512 Series
Light Thrust Ball Bearings
10–300mm Bore | Single Direction | Flat Back Face | P5/P4/P0 Grade
The 512 series offers a larger cross-section than 511 for the same bore size, delivering significantly higher axial load capacity. The single-direction design with flat housing washer is the most widely specified thrust bearing for machine tool spindle thrust blocks, rotary indexing tables, and general medium-load axial applications.
The Industry Workhorse for Medium Axial Loads
Luoyang Songju 512 series light thrust ball bearings provide 30–50% higher axial load capacity than equivalent-bore 511 series bearings — making them the most popular choice for general industrial axial load applications. The increased cross-section accommodates larger ball diameters, directly translating to higher dynamic and static load ratings.
The separable 3-piece design (shaft washer + housing washer + ball-cage assembly) enables independent mounting of each component. The shaft washer bore is precision-ground for interference fit; the housing washer has a clearance bore. This interchangeability simplifies maintenance — replace only the worn component rather than the complete bearing assembly.
Standard bore range covers 10mm to 300mm. Pressed steel cages as standard; machined brass cages (M suffix) for demanding applications. For bidirectional axial loads, the 522 series double-direction variant shares the same 512 cross-section. Spherical aligning seat variant (532 series) compensates for static angular misalignment between shaft and housing.
Request Quote
512 Series Model Parameters
Complete standard model list. d = Bore, D = Outer diameter, T = Height, Ca = Dynamic axial load, C0a = Static axial load. Data per SKF/NTN/NSK catalogs.
| Model | d (mm) | D (mm) | T (mm) | Ca (kN) | C0a (kN) | Mass (kg) |
|---|---|---|---|---|---|---|
| 51200 | 10 | 26 | 11 | 12.7 | 17.1 | 0.030 |
| 51201 | 12 | 28 | 11 | 13.2 | 19.0 | 0.034 |
| 51202 | 15 | 32 | 12 | 16.6 | 24.8 | 0.046 |
| 51203 | 17 | 35 | 12 | 17.2 | 27.3 | 0.052 |
| 51204 | 20 | 40 | 14 | 22.8 | 37.7 | 0.082 |
| 51205 | 25 | 47 | 15 | 27.8 | 50.4 | 0.110 |
| 51206 | 30 | 52 | 16 | 29.3 | 58.2 | 0.138 |
| 51207 | 35 | 62 | 18 | 39.4 | 78.2 | 0.220 |
| 51208 | 40 | 68 | 19 | 47.3 | 98.2 | 0.278 |
| 51209 | 45 | 73 | 20 | 48.5 | 105.0 | 0.310 |
| 51210 | 50 | 78 | 22 | 52.5 | 118.0 | 0.374 |
| 51212 | 60 | 95 | 26 | 73.3 | 172.0 | 0.714 |
| 51214 | 70 | 105 | 27 | 76.6 | 198.0 | 0.840 |
| 51216 | 80 | 115 | 28 | 86.2 | 236.0 | 0.968 |
| 51218 | 90 | 135 | 35 | 125.0 | 340.0 | 1.860 |
| 51220 | 100 | 150 | 38 | 136.0 | 390.0 | 2.400 |
All models available in P5, P4, P0 precision grades. Standard: GCr15 steel, pressed steel cage. M suffix = machined brass cage. For double-direction: 522 series. For spherical aligning: 532 series. Contact engineering for complete catalog.
Why Choose Luoyang Songju 512 Series
The most popular thrust ball bearing — 30–50% more load capacity than 511 series for general industrial applications
30-50% Higher Load Rating
The increased cross-section of the 512 series accommodates larger ball diameters — directly increasing dynamic and static axial load capacity versus the 511 series. Essential for machine tool thrust blocks where cutting forces generate substantial axial loads.
Separable & Interchangeable
All three components (shaft washer, housing washer, ball-cage assembly) are independently replaceable. If only the ball-cage assembly shows wear, replace it alone — no need to discard perfectly good washers. Reduces maintenance inventory cost.
Machine Tool Standard
512 series is the most common thrust bearing in CNC lathe and milling machine spindle thrust blocks. Paired with radial bearings (cylindrical roller or angular contact) to form the complete spindle bearing arrangement.
Thermally Stable Design
The flat housing washer allows the bearing to accommodate slight axial thermal expansion of the shaft without inducing radial loads. This is critical in machine tool spindles where temperature gradients between shaft and housing are significant during operation.
Premium GCr15 Steel
Vacuum-degassed GCr15 bearing steel with controlled retained austenite content ensures dimensional stability throughout the bearing service life. 58–64 HRC hardness for optimal wear resistance balanced with toughness for shock load survival.
SKF/NTN/NSK Interchangeable
Direct dimensional drop-in replacement for SKF 512, NTN 512, NSK 512, and FAG 512 series. Same mounting envelope, same performance — competitive pricing and faster delivery from Luoyang.
Industries & Applications for 512 Series
Trusted across precision industries worldwide for reliable axial load support
CNC Machine Tool Spindles
Thrust blocks in CNC lathes, milling machines, and drilling centers. 512 bearings handle the axial cutting forces while cylindrical roller or angular contact bearings manage radial loads. The standard arrangement for production machine tool spindles.
Rotary Indexing Tables
Precision rotary tables and indexers in machining centers. 512 bearings support the table weight and workpiece clamping forces while maintaining precise axial positioning and smooth rotary motion.
Vertical Pump & Motor Thrust
Vertical turbine pumps, submersible pumps, and vertical motors. 512 bearings carry the combined weight of the rotating assembly plus hydraulic thrust in the downward direction.
Automotive Transmissions
Manual and automatic transmission thrust washers and bearing assemblies. The compact cross-section of 512 series fits within the tight confines of transmission housings while handling gear-generated axial thrust loads.
Need 512 Series Light Thrust Ball Bearings?
Tell us your bore size, precision grade, cage preference, and quantity. Our engineers respond within 24 hours.