513 Series
Medium Thrust Ball Bearings
20–340mm Bore | Single Direction | Heavy Cross-Section | P5/P4/P0 Grade
The 513 series features a heavy cross-section for high axial load capacity. Designed for demanding industrial applications — crane hooks, heavy-duty vertical pumps, extruder thrust blocks, and forging press screws — where axial loads significantly exceed the capacity of 511 and 512 series bearings.
Heavy-Duty Axial Support for Demanding Industrial Applications
Luoyang Songju 513 series medium thrust ball bearings feature a substantially larger cross-section than 511 and 512 series — delivering axial load capacities 2-3× higher than equivalent-bore 511 series bearings. The heavy ball complement and robust washers are engineered to survive the repetitive shock loads and continuous high thrust conditions typical of heavy industrial machinery.
The single-direction design with flat housing washer handles pure axial loads in one direction. For bidirectional loads, the 523 series double-direction variant is available. The separable 3-piece construction (shaft washer × 1, housing washer × 1, ball-cage assembly × 1) simplifies mounting, inspection, and individual component replacement.
Standard bore range from 20mm to 340mm. Pressed steel cages as standard; machined brass cages (M suffix) are recommended for high-speed or high-temperature applications above 120°C. For applications with potential shaft-housing misalignment, consider the 533 series with spherical aligning seat.
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513 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) |
|---|---|---|---|---|---|---|
| 51304 | 20 | 42 | 16 | 30.5 | 47.5 | 0.120 |
| 51305 | 25 | 52 | 18 | 39.0 | 67.7 | 0.178 |
| 51306 | 30 | 60 | 21 | 49.2 | 88.3 | 0.278 |
| 51307 | 35 | 68 | 24 | 55.2 | 105.0 | 0.396 |
| 51308 | 40 | 78 | 26 | 72.7 | 138.0 | 0.554 |
| 51309 | 45 | 85 | 28 | 77.5 | 153.0 | 0.698 |
| 51310 | 50 | 95 | 31 | 92.3 | 186.0 | 0.984 |
| 51312 | 60 | 110 | 35 | 119.0 | 248.0 | 1.450 |
| 51314 | 70 | 125 | 40 | 136.0 | 294.0 | 2.150 |
| 51316 | 80 | 140 | 44 | 159.0 | 360.0 | 2.940 |
| 51318 | 90 | 155 | 50 | 185.0 | 425.0 | 4.100 |
| 51320 | 100 | 170 | 55 | 225.0 | 520.0 | 5.420 |
All models available in P5, P4, P0 precision grades. Standard: GCr15 steel, pressed steel cage. M suffix = machined brass cage. For double-direction: 523 series. For spherical aligning: 533 series. Heavy section — verify housing dimensions for adequate radial space.
Why Choose Luoyang Songju 513 Series
Heavy cross-section for 2-3× the axial load capacity of light-series thrust bearings
2-3× Higher Load Capacity
The heavy cross-section accommodates larger ball diameters and more balls per bearing — delivering 2-3× the dynamic and static axial load ratings of equivalent-bore 511 series bearings. Built for industrial applications where axial forces are the primary design consideration.
Shock Load Resistant
Robust washer design with generous ball contact area provides inherent resistance to shock and impact loads. The heavy-section rings absorb and distribute transient load spikes that would brinell the raceways of lighter-series bearings.
Separable Components
Like all single-direction thrust ball bearings, the 513 series features independently replaceable shaft washer, housing washer, and ball-cage assembly. Maintain spare ball-cage assemblies to minimize machine downtime during routine thrust bearing servicing.
Through-Hardened GCr15 Steel
Rings and balls produced from vacuum-degassed GCr15 steel with consistent through-hardness of 58–64 HRC. Tight control of retained austenite ensures dimensional stability under sustained heavy loading and elevated operating temperatures typical of industrial machinery.
Machined Brass Cage Option
M suffix variants feature precision-machined brass cages that provide superior ball guidance at elevated temperatures and under fluctuating loads. Recommended for continuous-duty applications above 120°C or where pressed steel cage fatigue is a concern.
SKF/NTN/NSK Interchangeable
Direct dimensional drop-in replacement for SKF 513, NTN 513, NSK 513, and FAG 513 series. Same mounting dimensions, same heavy-duty performance — competitive pricing with shorter lead times from Luoyang.
Industries & Applications for 513 Series
Trusted across precision industries worldwide for reliable axial load support
Crane Hooks & Lifting Equipment
The classic application for 513 series bearings. Crane hook thrust bearings support the full lifted load on a single bearing while allowing the hook to swivel freely. Safety-critical — 513 bearings are specified with generous static load safety factors in lifting applications.
Heavy-Duty Vertical Pumps
Large vertical turbine pumps, mine dewatering pumps, and circulating water pumps. 513 bearings carry the combined rotating assembly weight plus hydraulic downthrust — often exceeding 50 kN per bearing in large pump installations.
Extruder & Injection Molding
Plastic and rubber extruder screw thrust blocks. 513 bearings handle the high back-pressure thrust generated at the screw tip — continuous loads that would rapidly fatigue lighter-series bearings.
Forging Press Screws
Mechanical and screw forging presses generate extreme axial forces during the forging stroke. 513 series bearings support the press screw while accommodating the rotary motion required for screw-driven ram actuation.
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