Define Permissible Bearing Pressure on poly tetra fluoro ethylene?

For the purpose of design, it is important to lay down permissible bearing pressure on PTFE sliding surfaces. There is no code of practice available in India for this purpose.

The values as given in Table obtained from various technical literature give an idea about the range of the permissible stress in various types of PTFE.

   Table: Permissible Bearing Pressure

BS: 5400 limits the average pressure on PTFE with glass fibres to 45 MPa and PTFE in a metal matrix to 60 MPa. For any material other than the above, permissible values should either be established by tests or the values recommended for unfilled PTFE should be adopted.