CB for Corrugated Back
WH for Williams & Hussey, Shop Fox W1693, W1739 and W1812 Bridgewood 704, Grizzly G0552, G0488 SB for a set of 3 knives, 1/4" thick, smooth steel for Grizzly G1037, G0477, Belsaw, Powermatic 15 and similar machines. SB1 for a single 1/4" thick knife with Gibs and counter weights for Foley-Belsaw and similar machines.