Miniature & Extra Small Ball Bearings
R166 Miniature & Extra Small Ball Bearing
4.762 × 9.525 × 3.175 mm
R166 is a miniature & extra small ball bearing from the MX-4 series with a 4.762 mm bore, a 9.525 mm outside diameter and a 3.175 mm width. It has a dynamic load rating of 639 N and a static load rating of 241 N and a speed rating of 49,500 rpm (oil lubrication), weighing about 0.8 g. The radial cross-section (D − d) is 4.76 mm.
Brands: NTN, FAG, SKF, NBC, DTC, SLS
R166 Specifications
| Bearing No. | R166 |
|---|---|
| d (Bore) | 4.762 mm |
| D (Outer Dia.) | 9.525 mm |
| B (Width) | 3.175 mm |
| Dynamic Load | 639 N |
| Static Load | 241 N |
| Max. RPM | 49,500 |
| Weight | 0.8 g |
| Series | Open Type Miniature & Extra Small Ball Bearings (1.984mm–9.525mm bore) |
R166 Variants & Designations
Typical designations for this size, subject to availability. Full suffix meanings are listed on the MX-4 series page.
R166-ZZ
metal shields on both sides
R166-2RS
rubber seals on both sides
Neighbouring Sizes in the MX-4 Series
R166 — Frequently Asked Questions
What are the dimensions of the R166 bearing?
The R166 has a bore (d) of 4.762 mm, an outside diameter (D) of 9.525 mm and a width of 3.175 mm, so it is written 4.762 × 9.525 × 3.175 mm.
What is the load rating of the R166?
Dynamic load rating 639 N and static load rating 241 N. The speed rating is 49,500 rpm with oil lubrication; for grease lubrication use about 75% of that value.
Is the R166 available with seals, special clearance or other options?
Yes, subject to availability. Typical designations include R166-ZZ (metal shields on both sides), R166-2RS (rubber seals on both sides). Tell us the exact designation you need in a quote request.
Which other bearings have the same 4.762 mm bore as the R166?
Other miniature & extra small ball bearings with a 4.762 mm bore include R156 (7.938 mm OD), R3 (12.7 mm OD). A larger outside diameter generally means a higher load rating.
Do you supply the R166 bearing across India?
Yes. Logass Trade Centre supplies the R166 Pan India with technical support, from single pieces to bulk orders. Use the quote button to share your quantity and brand preference.
Need pricing on the R166?
Share your quantity and preferred brand — our technical team will confirm availability and pricing within one business day.