A corrugated cavity featured in some heart-shaped bend dies to force the wrinkling of the inside radius of the tube bend into a regular pattern. In the past the wrinkle control was used in the production of aftermarket automotive exhaust systems. However, that has declined because of the increased rate of corrosion failure and impeded exhaust flow that resulted from products with controlled wrinkles instead of the smooth surfaces of mandrel-bent products.
wrinkle control cavity
by builtbyRVWS | Jul 3, 2017