What is a magnetic rotary encoder magnet?

It is a precision multi-pole or diametrically magnetised ring/disc that provides a uniform magnetic field to a Hall/AMR sensor for accurate angular position measurement.

What accuracy can magnetic rotary encoders achieve?

With precision magnetised rings and tight concentricity, sub-degree angular accuracy is achievable; AIC tunes pole count, magnetisation, and runout to your encoder IC.

Can you supply matched magnet + sensor ring assemblies?

Yes. AIC supplies the magnetised ring to match your encoder IC, with optional mounting hub and concentricity verification, for motor feedback and servo applications.

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Magnetic Sensors

SKU: MS-PRE-012

Precision Rotary Encoder Magnet

Name: Precision Rotary Encoder Magnet
SKU: MS-PRE-012
Availability: InStock

精密磁性码盘

A precision rotary encoder disk is a special magnetic-scale product engineered for high-accuracy angular displacement measurement. Unlike a single-track linear scale, the disk carries multiple tracks (dual-track or multi-track), each encoded with its own pole pattern and read by a dedicated sensor head — enabling simultaneous measurement of multiple angles, redundant cross-checking, or absolute-plus-incremental output on one disk.

AIC Engineering combines advanced magnetic encoding with signal-processing techniques to deliver high-precision rotary measurement. Multi-track disks support absolute zero-reference tracking alongside incremental high-resolution channels, eliminating the need for a separate homing routine and improving reliability in servo motors, robotics joints, CNC rotary tables, and aerospace control surfaces.

Because reading is magnetic, the disk is immune to oil mist, dust, and chips that defeat optical encoder wheels — a decisive advantage in machine-tool and industrial environments. Disk diameter, track count, pole count per track, and material are tuned per application to meet the required angular resolution, operating temperature, and mechanical envelope.

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Key Features

Multi-Track Encoding

Dual- or multi-track disks — absolute reference + incremental high-resolution, or redundant cross-checking, on one disk.

No Homing Required

Absolute track provides true zero-reference — no power-on homing routine, faster startup for servo and robotics.

Immune to Contamination

Magnetic reading defeats oil mist, dust, and chips that blind optical encoder wheels — reliable in machine tools.

Customised per Application

Disk diameter, track count, pole count, and material tuned to your angular resolution and temperature requirement.

Track & Encoding Options

Configurable per application — send your angular resolution, mechanical envelope, and output protocol.

Configuration	Description	Typical Use
Single-Track Incremental	One track with periodic pole pattern; quadrature output.	Simple speed / direction sensing, motor commutation.
Dual-Track (Absolute + Incremental)	Absolute reference track + high-resolution incremental track.	True zero-reference with high resolution, no homing.
Multi-Track Redundant	Multiple tracks cross-read for redundancy.	Safety-critical aerospace, robotics, medical — fault tolerance.
Multi-Pole High-Resolution	High pole count per track for fine angular steps.	Servo motors, CNC rotary tables, precision gimbals.
Ring / Disc Geometry	Disc or ring form to fit shaft or hollow-shaft mounting.	Robotics joints, hollow-shaft servos, direct-drive tables.
Material Selection	NdFeB (high field) / SmCo (high temp) / bonded (complex shape).	Match field strength, temperature, and geometry to the design.

Standard Dual-Track Disc Range

21 standard axially-magnetised dual-track disc models in three pole-pitch series — MU128 (≈1.28 mm), MU150 (≈1.5 mm) and MU200 (≈2.0 mm). The main track carries the incremental signal; the vernier track has one pole pair fewer, enabling single-turn absolute angle via the Nonius principle. Custom shaft sizes and mountings available on request.

Model (Order Code)	Pole Pairs (Main / Vernier)	Shaft Ø (mm)	Carrier OD (mm)	Height (mm)	Carrier Material	Mounting
MU128 Series · pole pitch ≈ 1.28 mm
MU128-15-29-1.1 (22H097)	32 / 31	15 (H7)	29	1.1	SUS430 stainless steel	Press-fit
MU128 SMD35-55-2.5 (21H095)	64 / 63	35 (H7)	55	2.5	SUS430 stainless steel	Press-fit
MU128-35-56-2 (22H092)	64 / 63	35 (H7)	56	2	SUS430 stainless steel	Press-fit
MU128 SMD37-56-12.6 (21H018)	64 / 63	37 (H7)	56	13	Aluminium alloy	Press-fit
MU150 Series · pole pitch ≈ 1.5 mm
MU150 SMD19.5-31.5-2 (22H002)	32 / 31	19.5 (H7)	31.5	2.1	SUS430 stainless steel	Press-fit
MU150 SMD15-33.5-1.1 (22H055)	32 / 31	15 (H7)	33.5	1.1	SUS430 stainless steel	Press-fit
MU150-20-33-2 (23H037)	32 / 31	20 (H7)	33	2	SUS430 stainless steel	Press-fit
MU150-23-35-2 (22H113)	32 / 31	23 (H7)	35	2	SUS430 stainless steel	Press-fit
MU150 SMD18.5-34-8 (22H041)	32 / 31	20.5 (H7)	34	8	SUS430 stainless steel	Press-fit
MU150 SMD20-34-11 (21H017)	32 / 31	20 (H7)	34	11.5	Aluminium alloy	Press-fit
MU150 SMD18-34-5 (21H032)	32 / 31	18 (H7)	34	5.2	Aluminium alloy	Press-fit
MU150 SMD20-33.5-8.7 (22H054)	32 / 31	M20	33.5	8.7	SUS430 stainless steel	Threaded
MU150-14-34-2.2 (22H082)	32 / 31	14 (H7)	34	6.2	Aluminium alloy	Press-fit
MU150-17-34-7.2 (22H083)	32 / 31	17 (H7)	34	7.2	Aluminium alloy	Press-fit
MU150 SMD45-64-5 (22H050)	64 / 63	45 (H7)	64	5	Aluminium alloy	Press-fit
MU150-44-64-7.5 (23H002)	64 / 63	44 (H7)	64	7.5	Aluminium alloy	Press-fit
MU200 Series · pole pitch ≈ 2.0 mm
MU200 SMD25-44.5-1.4 (22H006)	32 / 31	25 (H7)	44.5	1.4	SUS430 stainless steel	Press-fit
MU200 SMD25-49-2 (21H110)	32 / 31	25 (H7)	49	2	SUS430 stainless steel	Press-fit
MU200-25-49-2 (23H003)	32 / 31	25 (H7)	49	2	SUS430 stainless steel	Press-fit
MU200-35-48-2 (23H038)	32 / 31	35 (H7)	48	2	SUS430 stainless steel	Press-fit
MU200 SMD42-52-5.5 (22H053)	32 / 31	42	52	5.5	SUS430 stainless steel	Threaded

Full Model Specifications

Technical drawing, factory Nonius-calibration test data, and the complete dimensional parameter table for every standard model. Click a row to expand.

MU128 Series · pole pitch ≈ 1.28 mm

MU128-15-29-1.1(22H097)32 / 31 polesØ 15 (H7)29 × 1.1 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 29 mm, shaft Ø 15 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU128-15-29-1.1 Technical Drawing — Technical Drawing

MU128-15-29-1.1 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	11.24	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	1.1	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	18.88	—	mm
B2	Main Track Diameter	Main track detection diameter	26.08	—	mm
B3	Magnetic Material OD	—	29	—	mm
B4	Magnetic Material ID	—	16	—	mm
B5	Bore Diameter	Carrier	15	H7	mm
B6	Diameter	Carrier	29	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.28	—	mm
M2	Main Track Pole Width	At main track detection diameter	0.96	—	mm

MU128 SMD35-55-2.5(21H095)64 / 63 polesØ 35 (H7)55 × 2.5 mm

Dual-track axially-magnetised encoder disc: main track 64 pole pairs, vernier track 63 pole pairs; carrier OD 55 mm, shaft Ø 35 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU128 SMD35-55-2.5 Technical Drawing — Technical Drawing

MU128 SMD35-55-2.5 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	24.28	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2.5	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	44.95	—	mm
B2	Main Track Diameter	Main track detection diameter	52.15	—	mm
B3	Magnetic Material OD	—	55	—	mm
B4	Magnetic Material ID	—	42	—	mm
B5	Bore Diameter	Carrier	35	H7	mm
B6	Diameter	Carrier	55	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.12	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.28	—	mm
N1	Mounting Holes	Qty 8, evenly spaced	Φ2.2	—	mm

MU128-35-56-2(22H092)64 / 63 polesØ 35 (H7)56 × 2 mm

Dual-track axially-magnetised encoder disc: main track 64 pole pairs, vernier track 63 pole pairs; carrier OD 56 mm, shaft Ø 35 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU128-35-56-2 Technical Drawing — Technical Drawing

MU128-35-56-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	24.28	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	—	mm
B1	Vernier Track Diameter	Vernier track detection diameter	44.95	—	mm
B2	Main Track Diameter	Main track detection diameter	52.15	—	mm
B3	Magnetic Material OD	—	55.5	—	mm
B4	Magnetic Material ID	—	41.2	—	mm
B5	Bore Diameter	Carrier	35	H7	mm
B6	Diameter	Carrier	56	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.12	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.28	—	mm

MU128 SMD37-56-12.6(21H018)64 / 63 polesØ 37 (H7)56 × 13 mm

Dual-track axially-magnetised encoder disc: main track 64 pole pairs, vernier track 63 pole pairs; carrier OD 56 mm, shaft Ø 37 (H7) (Press-fit); carrier material: Aluminium alloy.

MU128 SMD37-56-12.6 Technical Drawing — Technical Drawing

MU128 SMD37-56-12.6 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	24.28	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	13	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	44.95	—	mm
B2	Main Track Diameter	Main track detection diameter	52.15	—	mm
B3	Magnetic Material OD	—	55	—	mm
B4	Magnetic Material ID	—	41.2	—	mm
B5	Bore Diameter	Carrier	37	H7	mm
B6	Shaft Diameter	Carrier	45	—	mm
B7	Diameter	Carrier	56	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.12	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.28	—	mm
N1	Tapped Holes	Qty 3	M2	—	—

MU150 Series · pole pitch ≈ 1.5 mm

MU150 SMD19.5-31.5-2(22H002)32 / 31 polesØ 19.5 (H7)31.5 × 2.1 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 31.5 mm, shaft Ø 19.5 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU150 SMD19.5-31.5-2 Technical Drawing — Technical Drawing

MU150 SMD19.5-31.5-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2.1	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	22.4	—	mm
B2	Main Track Diameter	Main track detection diameter	29.6	—	mm
B3	Magnetic Material OD	—	31.5	—	mm
B4	Magnetic Material ID	—	20.5	—	mm
B5	Bore Diameter	Carrier	19.5	H7	mm
B6	Diameter	Carrier	31.5	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.13	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.45	—	mm

MU150 SMD15-33.5-1.1(22H055)32 / 31 polesØ 15 (H7)33.5 × 1.1 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 33.5 mm, shaft Ø 15 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU150 SMD15-33.5-1.1 Technical Drawing — Technical Drawing

MU150 SMD15-33.5-1.1 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	1.1	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	33	—	mm
B4	Magnetic Material ID	—	21.5	—	mm
B5	Bore Diameter	Carrier	15	H7	mm
B6	Diameter	Carrier	33.5	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150-20-33-2(23H037)32 / 31 polesØ 20 (H7)33 × 2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 33 mm, shaft Ø 20 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU150-20-33-2 Technical Drawing — Technical Drawing

MU150-20-33-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	33	—	mm
B4	Magnetic Material ID	—	20.4	—	mm
B5	Bore Diameter	Carrier	20	H7	mm
B6	Diameter	Carrier	33	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150-23-35-2(22H113)32 / 31 polesØ 23 (H7)35 × 2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 35 mm, shaft Ø 23 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU150-23-35-2 Technical Drawing — Technical Drawing

MU150-23-35-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	14.75	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	25.9	—	mm
B2	Main Track Diameter	Main track detection diameter	33.1	—	mm
B3	Magnetic Material OD	—	35	—	mm
B4	Magnetic Material ID	—	24	—	mm
B5	Bore Diameter	Carrier	23	H7	mm
B6	Diameter	Carrier	35	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.31	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.62	—	mm

MU150 SMD18.5-34-8(22H041)32 / 31 polesØ 20.5 (H7)34 × 8 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 34 mm, shaft Ø 20.5 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU150 SMD18.5-34-8 Technical Drawing — Technical Drawing

MU150 SMD18.5-34-8 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	8	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	34	—	mm
B4	Magnetic Material ID	—	20.4	—	mm
B5	Bore Diameter	Carrier	20.5	H7	mm
B6	Shaft Diameter	Carrier	22.5	—	mm
B7	Diameter	Carrier	34	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150 SMD20-34-11(21H017)32 / 31 polesØ 20 (H7)34 × 11.5 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 34 mm, shaft Ø 20 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150 SMD20-34-11 Technical Drawing — Technical Drawing

MU150 SMD20-34-11 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	11.5	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	33	—	mm
B4	Magnetic Material ID	—	20.4	—	mm
B5	Bore Diameter	Carrier	20	H7	mm
B6	Shaft Diameter	Carrier	25	—	mm
B7	Diameter	Carrier	34	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm
N1	Tapped Holes	3, evenly spaced	M2	—	—

MU150 SMD18-34-5(21H032)32 / 31 polesØ 18 (H7)34 × 5.2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 34 mm, shaft Ø 18 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150 SMD18-34-5 Technical Drawing — Technical Drawing

MU150 SMD18-34-5 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	5.2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	34	—	mm
B4	Magnetic Material ID	—	20	—	mm
B5	Bore Diameter	Carrier	18	H7	mm
B6	Shaft Diameter	Carrier	20	—	mm
B7	Diameter	Carrier	34	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150 SMD20-33.5-8.7(22H054)32 / 31 polesØ M2033.5 × 8.7 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 33.5 mm, shaft Ø M20 (Threaded); carrier material: SUS430 stainless steel.

MU150 SMD20-33.5-8.7 Technical Drawing — Technical Drawing

MU150 SMD20-33.5-8.7 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	8.7	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	33	—	mm
B4	Magnetic Material ID	—	21.3	—	mm
B5	Threaded Bore Diameter	Carrier	M20	—	—
B6	Shaft Diameter	Carrier	24.7	—	mm
B7	Diameter	Carrier	33.5	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150-14-34-2.2(22H082)32 / 31 polesØ 14 (H7)34 × 6.2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 34 mm, shaft Ø 14 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150-14-34-2.2 Technical Drawing — Technical Drawing

MU150-14-34-2.2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	6.2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	34	—	mm
B4	Magnetic Material ID	—	20.4	—	mm
B5	Bore Diameter	Carrier	14	H7	mm
B6	Shaft Diameter	Carrier	20	—	mm
B7	Diameter	Carrier	34	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150-17-34-7.2(22H083)32 / 31 polesØ 17 (H7)34 × 7.2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 34 mm, shaft Ø 17 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150-17-34-7.2 Technical Drawing — Technical Drawing

MU150-17-34-7.2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	13.48	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	7.2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	23.36	—	mm
B2	Main Track Diameter	Main track detection diameter	30.56	—	mm
B3	Magnetic Material OD	—	34	—	mm
B4	Magnetic Material ID	—	20.4	—	mm
B5	Bore Diameter	Carrier	17	H7	mm
B6	Shaft Diameter	Carrier	22	h7	mm
B7	Diameter	Carrier	34	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.18	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150 SMD45-64-5(22H050)64 / 63 polesØ 45 (H7)64 × 5 mm

Dual-track axially-magnetised encoder disc: main track 64 pole pairs, vernier track 63 pole pairs; carrier OD 64 mm, shaft Ø 45 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150 SMD45-64-5 Technical Drawing — Technical Drawing

MU150 SMD45-64-5 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	28.76	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	5	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	53.92	—	mm
B2	Main Track Diameter	Main track detection diameter	61.11	—	mm
B3	Magnetic Material OD	—	64	—	mm
B4	Magnetic Material ID	—	51	—	mm
B5	Bore Diameter	Carrier	45	H7	mm
B6	Shaft Diameter	Carrier	64	h7	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.34	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU150-44-64-7.5(23H002)64 / 63 polesØ 44 (H7)64 × 7.5 mm

Dual-track axially-magnetised encoder disc: main track 64 pole pairs, vernier track 63 pole pairs; carrier OD 64 mm, shaft Ø 44 (H7) (Press-fit); carrier material: Aluminium alloy.

MU150-44-64-7.5 Technical Drawing — Technical Drawing

MU150-44-64-7.5 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	28.76	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	7.5	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	53.92	—	mm
B2	Main Track Diameter	Main track detection diameter	61.11	—	mm
B3	Magnetic Material OD	—	64	—	mm
B4	Magnetic Material ID	—	50	—	mm
B5	Bore Diameter	Carrier	44	H7	mm
B6	Shaft Diameter	Carrier	52	—	mm
B7	Diameter	Carrier	64	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.34	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.5	—	mm

MU200 Series · pole pitch ≈ 2.0 mm

MU200 SMD25-44.5-1.4(22H006)32 / 31 polesØ 25 (H7)44.5 × 1.4 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 44.5 mm, shaft Ø 25 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU200 SMD25-44.5-1.4 Technical Drawing — Technical Drawing

MU200 SMD25-44.5-1.4 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	18.37	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	1.4	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	32.74	—	mm
B2	Main Track Diameter	Main track detection diameter	40.74	—	mm
B3	Magnetic Material OD	—	44	—	mm
B4	Magnetic Material ID	—	29	—	mm
B5	Bore Diameter	Carrier	25	H7	mm
B6	Diameter	Carrier	44.5	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	2	—	mm
M2	Main Track Pole Width	At main track detection diameter	1.66	—	mm

MU200 SMD25-49-2(21H110)32 / 31 polesØ 25 (H7)49 × 2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 49 mm, shaft Ø 25 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU200 SMD25-49-2 Technical Drawing — Technical Drawing

MU200 SMD25-49-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	20.45	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	36.9	—	mm
B2	Main Track Diameter	Main track detection diameter	44.9	—	mm
B3	Magnetic Material OD	—	49	—	mm
B4	Magnetic Material ID	—	32.8	—	mm
B5	Bore Diameter	Carrier	25	H7	mm
B6	Diameter	Carrier	49	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.87	—	mm
M2	Main Track Pole Width	At main track detection diameter	2.2	—	mm

MU200-25-49-2(23H003)32 / 31 polesØ 25 (H7)49 × 2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 49 mm, shaft Ø 25 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU200-25-49-2 Technical Drawing — Technical Drawing

MU200-25-49-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	20.45	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	36.9	—	mm
B2	Main Track Diameter	Main track detection diameter	44.9	—	mm
B3	Magnetic Material OD	—	49	—	mm
B4	Magnetic Material ID	—	32.8	—	mm
B5	Bore Diameter	Carrier	25	H7	mm
B6	Diameter	Carrier	49	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.87	—	mm
M2	Main Track Pole Width	At main track detection diameter	2.2	—	mm

MU200-35-48-2(23H038)32 / 31 polesØ 35 (H7)48 × 2 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 48 mm, shaft Ø 35 (H7) (Press-fit); carrier material: SUS430 stainless steel.

MU200-35-48-2 Technical Drawing — Technical Drawing

MU200-35-48-2 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	20.85	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	2	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	37.7	—	mm
B2	Main Track Diameter	Main track detection diameter	45.7	—	mm
B3	Magnetic Material OD	—	48	—	mm
B4	Magnetic Material ID	—	35.4	—	mm
B5	Bore Diameter	Carrier	35	H7	mm
B6	Diameter	Carrier	48	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.91	—	mm
M2	Main Track Pole Width	At main track detection diameter	2.24	—	mm

MU200 SMD42-52-5.5(22H053)32 / 31 polesØ 4252 × 5.5 mm

Dual-track axially-magnetised encoder disc: main track 32 pole pairs, vernier track 31 pole pairs; carrier OD 52 mm, shaft Ø 42 (Threaded); carrier material: SUS430 stainless steel.

MU200 SMD42-52-5.5 Technical Drawing — Technical Drawing

MU200 SMD42-52-5.5 Factory Test Data — iC-MU Evaluation Software (Nonius Calibration) — Factory Test Data — iC-MU Evaluation Software (Nonius Calibration)

Code	Parameter	Note	Size	Tolerance	Unit
A1	Chip Center Radial Position	Distance from shaft center	20.45	—	mm
A2	Detection Air Gap	Gap between magnet and chip surface	0.4	—	mm
A3	Total Height	Product	5.5	+0.03	mm
B1	Vernier Track Diameter	Vernier track detection diameter	36.9	—	mm
B2	Main Track Diameter	Main track detection diameter	44.9	—	mm
B3	Magnetic Material OD	—	48	—	mm
B4	Magnetic Material ID	—	34	—	mm
B5	Bore Diameter	Carrier	42	—	mm
B6	Shaft Diameter	Carrier	45	—	mm
B7	Diameter	Carrier	52	—	mm
M1	Vernier Track Pole Width	At vernier track detection diameter	1.87	—	mm
M2	Main Track Pole Width	At main track detection diameter	2.2	—	mm

Bonded NdFeB Incremental Discs (AB + Z)

Multipole bonded-NdFeB encoder rings with an incremental AB track and a Z index track, assembled on SUS304 stainless-steel hubs. Eight standard sizes from Φ39 to Φ207 mm.

OD (mm)	ID (mm)	Height (mm)	Poles	AB-Track Field (GS)	Z-Track Field (GS)
Φ39.2 (±0.02)	Φ20 (+0.03/+0.01)	12 (±0.05)	64	600–800	325–825
Φ50.7 (−0.1)	Φ20 (+0.03/−0.01)	10 (±0.05)	82	315–452	325–825
Φ63.5 (−0.1)	Φ40 (+0.03/−0.01)	10 (±0.05)	102	315–452	325–825
Φ77.4 (−0.1)	Φ60 (+0.03/−0.01)	10 (±0.05)	124	315–452	325–825
Φ101.6 (±0.03)	Φ82 (+0.03)	10 (±0.1)	162	600–800	500–700
Φ122.3 (±0.03)	Φ90 (+0.03)	10 (±0.1)	192	600–800	500–700
Φ152.6 (±0.03)	Φ125 (+0.03)	10 (±0.1)	242	600–800	500–700
Φ206.7 (+0.1)	Φ160 (+0.05)	10 (±0.1)	326	315–452	325–825

Hub material: SUS304 stainless steel. Surface-field values are per-track factory inspection ranges; dimensional tolerances per drawing.

Magnetic Properties & Operating Conditions

Characteristics of the MU-series dual-track discs. NdFeB incremental discs are inspected against the surface-field ranges listed above.

170 kA/m

Coercivity (Hc)

at 20 °C

20 mT

Surface Field (Br)

at 20 °C

3 mT

Field Amplitude

at 0.4 mm air gap

0.4 mm

Detection Air Gap

magnet to chip surface

−35 … +120 °C

Operating Temperature

External Field Interference

External magnetic fields alter the disc's performance: fields ≥ 1 mT reduce system accuracy, and fields ≥ 20 mT can permanently damage the disc magnetisation. Avoid direct contact with magnetic clamps or other permanent magnets.

Disk Manufacturing

Magnetic ring or disc body with encoded multi-track pole pattern, precision-ground to concentricity, and paired with sensor-head specification.

1Disk Body

Material selection (NdFeB / SmCo / bonded)
Sintering or bonding to disc / ring shape
Precision grinding to concentricity ±0.02 mm
Surface coating for environmental protection

2Multi-Track Encoding

Fixture design for track layout
Pulse magnetising each track to its pole pattern
Per-track field distribution measurement
Absolute-reference index verification

3QC & Pairing

Concentricity & runout inspection
Angular-accuracy sampling per track
Sensor-head interface specification
Protective packaging for assembly

Typical Applications

Servo Motor FeedbackRobotics Joint EncodersCNC Rotary TablesAerospace Control SurfacesDirect-Drive Rotary StagesMedical Imaging GimbalsHollow-Shaft EncodersSafety-Critical Redundant Position Sensing

Need a Custom Precision Rotary Encoder Disk?

Send your angular resolution, mechanical envelope (shaft / hollow-shaft), operating temperature, and output protocol — our engineers will design the track layout, pole count, material, and sensor-head pairing.

Discuss Custom Requirements

Frequently Asked Questions

Answers to common questions about our magnets, customisation, ordering and shipping.

What is a magnetic rotary encoder magnet?: It is a precision multi-pole or diametrically magnetised ring/disc that provides a uniform magnetic field to a Hall/AMR sensor for accurate angular position measurement.
What accuracy can magnetic rotary encoders achieve?: With precision magnetised rings and tight concentricity, sub-degree angular accuracy is achievable; AIC tunes pole count, magnetisation, and runout to your encoder IC.
Can you supply matched magnet + sensor ring assemblies?: Yes. AIC supplies the magnetised ring to match your encoder IC, with optional mounting hub and concentricity verification, for motor feedback and servo applications.