Bon Tools Keystone Forged Masonry Trowels are forged from a single piece of specially formulated carbon steel. The blade has been heat tempered for uniform hardness. This trowel has a stronger uniform grain to ensure the blade will not weaken or crack. From the invention of masonry guides over 60 years ago to the launching of our Keystone Forged Brick Trowels this year, Bon is committed to the development and improvement of tools for professional contractors and do-it-yourselfers alike. We put our trusted name to every product we sell.