Colonial silversmiths used many of the techniques developed by those in Europe. Casting was frequently the first step in manufacturing silver pieces, as silver workers would melt down sterling silver into easily manageable ingots. Occasionally, they would create small components (e.g. teapot legs) by casting silver into iron or graphite molds, but it was rare for an entire piece to be fabricated via casting. More commonly, a silversmith would forge an ingot into the desired shape, often hammering the thinned silver against specially shaped dies to "mass produce" simple shapes like the oval end of a spoon. The hammering occurred at room temperature, and, like any cold forming process, caused work hardening of the silver, which become increasingly brittle and difficult to shape. To restore the workability, the silversmith would anneal the piece—that is, heat it to a dull red and then quench it in water—to relieve the stresses in the material and return it to a more ductile state. Hammering required more time than all other silver manufacturing processes, and therefore accounted for the majority of labor costs. Silversmiths would then seam parts together to create complex and artistic items, sealing the gaps with a solder of 80 wt% silver and 20 wt% bronze. Finally, they would file and polish their work to remove all seams, finishing off with engraving and stamping the smith's mark.