VACUUM BRAZED DIAMOND BLADES are manufactured by welding synthetic diamond particles to the outside edge of the circular saw blade in a vacuum brazing furnace. All of the diamond particles are on the exterior cutting edge of the blade, with no bond-diamond segments like other blades. Vacuum brazed blades will usually cut a wide variety of materials including concrete, masonry, steel, various irons, plastic, tile, wood and glass. They are also used to cut rail lines. The Fire Brigade, and other Emergency Services, will use them on ''rescue'' saw, so they are often called rescue blades.They perform well in dry applications, but the blade will last longer if water is used with them.