Diamond working parts , Concave transition layer and welding layer. The working layer use a single grain size(fine particle) of diamond, can be used to cut granite(soft, medium, hard) and artificial plate. The inner concave transition layer contains no diamond, dividing the segment into two working area, which is similar to the short segment structure, can increase the blade sharpness. Besides, in cutting process, the transition layer can provide buffer and chip removal, and reduce the friction resistance between the blade side and stone, which can improve the sharpness of the blade. No diamond is included in the welding layer of the blade, ensuring the welding strength and cutting safety .