When to consider relining

Reasons for assessment can include lining wear, seizure, cracks, local loss, geometry changes or suspected loss of bond to the backing. Each case requires a check that the backing remains suitable for service.

Relining should not hide the cause of a failure. Gather information about lubrication, temperature, load, misalignment and contamination before placing the order.

What determines alloy selection

Relevant factors include load, sliding speed, lubrication regime and continuity, temperature, shock, shaft material, lining geometry and backing material.

If machine documentation specifies an alloy, provide the full designation and required standard edition. A material change requires a design assessment.

How to define the refurbishment scope

State the condition after machining, allowances, dimensions and tolerances, required grooves or holes, bond examination and acceptance documents. Photographs before removal and after cleaning are useful.

• drawing and measurements of backing and lining
• service history and failure symptoms
• load, speed, temperature and lubrication data
• required material, machining and delivered condition
• examination, acceptance criteria and report

What the standards cover

ISO 4381:2011 specifies requirements for tin casting alloys used in multilayer plain bearings. It notes that original-material data do not automatically represent results from the finished lining after manufacturing.

ISO 4386-1:2019 describes qualitative ultrasonic testing of the bond within its specified thickness and application range. It is not a quantitative bond-strength test, so the method and acceptance criteria need to be stated in the documentation.