The SR824 Low Noise EMQ Bearing is a miniature deep groove ball bearing engineered to Electric Motor Quality (EMQ) standards, specifically developed for applications where rotational silence, vibration control, and long-term reliability are non-negotiable. With a 0.5000-inch bore and 0.7500-inch outer diameter, this bearing fits into the most space-constrained assemblies while delivering the noise performance demanded by precision motors, medical handpieces, and high-end instrumentation.
Unlike standard miniature bearings that merely meet dimensional tolerances, the SR824 EMQ undergoes 100% sealing inspection before shipment to eliminate the risk of dust and debris ingress—a leading cause of long-term efficiency degradation. Every batch is evaluated using dedicated noise testers and vibration testers, classified according to Z1–Z4 noise levels and V1–V4 vibration levels, with the SR824 targeting the upper echelon of these scales.
Parameter Value
Bearing Designation SR824 (Low Noise EMQ Grade)
Bearing Type Miniature Deep Groove Ball Bearing, Single Row
Bore Diameter (d) 0.5000 in (12.700 mm)
Outer Diameter (D) 0.7500 in (19.050 mm)
Width (B) 0.1562 in (3.967 mm)
Measurement System Inch
Material (Rings & Balls) 440C Stainless Steel / GCr15 Bearing Steel (options available)
Cage Material Stainless Steel / Crown Steel
Dynamic Radial Load 207 lbf (920 N)
Static Radial Load 121 lbf (538 N)
Max Speed (Grease) 12,000 RPM
Radial Clearance C0 (0.003–0.018 mm)
ABEC Tolerance ABEC 3 / ABEC 5 (ABEC 7 available on request)
Noise Grade Z1–Z4 (application-specific selection)
Vibration Grade V1–V4 (application-specific selection)
Lubrication Lithium-based grease (closed type) / Antirust oil (open type)
Sealing Open / ZZ (metal shield) / 2RS (rubber seal)
Temperature Range −86°F to 230°F (−66°C to 110°C)
Weight 3.01 g
RoHS / REACH Compliant
The dimensional data above reflects the standard SR824 envelope. MTWB manufactures this bearing across a precision range from ABEC 3 to ABEC 7, allowing engineers to match tolerance class to application criticality.
Low Noise Architecture. The SR824 EMQ is built around a targeted quality-control protocol applied during inner ring raceway grinding—the single most influential manufacturing stage for noise reduction. Combined with honed and precision-ground raceways, this process eliminates the microscopic surface irregularities that generate high-frequency vibration and audible noise.
100% Seal Integrity Verification. Before any SR824 bearing leaves the production line, its sealing effectiveness is individually inspected. This step directly addresses the failure mode where inadequate sealing allows contaminants to enter the raceway, progressively degrading efficiency.
Dual-Stage Noise and Vibration Testing. Bearings are tested both before and after lubrication, ensuring that the grease itself does not introduce acoustic degradation. The Z1–Z4 noise classification and V1–V4 vibration classification give design engineers a quantifiable basis for selection rather than a subjective “quiet” claim.
Material Discipline. The SR824 is produced from G95Cr18 (440C stainless steel) or GCr15 (SAE 52100) chrome steel, with 300-series stainless steel available for corrosion-sensitive environments. These materials deliver the fatigue strength and wear resistance required for continuous high-speed operation.
For other miniature low-noise applications, see our
SR1232 Bearing
Precision Motors & Micro Drive Systems. The SR824 EMQ primary application domain is in small electric motors where bearing-generated noise propagates directly into the end product’s acoustic signature. Its EMQ grading makes it suitable for use in encoder-equipped servo motors, stepper motors for medical dosing pumps, and spindle motors in dental and surgical handpieces operating at speeds up to 80,000 RPM.
Medical Devices & Surgical Instruments. From powered surgical hand tools to laboratory automation equipment, the SR824 combination of stainless steel construction, low particle emission, and verified sealing performance suits environments where sterility and reliability are co-critical.
Precision Instruments & Robotics. The bearing ABEC 5 tolerance and C0 clearance support the repeatable positioning required in optical instruments, semiconductor handling equipment, and collaborative robot joints where backlash and vibration must be minimized.
Industrial Automation & Mechatronics. In compact gearboxes, linear actuator feedback systems, and vision inspection stages, the SR824 provides a vibration-stable rotational interface that preserves measurement accuracy.
A common misconception in bearing procurement is that any miniature bearing rated for “power tools” is automatically suitable for EMQ applications. The reality is more nuanced, and the differences are consequential.
1. Noise and Vibration Specification
Power hand tool bearings are typically selected against ABEC 1 tolerances with standard noise levels. Their design priority is ruggedness under intermittent high-load conditions, not acoustic precision. The SR824 EMQ, by contrast, is manufactured to ABEC 3 or higher and tested against the Z1–Z4 noise scale, with vibration checked at V1–V4 levels. A power tool bearing may pass a functional spin test; an EMQ bearing must pass a controlled acoustic evaluation.
2. Sealing Philosophy
Power tools often use shielded bearings (ZZ) where a metal shield tolerates debris exposure without the friction penalty of a contact seal. The trade-off is that shields allow fine particulate ingress over time. The SR824’s 100% seal inspection regime treats sealing integrity as a primary quality gate, not a secondary consideration. For applications where the bearing operates near sensitive optics, fluid lines, or sterile fields, this difference is decisive.
3. Lubrication and Lifecycle
Hand tool bearings are commonly lubricated once for the lifetime of the device, with grease selection driven primarily by operating temperature. EMQ bearings such as the SR824 are noise-tested after lubrication, meaning the grease itself is evaluated for acoustic contribution. MTWB specifies lithium-based grease for closed bearings but can substitute application-specific lubricants where required.
4. Speed and Preload Management
Power hand tool applications can reach 60,000 RPM and rely on axial preload to stabilize ball motion. EMQ bearings are designed for comparable or higher speeds, but with the additional constraint that preload-induced vibration must remain below the tested V-grade threshold. The SR824’s optimized raceway geometry supports uniform ball orbit without the acoustic penalty that preload sometimes introduces in standard-grade bearings.
Criterion Power Hand Tool Bearing SR824 Low Noise EMQ
Tolerance Class ABEC 1 (typical) ABEC 3–5 (standard)
Noise Testing Functional check Z1–Z4 classified
Vibration Testing Not typically specified V1–V4 classified
Seal Inspection Sampling basis 100% individual
Lubrication Evaluation Temperature-driven Pre- and post-lube noise tested
Primary Design Goal Durability, torque Acoustic precision, longevity
MTWB supports application-specific modification of the SR824 platform, including non-standard radial clearance, alternative cage materials, custom grease fill volumes, and hybrid ceramic ball configurations. The bearing is available in open, ZZ, and 2RS variants, with packaging options from individual blister packs to bulk industrial quantities.
For engineers transitioning from a power-tool-grade bearing to an EMQ solution, our technical team can provide noise-grade matching, preload recommendations, and sample testing against your specific operating profile.
MTWB miniature DGBB manufacturing platform covers bore diameters from 0.6 mm to 380 mm OD, with the SR824 representing the intersection of micro-scale precision and EMQ-grade acoustic control. The same grinding, honing, and testing disciplines that enable our sub-millimeter bearings are applied to every SR824 unit. The result is a bearing that does not merely fit the envelope—it preserves the performance of the system it serves.
What is an SR824 bearing?
The SR824 is an inch-series miniature deep groove ball bearing designed for low-noise and precision applications. It has a 1/2-inch bore, 3/4-inch outside diameter and 5/32-inch width.
What are the dimensions of an SR824 bearing?
The SR824 bearing measures 1/2 × 3/4 × 5/32 inch, equivalent to approximately 12.700 × 19.050 × 3.967 mm.
What material is available for SR824 bearings?
SR824 bearings can be manufactured with 440C stainless steel or GCr15 bearing steel, depending on corrosion resistance, load and application requirements.
What is an SR824 EMQ bearing used for?
SR824 EMQ bearings are suitable for precision motors, medical handpieces, surgical instruments, laboratory automation, robotics and other applications where controlled noise and vibration are important.
What sealing options are available for SR824?
The SR824 is available in open, ZZ shielded and 2RS sealed configurations, depending on the application and environmental requirements.
October 14,2026
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