content_image/601172.jpg content_image/601174.jpg content_image/601173.jpg
3. Using a soft-faced shrinking mallet, start hammering near the center and work the flange down gradually toward both ends. The flange tends to buckle at the bend because the material is made to occupy less space. Work the material into several small buckles instead of one large one and work each buckle out gradually by hammering lightly and gradually compressing the material in each buckle. The use of a small hardwood wedge block aids in working out the buckles. [Figure 4-152] 

4. Planish the flange after it is flattened against the form block and remove small irregularities. If the form blocks are made of hardwood, use a metal planishing hammer. If the forms are made of metal, use a soft-faced mallet. Trim the excess material away and file and polish. 

## Stretching 

To form a flanged angle by stretching, use the same forming blocks, wooden wedge block, and mallet as used in the shrinking process and proceed as follows: 

1. Cut the material to size (allowing for trim), determine bend allowance for a 90° bend, and round off the edge of the block to conform to the desired radius of bend. 

2. Clamp the material in the form blocks. [Figure 4-153] 

3. Using a soft-faced stretching mallet, start hammering near the ends and work the flange down smoothly and gradually to prevent cracking and splitting. Planish the flange and angle as described in the previous procedure, and trim and smooth the edges, if necessary. 

## Curved Flanged Parts 

Curved flanged parts are usually hand formed with a concave flange, the inside edge, and a convex flange, the outside edge. 

<img src='content_image/601172.jpg'>

<img src='content_image/601174.jpg'>

The concave flange is formed by stretching, while the convex flange is formed by shrinking. Such parts are shaped with the aid of hardwood or metal forming blocks. [Figure 4-154] These blocks are made in pairs and are 

<img src='content_image/601173.jpg'>

