Abstract: An apparatus for stretching sheet-metal strips includes several bending heads removably mounted between pairs of tension rollers, each bending head comprising a slender deflecting roller journaled in two end bearings and supported by heavier, shorter back-up rollers arrayed in two closely adjoining rows. The back-up rollers of each row have stud shafts cradled in V-shaped notches of a multiplicity of parallel webs transverse to their axis, the webs being integral with a common beam swingably mounted on a supporting frame. Oppositely notched retaining yokes are detachably secured to the webs to hold the roller shafts in place and to complement the notches to diamond-shaped seats for these shafts. The bearing notches of all the webs are simultaneously machined and/or trued by the same tool sweeping thereacross.