Tool Wrap What is Precision Brand Tool Wrap? Tool Wrap is a Stainless Steel .002 thick foil. It is used for the surface protection of tools, dies and other parts during the hardening process by preventing decarburization (scaling). Is Tool Wrap available in different materials? Yes, standard Tool Wrap material is Type 321 Stainless Steel and this material will work in temperatures up to 2000 degrees F. We also offer a Type 309 Stainless Steel High-Temp material which works in temperatures up to 2240 degrees F. Who and where would Tool Wrap be used? There are numerous Tool Wrap uses found in many manufacturing plants and processes all over. Professionals who might use Tool Wrap would be tool and die makers, mold makers, machinists, and various maintenance personnel, just to name a few. Does Tool Wrap come in different thicknesses? Yes, other thicknesses are available in 309 and 321 Stainless Steel as a special order. How is Tool Wrap used? It is used in the heat treating process when a controlled vacuum furnace is not available. It saves time by allowing the hardening process to be done on the premises, without time lost due to parts being sent out for heat treatment. The tool, die or part to be heat treated is placed in an envelope formed by folding a sheet of Tool Wrap in half and carefully sealing the open ends of the envelope. This Tool Wrap envelope locks out the air and imitates the results which could be obtained from a vacuum furnace. Must the Tool Wrap package be air tight throughout the entire heating & hardening process? Usually, if the Tool Wrap envelope is not airtight, the heat draws in excess oxygen which causes pitting and scaling on the surface of your part. However, if it is an odd shaped piece, you may need a vent during the pre-heat process. It is also important to note that there is no difference in uniformity of hardness between loosely or tightly wrapped pieces. When is venting in the Tool Wrap envelope necessary? A sealed Tool Wrap envelope normally expands and contracts during heating and cooling due to entrapped air. With a particularly large or odd shaped tool, a large amount of entrapped air may strain the foil sufficiently for the tool, die or part to pierce through the Tool Wrap. This usually occurs during the cooling process and, therefore, is not generally a serious problem but can be completely eliminated by a simple vent. A vent can be created by preparing your Tool Wrap envelope the normal way and allow one corner to be open about 1/4 inch. Load the envelope into the hot furnace ensuring the vent remains open. The entrapped air will escape through the vent as the envelope heats, thus eliminating strains from pressure build-up during the heating cycle. As soon as the envelope becomes hot, seal the vent corner by folding it over with a pair of tongs. The envelope is then allowed to remain in the furnace until the heating cycle is completed. The venting procedure also reduces strains during cooling resulting from the rapid collapse of an expanded package. How much Tool Wrap is necessary? You should cut a piece of Tool Wrap from the roll large enough to cover the complete tool, die or part twice (top and bottom) with the allowance for over lapping by at least 3 inches all around.