, ▁whereas ▁hot - rolled ▁shapes ▁typically ▁exhib it ▁tap ering ▁or ▁fil lets . ▁Cold - formed ▁steel ▁allowed ▁for ▁shapes ▁which ▁differ ed ▁greatly ▁from ▁the ▁classical ▁hot - rolled ▁shapes . ▁The ▁material ▁was ▁easily ▁work able ; ▁it ▁could ▁be ▁de formed ▁into ▁many ▁possible ▁shapes . ▁Even ▁a ▁small ▁change ▁in ▁the ▁geometry ▁created ▁significant ▁changes ▁in ▁the ▁strength ▁characteristics ▁of ▁the ▁section . ▁It ▁was ▁necessary ▁to ▁establish ▁some ▁minimum ▁requirements ▁and ▁laws ▁to ▁control ▁the ▁bu ck ling ▁and ▁strength ▁characteristics . ▁Also ▁it ▁was ▁observed ▁that ▁the ▁thin ▁walls ▁under w ent ▁local ▁bu ck ling ▁under ▁small ▁loads ▁in ▁some ▁sections ▁and ▁that ▁these ▁elements ▁were ▁then ▁capable ▁of ▁carrying ▁higher ▁loads ▁even ▁after ▁local ▁bu ck ling ▁of ▁the ▁members . ▁ ▁In ▁the ▁United ▁States , ▁the ▁first ▁edition ▁of ▁the ▁Spec ification ▁for ▁the ▁Design ▁of ▁Light ▁G age ▁Ste el ▁Struct ural ▁M embers ▁was ▁published ▁by ▁the ▁American ▁Iron ▁and ▁Ste el ▁Institute ▁( A IS I ) ▁in ▁ 1 9 4 6 ▁( A IS I , ▁ 1 9 4 6 ). ▁As ▁a ▁result ▁of ▁this ▁work , ▁George ▁Winter ▁is ▁now ▁considered ▁the ▁grand father ▁of ▁cold - formed ▁steel ▁design . ▁ ▁The ▁AS D ▁Spec ification ▁was ▁subsequently ▁re vised ▁in ▁ 1 9 5 6 , ▁ 1 9 6 0 , ▁ 1 9 6 2 , ▁ 1 9 6 8 , ▁ 1 9 8 0 , ▁and