removes sharp edges, reduces chipping risk, and produces a more uniform downstream plating result. We match equipment and media combinations to product size, thickness, and target appearance to ensure batch consistency.
- Application: Gentler deburring/rounding, suited for chip-sensitive workpieces and larger/thicker parts.
- Process characteristics: Stable in batches, adjustable process window (media/time/condition), good appearance consistency.
- Recommended approach: Confirm appearance with samples before mass production to ensure long-term consistency.
- Application: Batch chamfering for small-to-medium parts, prioritizing efficiency and consistency.
- Process characteristics: Fast cycle time, uniform chamfering; can be tuned for gentle finishing or high-efficiency edge removal as needed.
- Lead time advantage: Suited for high-volume lead time and consistency requirements.
- Spherical media: General-purpose, suited for uniform deburring and smooth transitions; smaller sizes can be used on small parts to reduce chipping.
- Angled-cylinder media: Better for forming a stable R-corner effect, suited for products requiring rounded transitions and appearance consistency.
- Angled-triangle media: Better for forming a standard 45° chamfer, suited for products requiring a clearly defined angled profile.
How Do We Achieve Greater Stability?
We build a repeatable process window through "equipment + media matching + batch control": first confirming the target chamfer amount and appearance with samples, then locking in production parameters (load, time, media condition, cleaning) so every batch maintains the same edge condition.
Deliverables (Before & After Mass Production)
- Sample confirmation: confirm chamfering target (deburr / 45° / R-corner), appearance, and chipping risk.
- Media recommendations: based on size/thickness/shape, recommend spherical / angled-cylinder / angled-triangle media combinations.
- Production window: fixed load, time, media condition, and cleaning process to ensure batch consistency.
- Batch traceability: key parameters recorded per batch for retrospective analysis and continuous improvement.
Assembly & Magnetizing Workshop
One-stop integration for magnetic assemblies
The assembly & magnetizing workshop offers a one-stop integrated service for magnetic assemblies — from bonding and press-fitting to magnetizing — fully or semi-automated, ensuring magnetizing saturation and assembly precision meet customer specifications.
- Field strength: Instantaneous output field up to 4T, ensuring full magnetizing saturation for all NdFeB grades, including high-coercivity SH/UH/EH grades.
- Magnetizing methods: Supports axial, radial, and multi-pole (Halbach, interleaved multi-pole, etc.) magnetizing, with custom fixtures per customer drawings.
- Inline verification: Magnetic flux is measured immediately after magnetizing and compared against standard values, ensuring every part meets specification.
- Dispensing precision: Precision dispensing valves control adhesive volume to ±1 mg, ensuring consistent bond strength and avoiding overflow or insufficient adhesive.
- Assembly precision: Automated press-fit positioning fixtures achieve assembly position tolerance ±0.03 mm, suited for high-precision magnetic assemblies.
- Curing management: Constant-temperature curing ovens ensure full adhesive cure, with curing curve data provided for quality traceability.
- Method: Hall-effect sensors or fluxmeters measure flux value Φ piece-by-piece, compared against the customer's upper/lower spec limits.
- Screening efficiency: Fully automated sorting, non-conforming pieces removed automatically, inspection speed > 1,000 pieces/hour.
- Data recording: Every inspection result is automatically stored, supporting SPC analysis, batch traceability, and customer report generation.
Why Magnetize at the Manufacturing Stage?
Some customers choose unmagnetized blanks ("green magnets") to assemble themselves before magnetizing, but this requires expensive magnetizing equipment and strict operating protocols. With SINOWIN completing magnetizing at the manufacturing stage, customers receive finished magnetic assemblies directly, reducing their equipment investment while we take responsibility for magnetizing uniformity and consistency.
Testing Laboratory
The last line of defense for quality assurance
The testing laboratory is the last line of defense for quality assurance, covering magnetic performance, environmental reliability, and dimensional accuracy — ensuring every shipped batch meets customer specifications and international standards.
- Measurement parameters: Full BH hysteresis loop, measuring Br (remanence), Hcb (coercivity), Hcj (intrinsic coercivity), and (BH)max (maximum energy product).
- Temperature testing: Can be paired with a temperature-controlled chamber to measure magnetic property changes from -40°C to 200°C (Tc coefficient).
- Customer reports: Full BH curve report issued per batch, including Cpk statistical analysis, for customer product design validation.
- PCT testing: Pressure cooker test (121°C / 2atm / 100% RH), verifying coating corrosion resistance under extreme high temperature and humidity.
- Salt spray testing: Performed per ASTM B117 / ISO 9227 standards, verifying neutral salt spray corrosion resistance of coatings.
- HAST testing: Highly Accelerated Stress Test, simulating long-term in-use lifetime and reliability of magnetic parts.
- Measurement capability: High-precision 3D coordinate measurement with uncertainty < 1 μm, suited for full-dimensional inspection of complex-geometry magnets.
- Application range: Custom-shaped magnets, bore positions, arc surfaces, and other geometric features that manual gauges cannot effectively measure.
- Quality traceability: Measurement data is automatically output to the SPC system, forming traceable dimensional quality records.
Why Choose SINOWIN's Laboratory?
Many magnetic material suppliers offer only basic flux sampling. SINOWIN's laboratory provides full BH curve measurement, environmental reliability testing, and 3D dimensional verification — giving customer engineers direct access to sufficient design validation data, shortening new-product introduction cycles and reducing redesign risk from material spec mismatches.
Tooling & Fixture Workshop
Equipment Overview
Configured around NdFeB tooling machining needs. We chose to bring tooling fabrication in-house so that cost, lead time, and quality all remain within our control.
- Fast-speed WEDM: Core advantage is very high cutting efficiency and more competitive machining cost; used for general structural parts, large support blocks, and other auxiliary components with lower precision/roughness requirements.
- Medium-speed WEDM: Balances efficiency and geometric accuracy, with better surface finish and dimensional stability; used for magnet-slicing fixtures, precision positioning molds, and high-precision tooling, improving assembly tightness and yield.
- Selection recommendation: Flexibly combine fast-speed and medium-speed WEDM based on precision and lead-time needs, balancing cost and quality.
- Core function: Machines precision slots on the surface of feed rollers, improving drive friction and guiding stability.
- Machining advantage: Supports straight/spiral/grid slots (anti-slip texture), balancing cutting precision and production efficiency.
- Industry benefit: Reduces material slippage risk, strengthens automated conveying quality — a key piece of equipment for improving yield.
- Core function: Coats a resin/film layer, improving durability and cutting stability, reducing chipping and kerf loss.
- Technical features: High-precision tension control plus customizable design, ensuring efficient machining.
- Application value: For brittle magnetic materials, extends consumable life and improves finished-product yield.
Why Choose In-House Production?
In Vietnam, the tooling machining market commonly suffers from two pain points: a "capability gap" and "high costs." For projects requiring long-term stable mass production, we chose to bring tooling fabrication in-house so that cost, lead time, and quality all remain within our control.
Surface treatment workshop
NdFeB magnets are prone to oxidation; surface treatment determines their service life in real-world conditions. SINOWIN offers five coating processes, selected by operating environment, assembly method, and reliability requirements, with standardized testing to ensure batch consistency.
| Process | Characteristics | Salt spray test (SST) | Coating thickness |
|---|---|---|---|
| Ni-Cu-Ni | Ni-Cu-Ni · most common · metallic finish · wear-resistant | Up to >48h | 10–20μm |
| Epoxy | Epoxy spray · highest corrosion resistance · insulating · matte black | Up to 500h | 10–20μm |
| E-coating | Electrophoretic · uniform coverage · complex shapes · insulating | On request | Per spec |
| Cu-Ni-P | Cu-Ni-P · high hardness · corrosion-resistant · electroless | Up to 240h | 10–20μm |
| Zinc | Zinc · economical · suited to general environments | Up to >24h | 10–20μm |
Salt spray figures are achievable test values under specific conditions; actual acceptance criteria are confirmed per project specification. Standard coating thickness is 10–20μm, adjustable to custom requirements.
Quality inspection standards
- Adhesion：Cross-cut test
- Cleanliness：Dyne test
- Corrosion resistance：Neutral salt spray (NSS / ASTM B117)
Process Tolerance Overview
| Process | Tolerance / Accuracy |
|---|---|
| Multi-Wire Cutting | ±0.02mm / <0.2mm kerf |
| Double-Side Grinding | Parallelism <0.005mm, Flatness <0.008mm |
| Mirror Grinding | Ra ≤0.4μm, Flatness 0.003mm |
| Centerless Grinding (OD) | Roundness <0.003mm, OD ±0.005mm |
| Laser Cutting Positioning | ±0.01mm (repeat ±0.005mm) |
| CNC Precision Chamfering | ±0.02mm |
| Assembly Press-Fit | ±0.03mm |
| Dispensing | ±1mg |
| CMM Measurement | Uncertainty <1μm |