Product Details

Double Row Different Diameter Ball Slewing Bearing

The double-row ball slewing bearing is an advanced mechanical transmission device that uses double-row spherical rolling elements in its design to meet the needs of high load-bearing capacity and excellent stability. Its structure mainly includes inner and outer rings, double rows of spherical rolling elements, sealing devices and lubrication systems.

The working principle of this slewing bearing is based on the point contact rolling of rolling elements. When an external load acts on the support, the double-row spherical rolling elements roll in point contact between the inner and outer rings, effectively dispersing and transmitting the load. Compared with the single-row ball slewing bearing, the double-row ball-type slewing bearing performs better in terms of load-bearing capacity. Its double-row ball structure provides a larger support area and enhances the stability of the support.

Specification

In terms of application fields, double row ball slewing bearings are widely used in construction engineering, wind power generation equipment, heavy machinery and other fields. In construction projects, it is used for the smooth rotation of tower cranes, cranes and other equipment; in wind power generation equipment, it supports the steering control system of wind turbines; and in the field of heavy machinery, such as mining equipment and excavators, its high load-bearing capacity Making it a critical rotational support.

NO.	De	D	d	H	b	m	z	x	k	Q&T	KG
021.25.500	644	616	384	106	60	5	126	+0.5	0.1	52	130
022.25.500	646. 8	616	384	106	60	6	105	+0.5	0.1	62	130
021.25.560	704	676	444	106	60	5	138	+0.5	0.1	52	146
022.25.560	706. 8	676	444	106	60	6	115	+0.5	0.1	62	147
021.25.630	790. 8	746	514	106	60	6	129	+0.5	0.1	62	173
022.25.630	790. 4	746	514	106	60	8	96	+0.5	0.1	83	170
021.25.710	862. 8	826	594	106	60	6	141	+0.5	0.1	62	190
022.25.710	862. 4	826	594	106	60	8	105	+0.5	0.1	83	187
021.30.800	982. 4	942	658	124	80	8	120	+0.5	0.1	111	305
022.30.800	988	942	658	124	80	10	96	+0.5	0.1	140	307
021.30.900	1086.4	1042	758	124	80	8	133	+0.5	0.1	111	349
022.30.900	1088	1042	758	124	80	10	106	+0.5	0.1	140	348
021.30.1000	1198	1142	858	124	80	10	117	+0.5	0.1	140	396
022.30.1000	1197.6	1142	858	124	80	12	97	+0.5	0.1	167	391
021.30.1120	1318	1262	978	124	80	10	129	+0.5	0.1	140	445
022.30.1120	1317.6	1262	978	124	80	12	107	+0.5	0.1	167	439
021.40.1250	1497.6	1426	1074	160	90	12	122	+0.5	0.1	188	784
022.40.1250	1495.2	1426	1074	160	90	14	104	+0.5	0.1	219	774
021.40.1400	1641.6	1576	1224	160	90	12	134	+0.5	0.1	188	870
022.40.1400	1649.2	1576	1224	160	90	14	115	+0.5	0.1	219	878
021.40.1600	1845.2	1776	1424	160	90	14	129	+0.5	0.1	219	995
022.40.1600	1852.8	1776	1424	160	90	16	113	+0.5	0.1	250	1003
021.40.1800	2055.2	1976	1624	160	90	14	144	+0.5	0.1	219	1147
022.40.1800	2060.8	1976	1624	160	90	16	126	+0.5	0.1	250	1151
021.50.2000	2300.8	2215	1785	190	120	16	141	+0.5	0.1	333	1794
022.50.2000	2300.4	2215	1785	190	120	18	125	+0.5	0.1	375	1780
021.50.2240	2540.8	2455	2025	190	120	16	156	+0.5	0.1	333	2017
022.50.2240	2552.4	2455	2025	190	120	18	139	+0.5	0.1	375	2048
021.50.2500	2804.4	2715	2285	190	120	18	153	+0.5	0.1	375	2246
022.50.2500	2816	2715	2285	190	120	20	138	+0.5	0.1	418	2280
021.50.2800	3110.4	3015	2585	190	120	18	170	+0.5	0.1	375	2553
022.50.2800	3116	3015	2585	190	120	20	153	+0.5	0.1	418	2563
021.60.3150	3536	3428	2872	226	150	20	174	+0.5	0.1	522	4428
022.60.3150	3537.6	3429	2873	227	151	22	158	+0.5	0.1	574	4414
021.60.3550	3936	3828	3272	226	150	20	194	+0.5	0.1	522	5012
022.60.3550	3933.6	3828	3272	226	150	22	176	+0.5	0.1	574	4967
021.60.4000	4395.6	4278	3722	226	150	22	197	+0.5	0.1	574	5706
022.60.4000	4395	4278	3722	226	150	25	173	+0.5	0.1	652	5656
021.60.4500	4879.6	4778	4222	226	150	22	219	+0.5	0.1	574	6293
022.60.4500	4895	4778	4222	226	150	25	193	+0.5	0.1	652	6385

When To Choose This Structure — Slewing Bearing

Sheet 01 · Selection Guide

When Should I Choose This Structure?

Before you place an order, check whether a triple-row roller slewing bearing actually matches your equipment’s duty conditions — faster than reading any spec sheet.

Your equipment needs continuous 360° rotation under high torque, heavy-load conditions — e.g. cranes, excavators, tunnel boring machines, wind turbine yaw systems.
Installation space is limited, and axial load, radial load and tilting moment must be carried by a single bearing rather than a separate bearing-plus-gearbox assembly.
The equipment needs a built-in slewing drive gear (internal or external), eliminating extra transmission components and simplifying assembly.
The operating environment involves dust, moisture, or large temperature swings, requiring a bearing with built-in sealing and lubrication channels.
The project has clear requirements for rotational accuracy and adjustable clearance — e.g. medical equipment, solar tracking mounts, precision turntables.

One-line summary

If your equipment needs to “rotate and carry heavy loads at the same time,” a triple-row roller slewing bearing is usually the most direct, integrated solution.

Typical equipment

Tower crane slewing platforms, crawler crane turntables, excavator upper structures, TBM cutterhead drives, wind turbine yaw/pitch systems, stacker-reclaimer slewing bodies.

When NOT To Choose It — Slewing Bearing

Sheet 02 · When Not To Use

When Should I NOT Choose It?

We’d rather help you find the right solution than sell you the wrong one. Here’s when a slewing bearing may not be the best fit.

If your rotational speed requirement exceeds the typical design range for slewing bearings (e.g. high-speed rotating platforms), a cross roller bearing or dedicated high-speed structure is usually a better fit.
If overall weight is extremely sensitive for the machine (e.g. drone gimbals, small precision instruments), a thin-section or angular-contact bearing combination may be lighter and more suitable.
If budget and production volume favor a standard bearing plus external gear assembly, that may be more cost-effective for non-heavy-duty, non-harsh-environment applications.
If installation space is extremely constrained and cannot meet the minimum installation diameter, confirm with our engineers whether a compact custom design is available.

Not sure which case applies to you?

Send us your equipment’s duty conditions (load / speed / space / environment) and our engineers will tell you within 24 hours whether it fits — not just try to sell you something.

Free Duty Assessment →

Required Data For Selection — Slewing Bearing

Sheet 03 · Selection Data

Required Data For Selection

You don’t need a finished drawing to get started — tell us what you already know, and our engineers will help fill in the rest.

Category	Data Needed	Why It Matters
Load Parameters	Axial load, radial load, tilting moment	Determines the number of rows and raceway design
Envelope Dimensions	Installation OD / ID, installation height, bolt hole pattern	Determines whether a standard size fits or custom sizing is needed
Speed & Duty	Operating speed (rpm), continuous or intermittent duty, environment	Affects lubrication method and seal grade
Drive Type	Internal-tooth / external-tooth / no gear (bearing only)	Determines gear module, tooth count and precision grade
Precision	Rotational accuracy, clearance range (negative clearance required?)	Affects manufacturing process and inspection standard
Drawing / Reference Part	Existing drawing, old bearing model, or competitor part number	Allows a direct 1:1 match or replication — the fastest path to selection

No drawing on hand? That’s fine — send us the parameters you know, or a photo of your old bearing’s nameplate.

Send Data Now →

Materials, Hardness, Clearance & Gear — Slewing Bearing

Sheet 05 · Material & Process

Materials / Hardness / Clearance / Gear Treatment

Every batch ships with a material certificate, hardness test report and NDT report — third-party re-inspection is welcome.

01 · MATERIAL

Ring Material

42CrMo / 50Mn (specifiable)

Determines overall strength and fatigue life. Heavy-duty applications use alloy structural steel with quenching & tempering.

02 · HARDNESS

Raceway Hardness

HRC 55–62, depth customizable

Medium-frequency induction hardening gives more uniform hardness than through-hardening, avoiding soft spots.

03 · CLEARANCE

Clearance Grade

Standard or negative, P0–P6

Heavy-duty, low-speed equipment usually uses negative clearance for higher stiffness; precision equipment can go tighter.

04 · GEAR

Gear Treatment

Q&T or induction-hardened teeth

Frequent start/stop or heavy-duty drive applications benefit from hardened tooth flanks for longer life.

Related Applications — Slewing Bearing

Sheet 06 · Applications

Related Applications

Don’t see your industry? Applications go far beyond the examples below — tell us what your equipment does.

Cranes

Excavators & Construction

Wind Turbines

Solar Tracking

Port Machinery

Rotary Platforms

Real Project Case — Slewing Bearing

Sheet 07 · Project Reference

Real Project Case

More project photos, inspection reports and customer references are available on request — happy to sign an NDA if needed.

Custom triple-row roller slewing bearing manufactured for a stacker-reclaimer, Southeast Asia port project

Case File · Port Machinery

Stacker-Reclaimer Slewing Bearing — Custom Project, SE Asia

Background: The customer was using an imported triple-row roller slewing bearing with a 4-month lead time and a high price point.
Requirement: Find a faster-to-deliver alternative while keeping the original installation dimensions and load parameters unchanged.
Solution: Based on the customer’s original part drawing, we replicated the key dimensions and gear geometry 1:1, and raised raceway hardness to HRC 58–62.

45 DaysLead Time

1:1Dimensional Match

2ndRepeat Order

Slewing Bearing Model Finder

Model Finder

Slewing Bearing Model Finder

Filter 463 catalog specifications by dimension. Results update instantly — no page reload, no server round-trip.

Outer Diameter (mm)

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Inner Diameter (mm)

—

Height (mm)

—

Geared Type

Module (mm)

Number Of Teeth

—

Matching 463 / 463 models

Model	Structure	Geared Type	OD (mm)	ID (mm)	Height	Module	Teeth	Weight (kg)

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Frequently Asked Questions

Expert Insights and Reliable Solutions to Your Most Common Questions.

1. What types of slewing bearings does FDON GROUP provide?

FDON GROUP supplies a full range of slewing bearings to meet different industrial needs:

Single row four point contact slewing bearings Application: medium loads, precise rotation.
Double row ball bearings Application: higher radial and axial loads.
Cross roller bearings –Application: high rigidity, suitable for robots and machining centers.
Three row roller bearings – Application: extreme loads in heavy equipment.
Ball combine roller bearings –Application: precise rotational adjustment applications.
Customized bearings – tailored for specific equipment requirements.

2. How do I choose the right bearing for my application?

Typical selection parameter for FDON clients:

Load type: axial, radial, and tilting moment.

Rotation RPM: ensures long service life.

Installation space & mounting dimensions: inner/outer ring diameter, bolt circle.

Precision & rigidity requirements: critical for cranes, excavators, and robots.

FDON engineers provide professional selection guidance according to your equipment and drawings.

3. What materials does FDON GROUP use for slewing bearings?

FDON GROUP selects materials for strength, wear resistance, and long-term durability:

Slewing ring: 42CrMo, 50Mn, C45N, 40CrNiMo, C48E.

Special forging spare parts: carburized/hardened steels for gear teeth (20CrMnTi, 18CrNiMo7‑6).

Corrosion resistant: SS 304, 316L, duplex stainless steel.

Surface treatments: heat treatment, quenching, carburizing, induction hardening, and surface coating(Four-Layer Packing, Strong Anti-Rust Oil, Black Oxide Treatment, Jet Black Paint Finish, Hot-Dip Galvanizing (CGL), Electro-Galvanizing (EGL), Hot-Dip Galvanizing + Paint Finish)

4. How can FDON GROUP achieve maximum service life?

Correct installation with flat surfaces.

Proper lubrication using grease.

Avoid overloading or shock loads over capacity.

Monitor operating conditions regularly to prevent debris entry.

5. What causes abnormal noise or vibration in bearings?

Typical factors observed by FDON engineers:

Insufficient or incorrect lubrication.
(dust, metal particles) in raceways.
Rolling element or track damage.
Uneven mounting surfaces or misalignment.
Incorrect bolt torque(below grade 8.8) or preloading.

6. What are lead times and lifetime guarantee?

In-stock: 3–7 days.

Custom: 2–6 weeks depending on size, load, and precision.

Warranty: 1 year

Lifetime Free Spare Parts: Glue, seals, steel ball

7. Does FDON provide installation and technical support?

Yes — FDON GROUP offers:

Detailed installation manuals.

Online engineering support.

Guidance for lubrication, maintenance, and troubleshooting solution.

8. How do FDON Group differ from competitors?

Full range of materials and heat treatments for various load conditions.

High precision and strict quality inspection standards.

Engineering support before and after delivery.

Customization to exact equipment requirements.

Proven performance in cranes, excavators, robotics, wind turbines, and heavy machinery etc.

FDON MANUFACTURING CO., LTD

Leading Slew Drive & Slewing Bearing Manufacturer in China.

FDON products are applied globally in solar tracking systems, wind power systems, satellite communications, and numerous other globally connected industries.