Product Name: SR1028 Low Noise EMQ Bearing
Category: Miniature & Small Deep Groove Ball Bearing — EMQ Grade
Manufacturer: Mighty Way Industrial Limited (MTWB)
Application Focus: Precision instrumentation, dental handpieces, medical devices, power hand tools, and low-noise motor applications
The SR1028 is an inch-series miniature deep groove ball bearing engineered to Electric Motor Quality (EMQ) standards. With a bore of 0.625" (15.875 mm), an outside diameter of 0.875" (22.225 mm), and a width of 0.1562" (3.97 mm), it occupies a distinctive position in the mini-to-small bearing spectrum — substantially larger than conventional micro bearings yet compact enough for space-constrained assemblies.
This bearing is manufactured under MTWB EMQ protocol, which combines super-finished raceways, tight geometric tolerances, and 100% noise inspection to deliver measurably lower vibration and acoustic output than standard deep groove ball bearings. It is available with metal shields (ZZ) or rubber seals (2RS), and in open configuration for oil-lubricated assemblies.
Parameter Value
Bore Diameter (d) 0.6250" (15.875 mm)
Outside Diameter (D) 0.8750" (22.225 mm)
Width (B) 0.1562" (3.97 mm)
Bore Tolerance −0.008 mm to 0
OD Tolerance −0.009 mm to 0
Width Tolerance −0.12 mm to 0
Precision Class ABEC 5 (P5)
Material (Rings & Balls) 440C Stainless Steel
Cage Material 440C Stainless Steel
Seal/Shield Options ZZ (metal shield) / 2RS (rubber seal) / Open
Dynamic Radial Load 218 lbf (≈ 970 N)
Static Radial Load 139 lbf (≈ 618 N)
Max Speed (Grease) 10,000 RPM
Temperature Range −86 °F to 230 °F (−66 °C to 110 °C)
Radial Clearance C0 (0.003–0.018 mm)
Weight 3.95 g
Compliance RoHS, REACH
For other miniature low-noise applications, see our
SR620 Bearing,
SR824 Bearing,
SR1232 Bearing
The SR1028 is manufactured to EMQ (Electric Motor Quality) standards, achieving noise and vibration levels rated ZV2 (low noise) or ZV3 (very low noise), depending on configuration. This is accomplished through:
●Mirror-Finish Raceways: Rolling contact surfaces are super-finished to eliminate the micro-asperities that generate high-frequency acoustic emissions during rotation.
●100% Anderon Noise Testing: Every bearing undergoes noise inspection on an Anderon meter prior to lubrication and packaging, measuring vibration velocity across three frequency bands.
●Precision Ball Geometry: Balls are selected for sphericity and surface finish within sub-micron tolerances, reducing the discrete frequency noise that arises from imperfect rolling elements .
Both rings and balls are fabricated from 440C martensitic stainless steel — a through-hardening alloy that combines high hardness (HRC 58–62) with excellent corrosion resistance. This makes the SR1028 suitable for humid, mildly corrosive, or sterilization-exposed environments where standard chrome steel bearings would degrade.
The C0 radial clearance range (0.003–0.018 mm) is deliberately narrow. Excessive clearance is one of the primary contributors to bearing vibration and noise; the SR1028’s tight clearance band ensures consistent, smooth rotation across the speed range.
●ZZ (Metal Shield): Non-contact shield for high-speed applications where minimal drag is critical.
●2RS (Rubber Seal): Contact seal for environments with dust, coolant mist, or fine particulate — common in power tool and dental applications.
The SR1028 is manufactured to ABEC 5 (P5) tolerance class, controlling roundness, concentricity, runout, and parallelism to levels that directly suppress the low-frequency vibration associated with geometrically imperfect rings.
While the SR1028 can be used in power hand tools, it is not a commodity power tool bearing. The distinction lies in engineering priorities.
Noise and Vibration Standard
Power hand tool bearings are typically specified to EMQ as a minimum requirement — the tool must run without objectionable rattle, but the acoustic floor is set by the operator’s tolerance, not by instrumentation. The SR1028 is engineered to EMQ as a performance target: every unit is Anderon-tested, and the rejection threshold is tighter than what most power tool OEMs specify. In a drill or grinder, this difference may be imperceptible. In a dental handpiece or laboratory instrument, it is the difference between an acceptable product and a rejected one.
Material Selection
The majority of power tool bearings are manufactured from GCr15 (52100 chrome steel), chosen for load capacity and cost efficiency. The SR1028 uses 440C stainless steel. This trades a modest reduction in dynamic load rating (218 lbf vs. the ≈ 260–280 lbf typical of an equivalent GCr15 bearing) for corrosion resistance that chrome steel cannot provide. For a power tool used in a dry workshop, the GCr15 bearing is the rational choice. For a handpiece exposed to repeated steam sterilization, The SR1028 is well suited to handpiece applications where corrosion resistance, low vibration and precision are important.
Clearance Philosophy
Power tool bearings often run with looser radial clearance (C2–C3 in many drill and impact driver designs) because the application tolerates and sometimes requires clearance to accommodate thermal expansion and shaft deflection under impact loads. The SR1028 C0 clearance is deliberately tight. This reduces noise but demands more precise shaft and housing fits — a trade-off that makes sense in instrumentation but would be impractical in a high-volume power tool assembly line.
Precision Class
Power tool bearings are commonly manufactured to ABEC 1 or ABEC 3. The SR1028 is ABEC 5. The additional geometric control directly reduces the runout and non-repeatable rotational error that manifests as low-frequency vibration — precisely the vibration that EMQ testing is designed to detect and reject.
MTWB has developed proprietary grinding and super-finishing processes specifically for miniature and small deep groove ball bearings in the 0.6 mm to 30 mm bore range. The SR1028 benefits from these capabilities in three ways:
1.Raceway topography control. MTWB grinding protocols target a specific surface texture (Ra and Rsk) that minimizes both asperity contact noise and lubricant film disruption. This is not a generic “fine grinding” operation — it is a parameter set developed through correlation of surface metrology with Anderon noise readings.
2.100% sealing integrity inspection. Before shipment, every sealed or shielded SR1028 bearing is inspected for sealing effectiveness. Inadequate sealing allows particulate ingress that degrades noise performance over time — a failure mode that does not appear in short-duration factory tests but emerges in field use.
3.Lubricant selection matched to application. MTWB supplies the SR1028 with lithium-based grease for closed configurations or anti-rust oil for open bearings, with the option to specify customer-preferred lubricants. Grease choice is a first-order variable in bearing noise — a “quiet” bearing with the wrong grease is not a quiet bearing.
4.Measurable performance verification. MTWB quality documentation for EMQ bearings includes Anderon noise test data by batch, not simply a certificate of conformity. Buyers can correlate incoming inspection results with the manufacturer records.
What is an SR1028 bearing?
SR1028 is an inch-series miniature deep groove ball bearing designed for low-noise and precision applications, with a 15.875 mm bore, 22.225 mm outside diameter and 3.97 mm width.
Is the SR1028 bearing suitable for dental handpieces?
Yes. The low-noise EMQ design, 440C stainless steel construction and ABEC 5 precision make the SR1028 suitable for dental handpieces and other precision medical equipment where low vibration and corrosion resistance are required.
What material is used for the SR1028 bearing?
The SR1028 uses 440C stainless steel for the rings and balls, providing high hardness and corrosion resistance.
What sealing options are available for SR1028?
The bearing can be supplied with ZZ metal shields, 2RS rubber seals, or in an open configuration depending on the application.
What is the SR1028 bearing size?
The SR1028 has a 0.625 inch (15.875 mm) bore, 0.875 inch (22.225 mm) outside diameter and 0.1562 inch (3.97 mm) width.
October 14,2026
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