Precision Machining Technologies
Magnet Machining
Technical Comparison and the Advantages of Endless Diamond Wire Cutting
Why Magnet Machining Is Important?
Magnetic materials—such as NdFeB, SmCo, ferrite, and soft-magnetic alloys—are produced through powder metallurgy or casting, both of which generate parts with dimensional tolerances and surface conditions that cannot meet final application requirements. Precision machining is therefore a critical stage in the production of functional magnetic components.
And magnets are known for their intrinsic hardness, brittleness, and sensitivity to thermal and mechanical stress. These characteristics impose strict requirements on machining methods, particularly when dimensional accuracy, edge integrity, and magnetic performance stability are essential.
How to do Magnet Machining?
1. Overview of the Magnetic Material Processing Chain
Although different magnetic materials have different production routes, the generalized manufacturing flow includes:
1.1 Front-End Processes
Powder preparation & pressing (dry pressing, isostatic pressing)
Sintering or cast solidification
Aging or heat stabilization
Initial shaping (rough blanks)
At this stage, components typically carry significant dimensional allowance to permit subsequent precision machining.
1.2 Precision Machining
This phase determines the final dimensional accuracy, surface integrity, micro-crack density, and material yield.
Mainstream processes include:
Blade slicing / dicing
EDM wire cutting
Reciprocating long-wire diamond cutting
Endless diamond wire cutting (closed-loop, high-speed, thin-kerf)
Grinding, lapping, and superfinishing
1.3 Post-Machining
Deburring / chamfer formation
Surface finishing (grinding, lapping)
Protective coatings (Ni, NiCuNi, epoxy, Parylene)
Magnetic stabilization or demagnetization
Comparison of Precision Machining Methods
Magnet machining solutions
Magnetic materials are difficult to machine due to high hardness, pronounced brittleness, and susceptibility to thermal demagnetization. The following is a comparative analysis of mainstream machining technologies.
Blade Cutting (Diamond Slicing Blade)
A, Common for ferrite and small NdFeB blocks
B, Tool rigidity is limited; blade thickness usually 0.3–0.5 mm
C, Generates lateral cutting force → risk of edge chipping
D, Heat accumulation increases risk of micro-cracks
2,Advantages
A, Equipment cost relatively low
B, Suitable for small-size or thin parts
3,Limitations
A, Kerf loss relatively large
B, Surface roughness requires additional grinding
C, Not suitable for large blocks or brittle SmCo
EDM Wire Cutting
A, Used for NdFeB, SmCo, soft magnetic steels
B, Cutting is thermal; heat-affected zones alter local magnetic behavior
C, Edge carbonization may require multiple post-operations
2, Advantages
A, High shape-complexity capability
B, Stable for thick and dense materials 3, Limitations
A, Heat input is unavoidable → risk of demagnetization
B, Cutting speed relatively slow
C, Kerf ≈ 0.25 mm, not optimal for material yield
D, Cannot be used for ferrite or other non-conductive magnetic ceramics
Traditional Reciprocating Diamond Wire Saw
A, Wire length >1000 m, reciprocating motion
B, Direction change introduces vibration and varying tension
C, Wire speed limited due to reversal characteristics
2,Advantages
A, Used for large blocks and long parts
B, Cutting cost per hour relatively low
3,Limitations
A, Wire marks visible on surface
B, Fixed slice size, lacking flexibility
C, The equipment has a complex structure and is difficult to operate.
D, High equipment costs
Endless Diamond Wire Saw
A, Short closed-loop wire, typically <10 m in length
B, Single-direction continuous motion without reversal
C, Stable wire tension (150–250 N) maintained throughout cutting
D, High allowable wire speed, commonly 70–84 m/s
2, Advantages
A, Low cutting force and minimal vibration, suitable for brittle magnetic materials
B, Smooth, low-damage surfaces with no reciprocating wire marks
C, Higher dimensional accuracy and consistency across batches
D, Cutting speed relatively slow
E, Reduced need for post-grinding due to improved surface integrity
3, Limitations
A, not suitable for very large block sizes
The difference of traditional Diamond Wire and Endless Diamond Wire
Why Choose Endless Diamond Wire Cutting For Magnet Machining
A Closed-Loop, High-Stability Precision Cutting Technology
The endless diamond wire is a short, closed-loop wire (typical length <10 m) running continuously in a single direction at high linear speed (up to 80 m/s). The system maintains constant tension (150–250 N), eliminating the vibration and direction reversal inherent in conventional long-wire systems.
This leads to several technical advantages:
3.1 Ultra-Thin Kerf and High Yield
Wire diameter down to 0.30 mm
Kerf width typically 0.35–0.45 mm
For high-value NdFeB and SmCo blocks, this translates directly into cost reduction.
3.2 Low Cutting Stress, Minimal Chipping
Magnetic ceramics (ferrite) and sintered rare-earth magnets are highly brittle.
Endless wire provides:
Uniform unidirectional motion
Controlled wire tension
Reduced lateral load
As a result:
Edge chipping is significantly reduced
Subsurface damage depth is smaller
Post-grinding allowance is reduced
3.3 Superior Surface Quality
The continuous wire motion produces:
Smooth, scratch-free surfaces
Improved flatness and parallelism
Reduced requirement for lapping or grinding
This is essential for precision magnetic components used in motors, sensors, and micromachined assemblies.
3.4 High Cutting Efficiency
Because there is no wire reversal:
Wire can reach much higher stable linear speed
Cutting speed rate increases
Endless wire systems typically demonstrate 2–4× higher efficiency than reciprocating systems in hard, brittle magnetic materials.
3.5 Greater Process Consistency
With constant tension and one-direction motion:
Dimensional stability is higher
Cut-to-cut variation is minimized
Batch consistency improves
This is critical for multi-segment magnet arrays where tolerance stack-up cannot be tolerated.
Where Endless Wire Fits in Magent Machining Workflow?
| Process Stage | Typical Method | Positioning of Endless Wire |
|---|---|---|
| Blank shaping | Pressing, sintering, casting | Not involved |
| Primary cutting / block segmentation | Blade, EDM, long-wire | Endless wire is most advantageous |
| Precision slicing | Blade dicing, EDM,long-wire | Endless wire offers flexiblity |
| Grinding & finishing | Surface grinding, lapping | Not involved |
| Coating / magnetizing | Ni plating, epoxy, magnetic alignment | Not involved |
Vimfun
Typical Application
Sintered NdFeB
High hardness + brittleness → blade cutting often causes chipping
EDM introduces thermal damage
Endless wire: optimal for slicing large blocks with minimum kerf
SmCo (Samarium–Cobalt)
Extremely brittle
Sensitive to thermal stress → EDM not suitable
Endless wire produces clean, low-stress cuts
Ferrite (MnZn / NiZn)
Ceramic-like structure, prone to edge fracture
Endless wire outperforms blade slicing with less vibration and chipping
Soft-Magnetic Alloy Cores
For laminated or precision machined cores
Endless wire enables high-precision segmentation without thermal alteration
Demonstration Videos of Magnet Machining
All Diamond Wire Saw Products
Endless diamond wire cutting machinery you can choose from
FAQ For Magnet Machining
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How do wire speed and tension affect surface quality?
*Higher wire speed improves grinding efficiency and reduces surface scratches, while stable tension (150–250 N) minimizes vibration. Low tension causes waviness and chatter marks; excessive tension increases risk of wire breakage.
Why is diamond wire cutting considered a low-stress and low-temperature process?
*The wire contacts the material along a narrow line, reducing frictional heat and limiting thermal expansion. Although some heat is generated, the temperature rise is minimal, preventing cracks or deformation in brittle materials such as sapphire or alumina.
what is your opening hours?
*Initial one-to-one consultation, Health & Fitness Assasments Bespoke training program planing, Custom Nutrition plan & recipes. Weekly Progress Reviews
What is the optimal wire speed for high-quality cutting?
*For most brittle crystalline materials, the optimal wire speed is 50–80 m/s. Higher speeds improve material removal efficiency but require stable tension and precise alignment of guide wheels.
What causes wire vibration, and how can it be avoided?
*Wire vibration is usually caused by incorrect tension, worn grooves, or improper wheel alignment. Maintaining stable tension, using intact guide grooves, and ensuring clean coolant flow significantly reduces vibration.
Why is diamond wire cutting preferred for high-value materials such as sapphire and semiconductor crystals?
*It offers:
Minimal subsurface damage
Low kerf loss (cost saving)
Smooth cutting surfaces
Consistent thickness across the entire cut
Cold and low-stress processing
This combination makes it ideal for expensive materials where yield and quality are critical.