SR1232 is a precision miniature inch-series deep groove ball bearing manufactured to EMQ (Electric Motor Quality) grade, specifically engineered for ultra-low noise and minimal vibration operation. As part of MTWB's miniature-to-small DGBB technical breakthrough program, this bearing combines advanced raceway grinding technology with stringent 100% noise inspection to deliver whisper-quiet performance in space-constrained, noise-sensitive applications.
The SR1232 features a 3/4" bore × 1" outer diameter × 0.1562" width configuration, making it a direct drop-in solution for inch-series miniature bearing applications requiring rotational accuracy within tight tolerances.
Parameter Specification
Bore Diameter (d) 0.7500" (19.05 mm)
Outer Diameter (D) 1.0000" (25.40 mm)
Width (B) 0.1562" (3.97 mm)
Bearing Type Single-row deep groove ball bearing, inch series
Precision Class ABEC-3 / P6 (higher grades available on request)
EMQ Noise Rating Z3/V3 standard; Z4/V4 premium option available
Material (Rings & Balls) 440C stainless steel (AISI 440C / SUS440C) or GCr15 chrome steel
Cage Material Crown-type steel or nylon (application dependent)
Closure Options Open, Z (single shield), ZZ (double shield), 2RS (double rubber seal)
Lubrication Lithium-based grease (sealed); antirust oil (open)
Operating Temperature −40°C to +200°C (grease dependent)
Dynamic Load Rating (Cr) ~227 lbf (approx. 1,010 N)
Static Load Rating (Cor) ~155 lbf (approx. 690 N)
Max Speed (Grease) 8,500 RPM (shielded version)
Weight (approx.) 0.01–0.015 kg per piece
Note: Load ratings and speed limits vary by closure type, lubrication, and cage configuration. Contact our engineering team for application-specific verification.
SR1232 Bearing Dimensions and Applications
The SR1232 bearing features a 3/4 inch bore, 1 inch outside diameter and 0.1562 inch width. This compact inch-series deep groove ball bearing is designed for low-noise and precision applications where limited installation space, rotational accuracy and reduced vibration are important.
EMQ (Electric Motor Quality) is not merely a marketing label — it is a measurable acoustic specification. Standard bearings may pass dimensional tolerance checks yet still generate unacceptable vibration under load. EMQ-grade bearings undergo additional manufacturing controls specifically targeting noise reduction.
MTWB EMQ process implements targeted quality control during inner ring raceway grinding, which is the single most critical factor in reducing bearing acoustic noise. Every SR1232 bearing is 100% inspected for sealing integrity before shipment to prevent dust ingress that could degrade long-term noise performance.
Noise grades explained:
Grade Relative Noise Level Typical Application
Z1/V1 Standard General-purpose machinery
Z2/V2 Low noise (~3–5 dB below Z1) Standard electric motors
Z3/V3 Very low noise (~3–5 dB below Z2) Precision motors, medical devices
Z4/V4 Ultra-low noise (premium silent grade) High-end instrumentation, audiophile equipment
The SR1232 is supplied at Z3/V3 as standard, with Z4/V4 available as a premium option for the most demanding acoustic environments. All bearings are tested using calibrated noise testers and vibration testers to verify conformance before release.
For other miniature low-noise applications, see our
●EMQ-grade low noise performance — Z3/V3 standard, Z4/V4 optional, verified through 100% acoustic inspection
●High-precision raceway geometry — optimized curvature design reduces friction and extends service life
●Stainless steel construction — 440C martensitic stainless steel offers corrosion resistance, high hardness, and excellent fatigue strength
●Compact inch-series footprint — 3/4" × 1" × 0.1562" dimensions suit space-limited housings
●Multiple closure options — open, shielded, or sealed to match contamination and lubrication requirements
●High-speed capability — up to 8,500 RPM (grease-lubricated, shielded configuration)
●Stable performance across temperature extremes — effective from −40°C to +200°C
Medical Devices & Surgical Instruments — Miniature bearings in surgical handpieces must operate at speeds up to 80,000 RPM while maintaining precise tool guidance and patient safety. The SR1232's low-noise EMQ construction makes it suitable for dental handpieces, surgical drills, and precision medical pumps.
Precision Electric Motors — Small motors for office equipment, laboratory instruments, and automation systems benefit from the SR1232's reduced vibration profile, which minimizes acoustic interference and extends motor service life.
Robotics & Mechatronics — Joint actuators and linear motion systems in compact robotic platforms require bearings that combine rotational accuracy with minimal backlash.
Optical & Laboratory Instruments — Flow meters, gyroscopes, and analytical equipment demand vibration-free bearing operation to maintain measurement integrity.
Industrial Automation — Miniature conveyor systems, sorting mechanisms, and precision positioning stages.
1.Measurable acoustic performance — Not a subjective claim. Z3/V3 and Z4/V4 ratings correspond to standardized decibel thresholds verified through instrumented testing.
2.Inch-series precision without metric compromise — True 3/4" × 1" dimensions, not a metric approximation. Drop-in replacement for existing inch-series designs.
3.440C stainless steel as standard — Provides corrosion resistance superior to GCr15 chrome steel, extending service life in humid or mildly corrosive environments.
4.100% sealing inspection before shipment — MTWB factory protocol requires every bearing to pass individual seal integrity verification.
5.Proven miniature bearing expertise — MTWB manufactures bearings down to 0.6 mm ID at P4 precision class, demonstrating capability in the most extreme miniature bearing manufacturing challenges.
What are the dimensions of the SR1232 bearing?
The SR1232 bearing has a 3/4 inch bore, 1 inch outside diameter and 0.1562 inch width.
Is the SR1232 a low-noise bearing?
Yes. The SR1232 is designed as an EMQ-grade low-noise bearing, with Z3/V3 as the standard noise and vibration grade and Z4/V4 available for selected applications.
What applications use SR1232 bearings?
SR1232 bearings can be used in precision electric motors, medical devices, laboratory instruments, optical equipment, robotics and compact automation systems.
Is SR1232 an inch-series bearing?
Yes. SR1232 is an inch-series deep groove ball bearing with a 3/4 inch bore.
What closure options are available for SR1232?
The bearing can be supplied in open, shielded and sealed configurations, including Z, ZZ and 2RS options depending on the application.
October 14,2026
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