NEMA 8 20 mm Rotary Stepper Motor
The Size 8 / 20 mm 2-phase hybrid rotary stepper motor provides compact rotary positioning with up to 0.02 N·m holding torque.
Encoder options, 22 mm planetary gearbox solutions, power-off brake options, and custom windings are available for OEM applications.
Parameters
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| General Specification | Value |
|---|---|
| Step Angle Accuracy | 1.8° ±5% |
| Resistance Accuracy | ±10% @ 20°C |
| Inductance Accuracy | ±20% @ 1 kHz |
| Insulation Class | B |
| Duty Type | S1 |
| Dielectric Strength | 500 VAC / 1 kHz / 1 mA / 1 s |
| Insulation Resistance | 100 MΩ / 500 VDC |
| Permissible Radial Load | 5 mm Distance | 10 mm Distance | 15 mm Distance | 20 mm Distance |
|---|---|---|---|---|
| Load from Mounting Surface | 15 N | 12 N | 8 N | 6 N |
| Type | Current A RMS | Resistance Ω | Inductance mH | Holding Torque N·m | Holding Torque oz-in | Rotor Inertia g·cm² | Length mm | Mass g |
|---|---|---|---|---|---|---|---|---|
| 8H2028 | 0.5 | 5.1 | 1.5 | 0.014 | 2.0 | 2.7 | 27 | 60 |
| 8H2038 | 0.5 | 8.8 | 2.7 | 0.02 | 2.8 | 3.3 | 38.2 | 80 |
| Material | Specification |
|---|---|
| End Bell | Aluminum Alloy |
| Bearing | Deep Groove Ball Bearing |
| Magnet | Sintered NdFeB |
| Shaft | Stainless Steel |
| Wiring | UL 3265, 28 AWG |
Dimensional Drawing
Torque Performance Curves
Available Options
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| Resolution CPR | 100 | 108 | 120 | 125 | 128 | 200 | 250 | 256 | 300 | 360 | 400 | 500 | 1000 | 512 | 720 | 800 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Single Ended Output | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| Differential Output | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P |
| House Material | Metal | |||||
|---|---|---|---|---|---|---|
| No Load Backlash | 1° | |||||
| Bearing | Sleeve Bearing | |||||
| Ratio | Rated Torque N·m | Limit Torque N·m | Stages | Efficiency % | Length mm | Mass g |
|---|---|---|---|---|---|---|
| 4 | 0.03 | 0.09 | 1 | 81 | 16.3 | 29.1 |
| 15 | 0.05 | 0.15 | 2 | 66 | 16.3 | 30.1 |
| 20 | ||||||
| 107 | 0.1 | 0.3 | 3 | 53 | 19.5 | 36 |
| Rated Voltage | DC 24V ± 5% |
|---|---|
| Resistance | 55Ω ± 10% |
| Power | 9.6W |
| Hold Torque | >0.06 N·m |
| Insulation | B |
| Insulation Resistance | >100MΩ DC500V |
| Dielectric Strength | AC 1000V for 1 sec |
| Retraction Time | 50ms |
| Release Time | 50ms |
| Gyration Gap | 1° |
| Emergency Brake Cycle | 200 cycles |
| Lifetime | 500,000 cycles |
| Noise Level | <60db |
Customizations
Mechanical
Mounting configurations, shaft configurations, end machining, NEMA size, length, bearings, lubricants, and dampers.
Electrical
Custom windings, insulation class, voltage and current ratings, cabling, connectors, and driver compatibility.
Feedback & Motion
Encoders, gearboxes, step angles, holding torque, speed targets, and application-specific motion profiles.
Environment
Clean room capable builds, application-specific durability, material review, and operating environment needs.
Downloads
08H2028-050-4AL
08H2028-050-4BL
08H2038-050-4AL
08H2038-050-4BL
Part Number Builder
08
Frame size / NEMA 8 motor platform.
H
Hybrid rotary stepper motor series.
20
Motor frame size in millimeters.
28 / 38
Motor body length. Available types include 8H2028 and 8H2038.
050
Rated current code, based on available motor winding.
4
Lead wire count.
A / B
Electrical connection or winding variation.
L
Lead wire version. Custom cabling and connectors are available.
Need help selecting or customizing a NEMA 8 rotary stepper motor?
DINGS’ Motion USA can help review holding torque, winding, shaft design, encoder requirements, gearbox integration, brake options, cabling, bearings, clean room needs, and custom mechanical features for your application.