Heaving mallet. Lignum vitae head, brass handle. Rigger's tool. Heaving mallets are used to apply force via leverage when hauling taught strands while splicing natural fibre or man made cordage, usually in combination with a heaving board, for tightening seizings (as opposed to servings) or any other use for tightening small cordage. Usually Brass handle with Lignum head (fully round). Different sizes available. In RN use, for riggers and seaman.