IKO SBB20-2RS Spherical Plain Bearing, Inch, Steel-on-Steel, With Seals, 1 1/4 in Bore

This page covers the sealed IKO SBB..-2RS inch series spherical plain bearings (spherical bushings) for 3/4 to 4 in shafts, 16 sizes from SBB12-2RS to SBB64-2RS. Choose the shaft size in inches from the drop-down; each variant has its own dimensions in mm and inches, load capacities and mass in the Model Details.

SBB is the inch series of the steel-on-steel type: inner and outer rings of high carbon chromium bearing steel, with phosphate-treated sliding surfaces that are dry-coated with molybdenum disulfide (MoS2). The outer ring is split at one position, and the -2RS suffix marks the sealed type, which has double-lip polyurethane seals that are effective against grease leakage and dust penetration. The Model Details give each dimension in mm with the inch value in brackets. Each ring has an oil groove and two oil holes.

Where this product is used

• Pivots and linkages in industrial machinery and construction machinery
• Joints with alternate loads and shock loads
• Mountings where the shaft and housing can be slightly out of line and the bearing must self-align
• Joints that carry a radial load and an axial load in both directions at the same time

Features

• Steel-on-steel: high carbon chromium bearing steel rings, phosphate-treated and dry-coated with molybdenum disulfide (MoS2) for low torque, wear resistance and large load capacity
• Self-aligning spherical sliding surfaces that carry a radial load and a bi-directional axial load at the same time
• Sealed type (2RS): double-lip polyurethane seals effective against grease leakage and dust penetration
• Oil groove and two oil holes on the inner ring and on the outer ring
• Dynamic load capacity Cd 38.5 to 1,090 kN and static load capacity Cs 231 to 6,550 kN across the 16 sizes on this page
• Permissible tilting angle 7°

Key specifications

Available sizes

Dimensions are given in mm; the Model Details of each size also give the inch values.

Selecting the right option

The drop-down is the shaft diameter in inches. The size number in the part number is the bore in sixteenths of an inch: SBB12-2RS is a 3/4 in bore (19.05 mm). Every size on this page is an inch size.

The permissible tilting angle of the sealed SBB..-2RS type is 7° (12° without seals). On SBB12-2RS, SBB14-2RS and SBB16-2RS the maximum corner radius rbs of the shaft or housing is 0.4 mm; the 0.8 mm value applies to the same sizes without seals. The 1/2 and 5/8 in sizes without seals are on the SBB page.

Steel-on-steel or maintenance-free is chosen from the operating conditions: load, lubrication, temperature and sliding velocity. This is a steel-on-steel type, which needs periodic grease lubrication and suits alternate loads and shock loads. If you are unsure, send AIMS the load, motion and environment and we will help you choose.

Fitting and use

Recommended fits for steel-on-steel bushings: shaft h6 or j6 with housing bore H7 or J7 for normal operation, and shaft m6 or n6 with housing bore M7 or N7 when the load direction is indeterminate. N7 is recommended for light metal housings.

When the load is large, the shaft can slip in the inner ring bore: prepare the shaft to a hardness of 58 HRC or greater and a surface roughness of 0.8 μm Ra or less.

When mounting, set the split plane of the outer ring at right angles to the direction of the load, so that the load does not act on the split.

Steel-on-steel bushings need periodic grease lubrication as a general rule, and a shorter interval is recommended during initial operation. Lithium soap based grease (NLGI consistency No. 2) containing molybdenum disulfide is widely used.

For steel-on-steel bushings the recommended load is up to 0.3 x Cd for a constant load and up to 0.6 x Cd for an alternate load. Radial and axial loads can act together. The equivalent radial load is P = Fr + Y x Fa, where Y is 1, 2, 3, 4 and 5 for an Fa/Fr of 0.1, 0.2, 0.3, 0.4 and 0.5; an Fa/Fr above 0.5 is marked unusable.

The operating temperature range of bushings with seals is -30 to +80 °C.

Cd is the dynamic load capacity (the maximum allowable load under oscillating motion, based on the contact pressure on the spherical surfaces) and Cs is the static load capacity.

Related products

Other IKO spherical plain bearing pages: SBB inch series spherical plain bearings without seals (1/2 and 5/8 in) and SB..A metric spherical plain bearings (12 to 55 mm).