Miniature & Extra Small Ball Bearings
R4 Miniature & Extra Small Ball Bearing
6.35 × 15.875 × 4.978 mm
R4 is a miniature & extra small ball bearing from the MX-4 series with a 6.35 mm bore, a 15.875 mm outside diameter and a 4.978 mm width. It has a dynamic load rating of 1,332 N and a static load rating of 553 N and a speed rating of 38,700 rpm (oil lubrication), weighing about 4.4 g. The radial cross-section (D − d) is 9.53 mm.
Brands: NTN, FAG, SKF, NBC, DTC, SLS
R4 Specifications
| Bearing No. | R4 |
|---|---|
| d (Bore) | 6.35 mm |
| D (Outer Dia.) | 15.875 mm |
| B (Width) | 4.978 mm |
| Dynamic Load | 1,332 N |
| Static Load | 553 N |
| Max. RPM | 38,700 |
| Weight | 4.4 g |
| Series | Open Type Miniature & Extra Small Ball Bearings (1.984mm–9.525mm bore) |
R4 Variants & Designations
Typical designations for this size, subject to availability. Full suffix meanings are listed on the MX-4 series page.
R4-ZZ
metal shields on both sides
R4-2RS
rubber seals on both sides
Neighbouring Sizes in the MX-4 Series
R4 — Frequently Asked Questions
What are the dimensions of the R4 bearing?
The R4 has a bore (d) of 6.35 mm, an outside diameter (D) of 15.875 mm and a width of 4.978 mm, so it is written 6.35 × 15.875 × 4.978 mm.
What is the load rating of the R4?
Dynamic load rating 1,332 N and static load rating 553 N. The speed rating is 38,700 rpm with oil lubrication; for grease lubrication use about 75% of that value.
Is the R4 available with seals, special clearance or other options?
Yes, subject to availability. Typical designations include R4-ZZ (metal shields on both sides), R4-2RS (rubber seals on both sides). Tell us the exact designation you need in a quote request.
Which other bearings have the same 6.35 mm bore as the R4?
Other miniature & extra small ball bearings with a 6.35 mm bore include R168 (9.525 mm OD), R188 (12.7 mm OD), R4A (19.05 mm OD). A larger outside diameter generally means a higher load rating.
Do you supply the R4 bearing across India?
Yes. Logass Trade Centre supplies the R4 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 R4?
Share your quantity and preferred brand — our technical team will confirm availability and pricing within one business day.