Stratening and Flattening
Any process applied to flat rolled products to eliminate any general or local curvature, either with respect to flatness or edgewise curvature.
1) Roll Flattening - The process of flattening a product by a machine with a number of small cylindrical rolls so positioned as to repeatedly flex the product and thus remove certain irregularities in shape. Roll flattening practically eliminates longitudinal curl, burr, and dish. It reduces edgewise curvature of narrow strip. This operation reduces buckles, but is relatively ineffective in eliminating wavy edges, ripples, and twist. Roll flattening is ordinarily applied to a Flat Rolled Product within the approximate range 0.010" to 0.125" thick and in widths to about 48", and is particularly effective on annealed tempers, but is progressively less effective with increase in degree of rolled temper.
2) Stretcher Straightening, (Patent Leveling) - Applicable to Flat Straight Lengths. A process which simultaneously flattens and straightens a product by longitudinally stretching it beyond its elastic limit. This process practically removes buckles, ripples, wavy edges, twist, and edgewise curvature, is partially effective in removing longitudinal curl but is ineffective in removal of crown, dish, and burr. It is commonly applied to flat rolled products within the approximate size range of 3" to 48" wide and 0.012" to 0.050" thick. It is particularly effective on all annealed tempers and on rolled tempers up to Half Hard.