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Brand: NSK
NSK QJ210 Four-Point-Contact Ball Bearing
Description
A four-point-contact bearing for high axial loads in either direction
The NSK QJ210 is a four-point-contact ball bearing with a 50 mm bore, 90 mm outside diameter and 20 mm width. Its inner ring is split radially into two pieces, which lets a single bearing sustain significant axial loads in either direction. The contact angle is 35 degrees, so axial load capacity is high, and NSK states that these bearings suit pure axial loads or combined loads where the axial component dominates. The cage is machined brass. Four-point bearings are used as thrust-locating bearings next to a cylindrical roller bearing in gearboxes, pumps and compressors, where the roller bearing carries the radial load and the QJ locates the shaft axially.
Technical specifications
| Parameter | Specification |
|---|---|
| Designation | QJ210M: QJ = four-point-contact ball bearing, 2 = 02 series, 10 = 50 mm bore, M = machined brass cage |
| Bore d / outside D / width B | 50 mm / 90 mm / 20 mm |
| Chamfer r (min.) | 1.1 mm |
| Basic dynamic axial load rating Ca | 63,000 N |
| Basic static axial load rating C0a | 97,000 N |
| Contact angle | 35 degrees |
| Limiting speed, grease / oil | 5,600 rpm / 8,000 rpm |
| Load centre spacing a0 | 49.0 mm |
| Cage | Machined brass |
| Equivalent load | Dynamic Pa = Fa; static P0a = Fa (pure axial rating) |
| Mass (approx.) | 0.59 kg |
Size table for the NSK QJ2 series
Ratings below are the axial ratings printed in the NSK four-point-contact bearing table.
| Designation | d mm | D mm | B mm | Ca N | C0a N | Grease rpm | Oil rpm | Load centre a0 mm | Mass kg |
|---|---|---|---|---|---|---|---|---|---|
| QJ206 | 30 | 62 | 16 | 34,000 | 45,000 | 8,500 | 12,000 | 32.2 | 0.24 |
| QJ207 | 35 | 72 | 17 | 45,000 | 61,500 | 7,500 | 10,000 | 37.5 | 0.35 |
| QJ208 | 40 | 80 | 18 | 53,500 | 77,500 | 6,700 | 9,000 | 42.0 | 0.45 |
| QJ209 | 45 | 85 | 19 | 60,000 | 88,500 | 6,300 | 8,500 | 45.5 | 0.52 |
| QJ210 | 50 | 90 | 20 | 63,000 | 97,000 | 5,600 | 8,000 | 49.0 | 0.59 |
| QJ211 | 55 | 100 | 21 | 78,000 | 122,000 | 5,300 | 7,100 | 54.3 | 0.77 |
| QJ212 | 60 | 110 | 22 | 94,000 | 150,000 | 4,800 | 6,300 | 59.5 | 0.98 |
| QJ213 | 65 | 120 | 23 | 107,000 | 179,000 | 4,300 | 6,000 | 64.8 | 1.2 |
Mounting and selection notes
The designation is built from the bearing type QJ, the dimension series digit and the bore number, followed by the cage code M and an internal clearance code. C3 and C4 clearances are larger than normal, and NSK gives the clearance classes in its technical tables for four-point bearings. Because the bearing contacts the ball at two points on each side of the split inner ring, the housing is usually made with a little radial clearance so that the outer ring does not take radial load, leaving the cylindrical roller bearing alongside to carry it; check the supplier drawing and the maker guidance before fixing the fit.
Do not use a four-point bearing for pure radial load, and keep a minimum axial load on the bearing so the balls maintain two-point contact. For deep groove bearings with a lower axial capacity see the SKF 6206-2RS1, and for other bearings and drive components browse Electric Motors, Pumps and Turbines.
When ordering, state the full designation including the cage and split-ring suffixes, and the operating temperature if it is above normal. Mounting and dismounting are easier when the split inner ring is fitted with care so that the two halves stay aligned and the ball set is not pinched.
Documents and ordering
Confirm bore, internal clearance, cage, tolerance class, the axial load direction and size, and the shaft and housing fits. The attached PDF is a page extract from NSK catalogue Rolling Bearings for Industrial Machinery (Cat. No. E1103b) with the designation notes and four-point-contact bearing tables. Seven Star LLC is an independent supplier in Muscat; stock and lead time are confirmed per enquiry.
Datasheets & Documents
- Catalog NSK Rolling Bearings for Industrial Machinery E1103b - extract: four-point-contact ball bearings, QJ2 series Download
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About brand
NSK is a Japanese manufacturer of bearings and motion and control components and the largest bearing maker in Japan. The company was founded in Tokyo in 1916, when it also produced its first bearings, and it was the first company to make ball bearings in Japan. NSK Ltd. is headquartered in Shinagawa, Tokyo, and listed on the Tokyo Stock Exchange.
Seven Star LLC is an independent supplier in Muscat. We list NSK catalogue bearings for maintenance teams, workshops and machine builders in Oman and the GCC.
NSK company profile
| Founded | 1916, Yurakucho, Tokyo, Japan (predecessor partnership 1914) |
|---|---|
| Headquarters | Ōsaki, Shinagawa, Tokyo, Japan |
| Ownership | Public company, Tokyo Stock Exchange |
| Distinction | First manufacturer of ball bearings in Japan |
| Product families | Deep groove and angular contact ball bearings, cylindrical, tapered and spherical roller bearings, super-precision machine tool bearings, linear guides and ball screws, automotive components |
Milestones
- 1914: The predecessor partnership is set up in Tokyo.
- 1916: NSK is founded and produces its first bearings.
NSK product series
Ball bearings on this site include the 608 extra small and 6208DDU deep groove bearings, the 7208A single-row and 5206 double-row angular contact bearings, the 7304AWDT matched pair, the QJ210 four-point-contact bearing, the BL210 maximum-type bearing, the 51208 single-direction and 52208 double-direction thrust ball bearings and the 30TAC62C ball screw support bearing. Roller bearings include the HR30210J tapered roller bearing and the NU210EW cylindrical roller bearing.
Super precision bearings include the 70BNR10H NSKROBUST angular contact bearing and the N1010MRKR cylindrical roller bearing for machine tool spindles, and the UCP208D1 pillow block unit covers housed bearings.
Where NSK bearings are used
Electric motors, pumps, fans and gearboxes, conveyors, machine tool spindles and ball screw drives, and general industrial machinery. Each product page quotes dimensions, load ratings and limiting speeds as printed in the NSK catalogue.
NSK products we list
Ordering NSK bearings: what we need
Give the complete designation marked on the bearing, including prefix and suffix letters such as seal, cage, clearance and precision codes. If the marking is worn, measure bore, outside diameter and width and tell us the machine and shaft position, the operating speed and the lubrication. State the quantity and any precision class or special clearance required.
Facts checked against NSK's own company history (nsk.com), October 2026.
Browse NSK products by category: Ball Bearings.
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Frequently Asked Questions
Why is it called a four-point-contact bearing?
The inner ring is split into two halves, so each ball touches the raceways at four points. NSK states this lets one bearing take significant axial load in either direction.
What is the contact angle of the QJ210?
NSK lists a contact angle of 35 degrees for four-point-contact bearings, giving high axial capacity.
What load ratings does the QJ210 have?
The basic dynamic axial rating Ca is 63,000 N and the basic static axial rating C0a is 97,000 N.
Can the QJ210 carry radial load?
NSK suggests these bearings for pure axial or axial-dominant combined load; the catalogue ratings are axial ratings and the equivalent load is the axial load.
What cage does the QJ210 have?
The cage is machined brass, shown by the M in QJ210M.
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