From sintered blocks to straight slices and arc magnet segments. Compare the SOM-220D and SOM4-750D by part geometry, workpiece size and the finishing route your production needs.
NdFeB · Material-specific sample validation · Batch production
NdFeB slice samples — assess edge condition, cut surfaces and finishing allowance on your own material.
01 / The machining route
Where does cutting fit in your magnet production line?
Slicing creates the blank. Grinding, lapping and the downstream process establish the finished part. Plan the cutting allowance and acceptance requirements together.
01 / INPUT
Prepare the block
Grade, orientation, dimensions and holding surface.
02 / CUT
Slice or segment
Straight slices or arc geometry with the agreed fixture.
03 / CHECK
Inspect the blank
Thickness, edge condition and finishing allowance.
04 / FINISH
Grind & lap
Final thickness, flatness or curved surface geometry.
05 / NEXT
Clean & process
Continue to the specified coating or assembly route.
Illustration of output shapes. Exact arc geometry and the finishing route require a part-drawing review.
For straight slices, a multi-wire web makes parallel cuts through a workpiece. The roller-groove arrangement is selected for the target cut spacing; the resulting slice thickness also depends on the actual kerf. Wire diameter alone is not a guaranteed kerf measurement.
For arc or tile magnets, send the inner and outer radii, arc length, thickness and tolerance requirements. The SOM4-750D specification includes both straight-slice and arc-segment processing. That capability does not establish that every curved drawing can be finished in one cutting operation: the fixture, arc requirements and any subsequent grinding must be reviewed for the part.
Keep cutting and finishing requirements separate. A cut blank may still require grinding, lapping or edge work. Define what must be achieved directly by the saw and what will be achieved by the next operation before comparing quotations.
03 / Choose your equipment
SOM-220D and SOM4-750D: matching the machine to the part
Straight-slice productionSOM-220D
For smaller magnet blocks and straight slices within the specified thickness range.
These two models cover different magnet-production requirements. The figures above are from the respective model specifications. They are machine-capacity limits, not a guarantee of yield, surface finish or cycle time on a particular NdFeB grade.
The SOM4-750D accepts a longer workpiece, but its specified width is smaller than the SOM-220D's. Compare all three dimensions, not the model number alone. Likewise, a sub-millimetre magnet-slice requirement is outside the listed thickness ranges of both models. It needs a separate equipment and sample-cut review.
For the broader equipment family, see the multi wire saw model guide. A general model listing should not replace a review of your actual magnet drawing.
04 / Material matters
How do NdFeB, SmCo and ferrite requirements differ?
Rare earth magnet cutting equipment is often discussed as one category, but NdFeB and SmCo should not be assigned the same cutting recipe without verification. Ferrite is a different material family again. Keep the material identification visible in the sample-cut request and in the production setup.
Material
Review during selection
Relevant next step
NdFeB
Grade, block orientation, edge integrity, material loss and the condition required before finishing or coating
Compare SOM-220D and SOM4-750D against the workpiece and drawing
SmCo
Fixture support and fracture behaviour on the actual grade; verify the process separately from an NdFeB trial
Do not transfer a feed rate, wire-life figure or rejection rate from one magnet family to another. The proposed wire, fixture and coolant arrangement should be reviewed for the supplied material. Follow the material supplier's safety information and the approved operating procedure for coolant, swarf handling and cleaning; a general equipment guide does not define those procedures.
05 / Define the job
What information is needed to select an NdFeB cutting machine?
Start with the part drawing and the block that will enter the machine. “Motor magnet” alone does not define a cutting requirement: straight rectangular slices, curved segments and small thin parts can need different fixtures and process routes. Give the supplier the following inputs:
Material: magnet family, grade, condition and whether the workpiece is already magnetized.
Incoming workpiece: length, width and height, orientation requirements, and the surfaces available for holding or bonding.
Target geometry: straight slice or arc segment, including the drawing of any curved profile.
Thickness and tolerances: distinguish the as-cut thickness from the finished thickness after grinding or lapping.
Production demand: required accepted parts per shift, batch size, product mix and expected changeovers.
Current problem: edge damage, thickness variation, material loss, slow changeover or a downstream finishing bottleneck.
A machine that accommodates the block is only the starting point. Fixture space, slice support and finishing allowance also need to fit the proposed route. Compare equipment using the same part and acceptance criteria, rather than a cutting-speed number taken from a different material.
For laboratory and pilot batches across different materials, compare the SOM200 small multi wire saw. Its listed capacity is 200 × 200 × 200 mm with a 0.3–12 mm slice range; magnet suitability and as-cut quality still require a material-specific sample review.
Match the magnet application to the drawing
EV motor magnets: identify straight or arc geometry, dimensional tolerances and the finishing operations before assembly.
Wind turbine magnets: compare the complete workpiece envelope, holding arrangement and required accepted output.
Robot and servo motor magnets: specify the small-part support, edge condition and dimensional consistency required by the drawing.
Medical and MRI magnet components: identify the material, inspection requirements and downstream process before selecting equipment.
06 / Validate the process
Trial-cut evaluation and process limits
Use a sample cut to test the proposed route before treating a catalogue specification as a production result. Agree the material, drawing and acceptance criteria first. Useful checks include achieved slice thickness, thickness variation, edge condition, measured kerf and the allowance remaining for finishing.
Compare cutting methods on the same drawing
A multi-wire magnet slicing machine makes parallel cuts through a blank. Assess it when the job calls for repeated slices at a defined spacing. For individual cuts, prototypes or a change of profile, compare a suitable single-wire configuration and its fixture requirements. Arc segments require a geometry-specific review; a parallel wire web alone does not establish contour capability.
When comparing diamond wire cutting with an inner-diameter saw, use the same magnet grade, blank dimensions and finished-part requirements. Measure actual kerf, edge condition, accepted output and finishing allowance. A result from a different material or slice thickness is not a production forecast for your part.
Plan output from accepted parts
Estimate production from accepted parts per cycle and complete cycle time. Include loading, holding or bonding, cutting, unloading, inspection and changeover. Two workstations provide capacity for two workpieces, but do not establish a guaranteed doubling of accepted output. Material, fixture preparation and the rest of the line still determine shift output.
Compare cost per accepted part
Include the magnet blank, wire consumption, coolant and filtration, fixture preparation, operator time, maintenance, rejected slices and downstream finishing. Divide the total batch cost by the number of parts that meet the agreed acceptance criteria. Record the trial conditions alongside the result so quotations can be compared on the same basis.
Investigate defects before increasing speed
Edge chipping or breakage: review part support, fixture loading, wire condition and the recorded cutting setup.
Surface staining or an unexpected finish: review coolant compatibility, delivery and the cleaning sequence with the responsible process team.
Output below plan: separate cutting time from loading, unloading, changeover and rejected parts before choosing a larger machine.
Change process settings through a controlled trial rather than adopting percentage adjustments from an unrelated material. Record the result and its conditions so the selected setup can be evaluated again on a subsequent batch.
07 / Common questions
Frequently asked questions
Does this guide cover all permanent magnet materials?
NdFeB is the main application covered here. NdFeB and SmCo are rare-earth magnets; ferrite belongs to a different material family. The material comparison above links to the separate SmCo and ferrite guides. An NdFeB test does not qualify the same machine setup for another material.
Which model should I consider for straight NdFeB slices?
Start with SOM-220D when the workpiece fits 220 × 220 × 150 mm per station and the specified 2–8 mm thickness range covers the job. Review SOM4-750D for its different workpiece envelope or when arc-segment cutting is also required. Confirm the fixture and sample result before final selection.
Can the same machine make straight slices and arc magnets?
The SOM4-750D specification includes both modes. Send the arc drawing for a review of geometry, workholding and finishing needs. Do not assume that a straight-slice setup also establishes the settings for an arc part.
Does a smaller wire diameter guarantee lower production cost?
No. Compare measured kerf, accepted yield, wire consumption, cycle time and finishing needs together. A change that saves material per cut can still be unsuitable if it increases breakage, downtime or finishing work.
Can I use the saw's thickness range as the finished-part tolerance?
No. Thickness range describes the nominal slices the equipment is specified to produce. It is not a flatness, parallelism or thickness-variation guarantee. Agree the as-cut and finished-part acceptance requirements separately.
From drawing to equipment selection
Send us your magnet geometry and target slice thickness
Share the material grade, block dimensions, straight or arc drawing, tolerances and required output. We will review the equipment route with you.
