Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. Name __________________________________ Date _____________ Class _____________ 231 Zivica Kerkez/Shutterstock.com UNIT 22 Bending Metal Key Terms fl at-out length Introduction You will often be called on to bend metal as part of your job in a welding shop. When a piece of metal is permanently bent, its fl at-out length is changed. Flat-out length is the original length of a piece of metal that has been permanently bent, shaped, or formed. Because of this dimensional change, you must be able to calculate fl at-out lengths of metal objects that will be formed by bending. Most of the bends you will encounter can be grouped into the following types: ▪ 90° sharp corner bend ▪ Cylinder ▪ Half cylinder ▪ Quarter cylinder A short explanation of the effects of bending may help you understand the calculations of bending. Why does permanent bending affect the length of a piece of metal? The primary reason is that metal can be stretched and compressed. For example, when metal is bent, the metal at the bend is compressed on the inside of the corner and stretched on the outside of the corner. The bent piece of metal now has two different lengths—the inside length and the outside length. 90° Sharp Corner Bend A 90° sharp corner bend is the most common bend you will encounter. Drawings for bent metal parts can be dimensioned in two different ways. Either the inside lengths or the outside lengths can be dimensioned. The following illustrations show both methods. When given the job of bending a piece of metal, you will need to know either the inside dimensions or the outside dimensions. You will also need to know the thickness of the metal. With this information, you can calculate the fl at-out length. Select the icons to access Drill and Practice activities. Ch05.indd 231 5/3/2019 12:47:14 PM