Knuckle Bearing is a pivot-type bearing assembly used in steering and linkage systems that connects two components through a knuckle joint, allowing angular movement while transmitting load, and is commonly applied in automotive steering mechanisms, suspension systems, and heavy machinery where controlled articulation and structural strength are required.
1. Knuckle Body (Housing)
Function:
Main structural component connecting suspension, wheel hub, and steering linkage.
Ductile cast iron (QT450 / ASTM A536) – High strength and vibration damping
Forged carbon steel (C45 / 1045 steel) – Heavy-duty applications
Forged alloy steel (40Cr / 4140) – High impact resistance
Aluminum alloy (Al-Si casting) – Lightweight automotive designs
Forged steel versions provide superior fatigue resistance under dynamic loads.
2. Bearing Element (Rolling or Plain Bearing)
Depending on design, the knuckle may contain:
a) Rolling Bearing (Hub Bearing Type)Deep groove ball bearing or angular contact bearing
Materials:
GCr15 / AISI 52100 bearing steel (rings and balls)
Nylon, steel, or brass cage
b) Plain Bushing (King Pin Type)
Bronze or composite bushings
Materials:
Tin bronze (CuSn12)
Phosphor bronze
Steel-backed PTFE composite bushing
3. King Pin or Pivot Pin
Function:
Provides the rotation axis for steering articulation.
Typical Materials:
Carburized alloy steel (20CrMnTi)
40Cr / 4140 alloy steel
Surface hardened and precision ground
Heat treatment improves wear resistance and fatigue life.
4. Spherical Bearing (Rod-End Type, if applicable)
Function:
Allows angular misalignment in linkage systems.
Typical Materials:
Inner ring: Hardened bearing steel (GCr15)
Outer ring: Carbon steel or stainless steel
Liner: PTFE composite for self-lubrication
5. Seals and Dust Covers
Function:
Prevent contamination and retain lubrication.
Typical Materials:
NBR (nitrile rubber)
FKM (high-temperature applications)
Reinforced steel-backed seals
6. Fasteners and Retainers
Function:
Secure assembly components.
Typical Materials:
High-strength alloy steel (Grade 10.9 / 12.9 bolts)
Zinc or phosphate surface treatment for corrosion protection
Knuckle bearings (commonly referring to spherical plain bearings) specifications are primarily based on international standards (such as ISO 12240) or German DIN standards. Key parameters include inner diameter (d), outer diameter (D), width (B/C), dynamic load (C), and static load (C0).
| Bearing Model | Inner Diameter d (mm) | Outer Diameter D (mm) | Width B/C (mm) | Dynamic load C (kN) | Static load C0 (kN) |
| GE 15 E | 15 | 26 | 12月9日 | 10.6 | 53 |
| GE 20 ES | 20 | 35 | 12月16日 | 21 | 105 |
| GE 25 ES | 25 | 42 | 20/16 | 30 | 150 |
| GE 30 ES | 30 | 47 | 22/18 | 40 | 200 |
| GE 40 ES | 40 | 62 | 28/22 | 65 | 325 |
| GE 50 ES | 50 | 75 | 35/28 | 100 | 500 |
| GE 60 ES | 60 | 90 | 44/36 | 156 | 780 |
| GE 80 ES | 80 | 120 | 55/45 | 255 | 1270 |
| GE 100 ES | 100 | 150 | 70/55 | 390 | 1950 |
Parameter Description
GE…E: Sliding surface is steel/steel, no seal.
GE…ES: Sliding surface is steel/steel, with a seal.
Dynamic Load C : Rated load that the bearing can withstand under sliding conditions.
Static Load C0 : Maximum load capacity of the bearing under static or slow oscillation conditions.
Accuracy Class: Typically P0, P6, P5, etc., conforming to DIN or ISO standards.
Forged alloy steel or ductile cast iron construction
Optimized structural design for impact resistance
Suitable for heavy-duty and high-load applications
Hardened king pins and pivot surfaces
Premium bronze bushings or high-grade bearing steel rolling elements
Extended service life under frequent steering cycles
Accurate pivot alignment
Reduced vibration and noise
Improved steering stability and safety
High-quality NBR or FKM sealing systems
Surface treatments such as phosphating or zinc coating
Reliable performance in harsh environments
We provide:
King pin type knuckle bearings
Integrated hub knuckle assemblies
Spherical (rod-end) knuckle bearings
Custom load and size solutions
Automotive Industry
Passenger vehicle steering systems
Light and heavy trucks
Suspension and wheel hub assemblies
Construction & Heavy Equipment
Excavators
Loaders
Agricultural machinery
Off-road vehicles
Industrial Machinery
Hydraulic linkage systems
Mechanical pivot joints
Automation equipment
Transportation Equipment
Buses and commercial vehicles
Trailer axle systems
Stable production capacity for OEM and aftermarket supply
Strict quality inspection and load testing
Competitive pricing for wholesale distribution
Custom manufacturing support for special applications
Reliable export experience for global markets
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Hi, I am Maxwell, I am an engineer in the field of bearing applications. I majored in mechanical and electromechanical engineering during college. After graduation, I worked for the top three "SKF" bearing companies in the world for ten years , during which I went to dozens of customers in different industries to help them solve problems in bearing applications; later I joined VKUKEN Bearing Manufacturing, and I will share bearing technical knowledge on this website from time to time. If you are a customer Please contact me to help you solve your problem; if you are also a technical expert in bearings, I am very willing to exchange technical knowledge about bearings with you.
