凡是(shi)(shi)兩端開(kai)口(kou)并具(ju)(ju)有中空斷(duan)面(mian)(mian)(mian)，而且(qie)其長(chang)度(du)與斷(duan)面(mian)(mian)(mian)周長(chang)之(zhi)比(bi)較(jiao)大的(de)(de)(de)鋼(gang)(gang)(gang)材(cai)(cai)，都(dou)可以(yi)稱(cheng)為(wei)鋼(gang)(gang)(gang)管(guan)(guan)。當長(chang)度(du)與斷(duan)面(mian)(mian)(mian)周長(chang)之(zhi)比(bi)較(jiao)小時(shi)，可稱(cheng)為(wei)管(guan)(guan)段或管(guan)(guan)形配(pei)件(jian)，它們都(dou)屬于管(guan)(guan)材(cai)(cai)產品的(de)(de)(de)范疇。鋼(gang)(gang)(gang)管(guan)(guan)是(shi)(shi)一(yi)種(zhong)(zhong)經(jing)濟斷(duan)面(mian)(mian)(mian)鋼(gang)(gang)(gang)材(cai)(cai)，是(shi)(shi)鋼(gang)(gang)(gang)鐵(tie)工(gong)(gong)(gong)業(ye)中的(de)(de)(de)一(yi)項重(zhong)(zhong)要產品，通常占全部(bu)鋼(gang)(gang)(gang)材(cai)(cai)總(zong)量(liang)(liang)的(de)(de)(de)8%~16%左右，它在(zai)國民經(jing)濟中的(de)(de)(de)應用范圍極為(wei)廣泛。由于鋼(gang)(gang)(gang)管(guan)(guan)具(ju)(ju)有空心斷(duan)面(mian)(mian)(mian)，因而最(zui)適合作(zuo)液體、氣體和固體的(de)(de)(de)輸送管(guan)(guan)道；同時(shi)與相同重(zhong)(zhong)量(liang)(liang)的(de)(de)(de)圓鋼(gang)(gang)(gang)比(bi)較(jiao)，鋼(gang)(gang)(gang)管(guan)(guan)的(de)(de)(de)斷(duan)面(mian)(mian)(mian)系數大、抗(kang)彎抗(kang)扭強度(du)大，所以(yi)也成為(wei)各種(zhong)(zhong)機械和建(jian)筑結構上的(de)(de)(de)重(zhong)(zhong)要材(cai)(cai)料。用鋼(gang)(gang)(gang)管(guan)(guan)制(zhi)(zhi)成的(de)(de)(de)結構和部(bu)件(jian)，在(zai)重(zhong)(zhong)量(liang)(liang)相等的(de)(de)(de)情況下，比(bi)實心零部(bu)件(jian)具(ju)(ju)有更大的(de)(de)(de)截(jie)面(mian)(mian)(mian)模數。所以(yi)，鋼(gang)(gang)(gang)管(guan)(guan)本身就是(shi)(shi)一(yi)種(zhong)(zhong)節約金屬的(de)(de)(de)經(jing)濟斷(duan)面(mian)(mian)(mian)鋼(gang)(gang)(gang)材(cai)(cai)，它是(shi)(shi)高(gao)效鋼(gang)(gang)(gang)材(cai)(cai)的(de)(de)(de)一(yi)個重(zhong)(zhong)要組(zu)成部(bu)分(fen)，尤其在(zai)石油鉆采、冶(ye)煉(lian)和輸送等行(xing)業(ye)需求較(jiao)大，其次地質鉆探、化工(gong)(gong)(gong)、建(jian)筑工(gong)(gong)(gong)業(ye)、機械工(gong)(gong)(gong)業(ye)、飛機和汽車制(zhi)(zhi)造以(yi)及鍋爐、醫療(liao)器械、家具(ju)(ju)和自行(xing)車制(zhi)(zhi)造等方(fang)面(mian)(mian)(mian)也都(dou)需要大量(liang)(liang)的(de)(de)(de)各種(zhong)(zhong)鋼(gang)(gang)(gang)管(guan)(guan)。近年來，隨著(zhu)原子能、火箭(jian)、導彈和航天工(gong)(gong)(gong)業(ye)等新技(ji)術的(de)(de)(de)發展，鋼(gang)(gang)(gang)管(guan)(guan)在(zai)國防工(gong)(gong)(gong)業(ye)、科學技(ji)術和經(jing)濟建(jian)設(she)中的(de)(de)(de)地位(wei)愈加重(zhong)(zhong)要。

  鋼管(guan)的種類繁多(duo)，用(yong)途(tu)不同，其技術要求各異，生產方法亦有(you)所不同。目前(qian)生產的鋼管(guan)外徑(jing)范圍0.1~4500mm、壁(bi)厚范圍0.01~250mm.為了區(qu)分(fen)其特(te)點(dian)，通(tong)常按如下(xia)的方法對鋼管(guan)進行分(fen)類。

1. 按生(sheng)產方式(shi)分類

  鋼(gang)管(guan)(guan)(guan)(guan)(guan)按生產方式分為(wei)無(wu)縫(feng)管(guan)(guan)(guan)(guan)(guan)和(he)焊管(guan)(guan)(guan)(guan)(guan)兩大類，無(wu)縫(feng)鋼(gang)管(guan)(guan)(guan)(guan)(guan)又可分為(wei)熱軋管(guan)(guan)(guan)(guan)(guan)，冷(leng)軋管(guan)(guan)(guan)(guan)(guan)、冷(leng)拔管(guan)(guan)(guan)(guan)(guan)和(he)擠壓(ya)管(guan)(guan)(guan)(guan)(guan)等(deng)，冷(leng)拔、冷(leng)軋是鋼(gang)管(guan)(guan)(guan)(guan)(guan)的二次加工；焊管(guan)(guan)(guan)(guan)(guan)分為(wei)直縫(feng)焊管(guan)(guan)(guan)(guan)(guan)和(he)螺(luo)旋焊管(guan)(guan)(guan)(guan)(guan)等(deng)。

2. 按鋼管(guan)的斷面形狀分(fen)類

  鋼管(guan)按橫斷面(mian)(mian)形狀可分為圓(yuan)(yuan)(yuan)管(guan)和異形管(guan)。異形管(guan)有矩形管(guan)、菱形管(guan)、橢圓(yuan)(yuan)(yuan)管(guan)、六方管(guan)、八方管(guan)以(yi)及(ji)各(ge)種(zhong)斷面(mian)(mian)不對稱管(guan)等。異形管(guan)廣泛用于(yu)各(ge)種(zhong)結構件、工具(ju)和機械零部(bu)件。與圓(yuan)(yuan)(yuan)管(guan)相比，異形管(guan)一般都有較大(da)的慣性(xing)矩和截面(mian)(mian)模數，有較大(da)的抗彎、抗扭能力，可以(yi)大(da)大(da)減輕結構重量，節約鋼材。

  鋼管(guan)(guan)按(an)縱斷(duan)(duan)面(mian)(mian)形(xing)狀可分為等(deng)斷(duan)(duan)面(mian)(mian)管(guan)(guan)和變斷(duan)(duan)面(mian)(mian)管(guan)(guan)。變斷(duan)(duan)面(mian)(mian)管(guan)(guan)有錐形(xing)管(guan)(guan)、階梯形(xing)管(guan)(guan)和周期斷(duan)(duan)面(mian)(mian)管(guan)(guan)等(deng)。

3. 按鋼管的材質分類

  鋼管按材質分為普通碳素鋼管、優質碳素結構鋼管、合金結構管、合金鋼管、軸承鋼管、不銹鋼(gang)管(guan)以及為節省貴重金屬和滿足特殊要求的雙金屬復合管、鍍層和涂層管等。

4. 按管端形狀分類

  鋼管(guan)根據管(guan)端狀態(tai)可分(fen)(fen)為(wei)光管(guan)和車(che)(che)絲(si)管(guan)（帶(dai)螺(luo)(luo)紋(wen)(wen)(wen)鋼管(guan)）。車(che)(che)絲(si)管(guan)又可分(fen)(fen)為(wei)普通(tong)車(che)(che)絲(si)管(guan)（輸(shu)送水(shui)、煤氣等(deng)低壓用(yong)管(guan)，采(cai)用(yong)普通(tong)圓柱或圓錐管(guan)螺(luo)(luo)紋(wen)(wen)(wen)連(lian)(lian)接(jie)）和特殊螺(luo)(luo)紋(wen)(wen)(wen)管(guan)（石油、地質鉆(zhan)探用(yong)管(guan)，對(dui)于重要的(de)車(che)(che)絲(si)管(guan)，采(cai)用(yong)特殊螺(luo)(luo)紋(wen)(wen)(wen)連(lian)(lian)接(jie)），對(dui)一些特殊用(yong)管(guan)，為(wei)彌補螺(luo)(luo)紋(wen)(wen)(wen)對(dui)管(guan)端強(qiang)度的(de)影響，通(tong)常在(zai)車(che)(che)絲(si)前先進(jin)行管(guan)端加(jia)厚（內加(jia)厚、外加(jia)厚或內外加(jia)厚）。

5. 按外徑D和壁厚S之比（D/S)分類

  按(an)外徑D和壁(bi)(bi)厚(hou)S之比的不同將鋼管(guan)(guan)分為特厚(hou)管(guan)(guan)（D/S≤10)、厚(hou)壁(bi)(bi)管(guan)(guan)（D/S=10~20)、薄壁(bi)(bi)管(guan)(guan)（D/S=20~40)和極(ji)薄壁(bi)(bi)管(guan)(guan)（D/S≥40)。

6. 按(an)用(yong)途(tu)分(fen)類

  按用途(tu)可分為油井管(guan)(guan)(guan)(guan)（套管(guan)(guan)(guan)(guan)、油管(guan)(guan)(guan)(guan)及(ji)鉆桿(gan)等）、管(guan)(guan)(guan)(guan)線管(guan)(guan)(guan)(guan)、鍋爐管(guan)(guan)(guan)(guan)、機械結(jie)構管(guan)(guan)(guan)(guan)、液壓支柱管(guan)(guan)(guan)(guan)、氣瓶(ping)管(guan)(guan)(guan)(guan)、地(di)質管(guan)(guan)(guan)(guan)、化工用管(guan)(guan)(guan)(guan)（高壓化肥管(guan)(guan)(guan)(guan)、石油裂化管(guan)(guan)(guan)(guan)）和船舶用管(guan)(guan)(guan)(guan)等。