弯曲度：工字钢高度小于或等于400MM时，每米弯曲度不得大于1.5MM，总弯曲度不得大于总长度的0.15%。高度大于400MM时，每米弯曲度不得大于1.0MM，总弯曲度不得大于总长度的0.1%。Bendingdegree:whentheheightoftheI-steelislessthanorequalto400MM,thebendingdegreeofeachmetermustnotbemorethan1.5MM,andthetotalbendingdegreeshouldnotbemorethan0.15%ofthetotallength.Whentheheightisgreaterthan400MM,thebendingdegreeofeachmetermustnotbemorethan1.0MM,andthetotalbendingdegreeshouldnotbemorethan0.1%ofthetotallength.工字型钢不论是普通型还是轻型的，由于截面尺寸均相对较高、较窄，故对截面两个主袖的惯性矩相差较大，因此，一般仅能直接用于在其腹板平面内受弯的构件或将其组成格构式受力构件。I-steelwhetherordinaryorlight,becausethesectionsizearerelativelyhighandnarrow,sothemomentofinertiaofthemainsecti***ofthetwosleeveislarge,therefore,generallyonlycanbedirectlyusedinthewebplanebendingmemberortheoflatticestresscomponents.H型钢是一种断面力学性能较工字钢优良的经济型断面钢材，因其断面的形状与英文字母“H”相同而得名。热轧H型钢的翼缘比工字钢宽、侧向刚度大、抗弯能力强。同等规格下H型钢理重较工字钢轻。HsteelisakindofeconomicalsectionsteelwithbettersectionmechanicalpropertiesthanthatofI-steel.BecausetheshapeofthesectionisthesameasthatoftheEnglishletterH.TheflangeofhotrolledHsteeliswiderthanthatofI-steel,largelateralstiffnessandstrongbendingresistance.Underthesamespecification,theweightofHsteelislighterthanthatofI-steel.)