This rock solid, 2 kilo block of dead flat of 10mm thick float glass is the ideal substrate for use with sheet abrasives for scary sharpening. The lapping plate is the same width as 3M lapping film sheets so that both ends can be used for flattening the backs of blades, and long enough to accommodate several grades.
We had initially looked at a thinner sheet of toughened float glass but then discovered that some of the flatness is lost during the toughening process. Consequently this glass is not toughened and will produce shards if it breaks, it is however, very, very flat.
360mm (14.1") x 220mm (8.6") x 10mm (0.4")