SR620 Low Noise EMQ Bearing — Premium Electric Motor Quality Deep Groove Ball Bearing

The SR620 Low Noise EMQ Bearing is a precision-manufactured, single-row deep groove ball bearing engineered to Electric Motor Quality (EMQ) standards, delivering exceptionally quiet operation, minimal vibration, and long service life in high-speed rotating equipment. Manufactured from premium GCr15 bearing steel with optimized raceway geometry and 100% noise-tested quality control, the SR620 is the ideal bearing solution for electric motors, precision instruments, medical devices, and other applications where acoustic performance and rotational accuracy are critical.

The “EMQ” designation signifies that this bearing meets or exceeds the stringent requirements for electric motor quality — a standard that demands superior surface finish, tighter dimensional tolerances, and verified low-noise performance that ordinary commercial-grade bearings cannot match.

Key Specifications

Note: The SR620 is an inch-series bearing (SR = inch-dimensioned single-row). Custom dimensions, coatings, and lubricants are available upon request. Please confirm exact tolerances and clearance class for your specific application.

Product Features & Technical Advantages

1. Electric Motor Quality (EMQ) Construction

The SR620 EMQ bearing is built to the rigorous standards that define Electric Motor Quality. Unlike general-purpose bearings, EMQ bearings are specifically engineered to minimize noise and vibration at the source — through superior raceway honing, tighter ball grade classification, and optimized internal geometry. All EMQ bearings are noise tested before and after lubrication to ensure consistent acoustic performance in every unit.

2. Superior Raceway Finishing for Low Noise

Bearing noise is fundamentally a function of vibration, and vibration originates from surface irregularities on the raceways and balls. The SR620 undergoes precision grinding and superfinishing of the inner and outer ring raceways, achieving surface finishes that significantly reduce friction-induced vibration. This targeted quality control during the grinding process plays a decisive role in lowering overall bearing noise output.

3. 100% Inspection & Multi-Stage Quality Control

Every SR620 EMQ bearing undergoes:

●100% noise testing using dedicated noise testers and vibration testers, with noise levels classified under the Z1–Z4 grading system and vibration under V1–V4
●100% sealing effect inspection before shipment, preventing dust and debris ingress that could degrade long-term performance
●Full dimensional verification to ensure interchangeability and fit accuracy

This rigorous testing regime guarantees that every batch meets the criteria for low noise and high operational efficiency.

4. Premium Bearing Steel for Durability

The SR620 is manufactured from GCr15 (AISI 52100) high-carbon chrome bearing steel — the industry standard for demanding bearing applications. This material, combined with optimized heat treatment, delivers high hardness, excellent wear resistance, and dimensional stability over extended service life. For corrosion-sensitive environments, 300-series stainless steel construction is optionally available.

5. Optimized Lubrication for Acoustic Performance

Lubricant selection is a critical but often overlooked factor in bearing noise. The SR620 is available with:

●Antirust oil for open-type bearings where low torque is prioritized

●Lithium-based grease for shielded/sealed configurations, providing long-life lubrication with minimal noise contribution

Custom grease specifications can be accommodated to match specific temperature, speed, and load requirements.

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Application

The SR620 Low Noise EMQ Bearing is engineered for applications where quiet, smooth rotation is not merely desirable but essential to product performance and user experience:

Application Sector Typical Use Cases

Electric Motors Small AC/DC motors, stepper motors, servo motors, fan motors

Medical Devices Centrifuges, diagnostic equipment, micro-pumps, dental handpieces

Precision Instruments Optical encoders, analytical instruments, laboratory equipment

Robotics & Automation Joint actuators, linear guides, end-effectors, rotary tables

HVAC & Appliances Blower motors, circulation fans, compressor drives

Power Hand Tools Rotary tools, precision drills, engravers (see comparison below)

Audio & AV Equipment Turntable motors, tape transport mechanisms, camera pan-tilt heads

What Makes the SR620 EMQ Bearing a Unique Solution

Tailored for the Noise-Critical Application

The SR620’s inch-series dimensions (3/4″ × 1 5/8″ × 3/8″) make it a direct replacement for equipment originally designed around inch-standard bearings — a niche that metric EMQ bearings cannot fill without adapters or housing modification. This makes the SR620 particularly valuable in legacy equipment, imported machinery, and inch-system instrumentation where dimensional fidelity is non-negotiable.

Verified, Not Just Claimed, Quietness

Many bearing suppliers describe their products as “low noise” without providing verification. The SR620 EMQ bearing is backed by 100% acoustic inspection using calibrated noise and vibration testers. Customers receive documented noise grade classification (Z2 or Z3) and vibration grade (V2 or V3), providing objective evidence of performance rather than subjective assurance.

Application-Matched Lubrication

Rather than a one-size-fits-all grease fill, the SR620 EMQ offers application-matched lubrication: low-viscosity oil for minimum torque in instrument bearings, or long-life lithium grease for sealed configurations in motor applications. This granular approach to lubrication directly addresses the reality that grease is a major contributor to bearing noise, and the right lubricant can reduce noise by several decibels compared to a generic fill.

Scalable Precision Platform

The SR620 EMQ bearing serves as a platform that can be upgraded along multiple performance axes:

◆Noise grade: Z2 → Z3 → Z4

◆Vibration grade: V2 → V3 → V4

◆Precision class: ABEC 3 → ABEC 5 → ABEC 7

◆Material: GCr15 → Stainless steel → Ceramic hybrid

Each SR620 EMQ bearing shipment includes:

◆Certificate of Conformity (CoC) with dimensional and noise test data

◆Material certificates for GCr15 bearing steel

◆Lubrication specification and fill quantity

◆Recommended mounting and handling guidelines

FAQ

What is an SR620 bearing?

The SR620 is an inch-series single-row deep groove ball bearing designed for low-noise and precision applications. Its standard dimensions are 3/4 inch bore, 1-5/8 inch outside diameter and 3/8 inch width.

What are the dimensions of an SR620 bearing?

The SR620 bearing has a 3/4 inch bore, 1-5/8 inch outside diameter and 3/8 inch width.

What is an SR620 EMQ bearing used for?

SR620 EMQ bearings are suitable for small electric motors, medical devices, precision instruments, HVAC equipment, robotics and other applications requiring controlled noise and vibration.

What material is used for SR620 bearings?

The standard SR620 configuration uses GCr15 (AISI 52100) chrome bearing steel for the rings and balls. Stainless steel and other customized configurations can be supplied for specific applications.

What sealing options are available for SR620?

The SR620 can be supplied as an open bearing or with ZZ metal shields or 2RS rubber seals.