Design For Manufacturability – Sheet Metal Guidelines Bends For the ease of manufacturing, multiple bends on the same plane should occur in the same direction. Specification for sintered soft magnetic materials EN 10336: Continuously hot-dip coated and electrolytically coated strip and sheet of multiphase steels for cold forming EN 10340: Steel castings for structural uses EN 10341 The minumum flange length is based on the die used to bend. Linear tolerances should be held as loose as possible. Tight tolerances raise the cost of manufacturing significantly. SHEET METAL FABRICATION STANDARDS . Bends are the most typical feature of sheet metal parts and can be formed by a variety of methods and machines which negate the absolute need for some of the below tips. Sheet metal shops can bend to around +/-.015" accuracy. Various types of materials are available on earth. Each material has its own advantages, limitations and applications. However for typical parts meant to be cost effective and easily produced the following tips should be useful. Tolerances of +/- .010 should be considered minimum. Continuously hot-dip coated strip and sheet of low carbon steels for cold forming EN 10331: Magnetic materials. Practical tolerances vary according to the design requirements. 558 Federal Road, Brookfield, CT 06804 O. Avoid large sheet metal parts with small bent flanges. To ensure a precise manufacturing process and a quality product, most custom metal fabrication vendors are in compliance with the International Organization for Standardization (ISO), a body of representatives from industries around the world who establish, publish and distribute regulatory guidelines.. Sheet metal material selection is an iterative process. If you tell them to do +/-.005", they are either going to ingore your tolerances, or they are going to … Tolerances: Sheet metal tolerances should not be tighter than necessary to make the part functional. In low carbon steel sheet metal, the minimum radius of a bend should be one- After the selection of a material it should be validated and tested according to the requirements. The first edition of SMACNA’s Residential Sheet Metal Guidelines offers contractors, designers, builders and homeowners a source of expert information on the proper fabrication and installation of exterior sheet metal in residential buildings.