Pivot bearings · Radial, angular contact and thrust spherical plain bearings and rod ends for oscillating and tilting joints, steel-on-steel for alternating and shock loads or steel/PTFE maintenance-free for constant-direction loads
A pivot bearing lets one part swing, oscillate or tilt about another at a joint — a hydraulic cylinder eye, a linkage pin or a suspension arm. This page covers the spherical plain bearing, an inner ring with a convex sphere inside an outer ring with a concave sphere, or a rod end that carries one in a housing with a threaded shank. Ask three things first: which way the load acts and whether it alternates or shocks, whether the joint can be greased, and what bore, angle of tilt and sealing the joint needs.
Spherical plain bearings (radial, angular contact and thrust) and rod ends used as pivot bearings in linkages, cylinders, suspensions and articulated joints. Rolling bearings such as spherical roller bearings (see spherical roller bearings) and slewing rings (see slewing bearing), linear ball bushings, cross-and-yoke universal joints (see universal joint) and plain cylindrical bushings without a spherical surface are outside this page except where compared.
01
The Bearing Specialists Association (BSA) describes a radial spherical plain bearing as an inner ring with a convex spherical race inside an outer ring with a concave race, designed to support heavy radial loads under misalignment and to accommodate misalignment between shaft and housing and oscillating movements at slow speeds. It lists hydraulic cylinders, vehicle suspensions, articulated joints, heavy-duty linkage pivots and hitch assemblies among applications in mining, off-highway, construction, agriculture and material handling. [1]
BSA divides them into radial bearings, for loads that are mainly radial with a small axial share; thrust bearings, for mainly axial loads; and angular contact bearings, for thrust loads beyond a radial bearing's capacity, single-acting units being mounted in pairs in X or O arrangement. It separates steel-on-steel bearings, which need regular lubrication through holes in the rings and suit heavy alternating, shock or static loads, from maintenance-free bearings with a low-friction composite bonded to the outer race, designed mainly for heavy loads in a constant direction where lubrication is not possible. It also notes loading-slot, double-fractured and single-fractured outer ring designs, the fractured designs being insensitive to load direction when pressed into a rigid housing. [1]
SKF's GE 20 TXG3E is a maintenance-free radial spherical plain bearing with a steel/PTFE fabric sliding pair in stainless steel, described as suited to very heavy constant-direction loads [2]; its SA 8 C rod end contains a spherical plain bearing with a steel/PTFE sintered bronze sliding pair, a steel housing and a right-hand M8 male thread, with left-hand versions under prefix SAL. [3]
Give the supplier the joint drawing, load magnitude and direction (radial, axial, alternating, shock), oscillation angle and frequency, tilt angle needed, whether the joint can be relubricated, environment (dirt, water, corrosion, temperature), bore and housing dimensions or rod-end thread, sealing, material, and quantity.
02
SKF lists the GE 20 TXG3E at 0.787 in bore, 1.378 in outside diameter and 0.472 in outer ring width, with a basic dynamic load rating of 18,659 lbf and a basic static load rating of 31,473 lbf. [2] It lists the SA 8 C rod end at 0.315 in bore and inner ring width, 0.984 in eye diameter, 1.654 in centre height from the shank end, a 15° angle of tilt and basic dynamic and static load ratings of 1,315 lbf and 2,900 lbf. [3]
BSA notes that seals retain lubricant and slow the ingress of contaminants, have a significant effect on service life, and are chosen against tilting angle, environment, space and cost. [1]
Editorial calculation: 0.787 in × 1.378 in × 0.472 in is a 20 × 35 × 12 mm bearing; 18,659 lbf is about 83 kN and 31,473 lbf about 140 kN; the 8 mm rod end's ratings are about 5.85 kN dynamic and 12.9 kN static. [2] [3]
03
FK Rod Ends' CM-M (male thread) and CF-M (female thread) metric rod ends are a 2-piece design with an alloy steel ball, heat treated and hard chrome plated, in a low carbon steel body that is zinc plated and chromate treated; a PTFE liner and a lubrication fitting are options, and FK states its load ratings for rod ends without a lubrication fitting. Its table gives each size's misalignment angle and ultimate static radial load in newtons. [4]
Editorial note: these figures cannot be set directly against SKF's SA 8 C, because the two makers state different quantities. SKF gives a 15° angle of tilt and a basic static load rating of 2,900 lbf for its 8 mm rod end, while FK gives a 28° misalignment angle and an ultimate static radial load of 13,591 N for its CM8M. [3] [4] Editorial calculation: 13,591 N × 0.2248 (FK's own conversion factor) is about 3,055 lbf. [4] Before comparing quotes, ask each supplier whether the angle is per side or total and whether the load is a basic static rating or an ultimate (failure) load, and what safety factor it recommends for working load.
04
No manufacturer record has been reviewed for this product yet. Send your specification and CNFX will match it against manufacturer records.
Ask any supplier for bearing type and series, dimensions to the applicable ISO 12240 part, sliding contact pair, basic dynamic and static load ratings, tilt angle, radial internal clearance, seals, lubrication arrangement, ring material and heat treatment, outer ring design, and corrosion protection.
05
This is a functional reference built from the sources cited; it is not one maker's specification.
| Part | Role | Fix in the order |
|---|---|---|
| Inner ring (convex sphere) | Carries the pin; tilts and turns. [1] | Bore; material. |
| Outer ring (concave sphere) | Seats in the housing. [1] | OD; fracture design. |
| Sliding layer | Steel/steel or steel/PTFE. [1] [2] | Pair. |
| Seals | Keep grease in, dirt out. [1] | Lip type. |
| Rod-end housing and shank | Holds the bearing; threads to the rod. [3] | Thread; hand. |
06
A pivot bearing quotation needs values for your joint. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Type | Radial, angular contact, thrust, rod end. [1] [3] | Series. |
| Bore (mm) | e.g. 8 mm rod end; 20 mm radial bearing. [3] [2] | Bore; tolerance. |
| Outside diameter and width (mm) | e.g. 35 × 12 mm. [2] | Dimensions. |
| Basic dynamic load rating | e.g. 1,315–18,659 lbf. [3] [2] | C. |
| Basic static load rating | e.g. 2,900–31,473 lbf. [3] [2] | C0. |
| Angle of tilt (°) | e.g. 15° rod end. [3] | Tilt. |
| Sliding pair | Steel/steel; steel/PTFE fabric; steel/PTFE sintered bronze. [1] [2] [3] | Pair. |
| Lubrication | Required for steel/steel; none for maintenance-free. [1] | Grease; holes. |
| Seals | Lip seals optional. [1] | Seal type. |
| Material | e.g. stainless steel rings. [2] | Rings; housing. |
| Radial internal clearance | Not stated in the reviewed sources. | Clearance class. |
| Operating temperature (°C) | Not stated in the reviewed sources. | Range. |
07
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Joint: [drawing; pin; housing] Load: [radial; axial; alternating; shock] Motion: [oscillation angle; frequency; tilt] Type: [radial; angular contact; thrust; rod end] Sliding pair: [steel/steel; steel/PTFE] Lubrication: [possible or not] Environment: [dirt; water; corrosion; temperature] Quantity: [pieces]
These companies list the product on their own websites. The listing does not verify a factory or tested performance.
Lists spherical plain bearings, alongside spherical roller, tapered, cylindrical and thrust bearings.
Product scope checked 2026-10-12
Lists GE..ES radial spherical plain bearings, alongside SA and SI series rod ends and hydraulic cylinder rod ends.
Product scope checked 2026-10-12
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
BSA says they suit heavy constant-direction loads where lubrication is not possible; steel-on-steel suits alternating and shock loads. [1]
BSA says radial ones take mainly radial loads and thrust ones mainly axial loads; angular contact ones take both. [1]
SKF lists a 15° angle of tilt for its SA 8 C rod end. [3]
Sources checked 2026-10-11. The Bearing Specialists Association publishes bearing briefs; SKF and FK Rod Ends make spherical plain bearings and rod ends, and each states its own rating basis.
Ask for use case, specification boundaries, supplier type, and RFQ preparation information for this product.
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