Lumsden grinding or surface grinding is the process of removing stock material and providing a finish to steel plates or profiles in the steel industry. It helps in producing a flat surface with a smooth finish for further use. Surface grinding falls under grinding operations and is the most common practice under the grinding umbrella the steel profilers nowadays offer.

The finishing process involved in lumsden grinders uses a rotating head of segments that helps in smoothing the surface of steel plates eventually giving them a more refined look to attain a certain desired surface thickness for further purposeful functionality. Many steel profilers offer their clients grinding services, but not many offer this service when it comes to big industrial requirements, as the ordered size of steel plates and profiles is not compatible with the grinding machines that they own.

There are different types of lumsden grinders that provide desired finishes of the clients.

Rotary Lumsden Grinders – use segments (approximately 12-18) to remove excess material and grind on a circular magnetic table. Commercial thickness tolerances are +/-0.25 millimetre. These machines come in sizes from 24 inch (610mm) to 135 inch (3429mm).

Reciprocal Lumsden grinders – the same as above but a long rectangular table, rather than a circular table.

Only a few steel profilers in the UK are ISO certified and provide high quality lumsden grinder services to their clients. The main motive behind grinding is to get a better quality of finished product in terms of:

• Appearance of the steel plates and profiles
• Customer desired thickness
• Improved flatness on original material