MXS66 TROWEL, FINISH 16" x 4" | High-grade carbon spring steel blade. Blade cross-ground to better hold its proper shape. Aluminum alloy mounting is fully heat-treated for strength, polish and machine finished to ensure an ideal handle-to-post fit. Exclusive diamond shank fits ideally into a square hole of the hardwood handle. Hardened steel rivets are used to attach the blade to the mounting. Each rivet is properly sized and computer fit for added strength. Since they are not welded, there is no embrittlement problem causing premature breaking.