Miniature & Extra Small Ball Bearings
639 Miniature & Extra Small Ball Bearing
9 × 30 × 10 mm
639 is a miniature & extra small ball bearing from the MX-3 series with a 9 mm bore, a 30 mm outside diameter and a 10 mm width. It has a dynamic load rating of 4,590 N and a static load rating of 2,151 N and a speed rating of 23,400 rpm (oil lubrication), weighing about 34 g. The radial cross-section (D − d) is 21 mm.
Brands: NTN, FAG, SKF, NBC, DTC, SLS
639 Specifications
| Bearing No. | 639 |
|---|---|
| d (Bore) | 9 mm |
| D (Outer Dia.) | 30 mm |
| B (Width) | 10 mm |
| Dynamic Load | 4,590 N |
| Static Load | 2,151 N |
| Max. RPM | 23,400 |
| Weight | 34 g |
| Series | Open Type Miniature & Extra Small Ball Bearings (6mm–9mm bore) |
639 Variants & Designations
Typical designations for this size, subject to availability. Full suffix meanings are listed on the MX-3 series page.
639-ZZ
metal shields on both sides
639-2RS
rubber seals on both sides
Neighbouring Sizes in the MX-3 Series
639 — Frequently Asked Questions
What are the dimensions of the 639 bearing?
The 639 has a bore (d) of 9 mm, an outside diameter (D) of 30 mm and a width of 10 mm, so it is written 9 × 30 × 10 mm.
What is the load rating of the 639?
Dynamic load rating 4,590 N and static load rating 2,151 N. The speed rating is 23,400 rpm with oil lubrication; for grease lubrication use about 75% of that value.
Is the 639 available with seals, special clearance or other options?
Yes, subject to availability. Typical designations include 639-ZZ (metal shields on both sides), 639-2RS (rubber seals on both sides). Tell us the exact designation you need in a quote request.
Which other bearings have the same 9 mm bore as the 639?
Other miniature & extra small ball bearings with a 9 mm bore include F689 (17 mm OD), 689 (17 mm OD), F699 (19 mm OD), 699 (20 mm OD). A larger outside diameter generally means a higher load rating.
Do you supply the 639 bearing across India?
Yes. Logass Trade Centre supplies the 639 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 639?
Share your quantity and preferred brand — our technical team will confirm availability and pricing within one business day.