A、b類供應的(de)(de)(de)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)，如用(yong)(yong)(yong)(yong)(yong)于承受液(ye)體(ti)壓(ya)(ya)(ya)力，也(ye)要進行水(shui)壓(ya)(ya)(ya)(特指(zhi):壓(ya)(ya)(ya)強(qiang))試驗(yan)。精密(mi)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)是(shi)一種(zhong)通過冷(leng)軋或冷(leng)拔處理后的(de)(de)(de)高精密(mi)的(de)(de)(de)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)；全(quan)稱：冷(leng)軋或冷(leng)拔精密(mi)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)。由于精密(mi)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)內外壁無(wu)(wu)(wu)(wu)氧(yang)化層、承受高壓(ya)(ya)(ya)無(wu)(wu)(wu)(wu)泄漏(lou)、高精度(du)、高光潔度(du)、冷(leng)彎(wan)不變形、擴口、壓(ya)(ya)(ya)扁無(wu)(wu)(wu)(wu)裂縫(feng)(feng)(feng)等(deng)優點(dian)，所以主(zhu)要用(yong)(yong)(yong)(yong)(yong)來(lai)生產氣動或液(ye)壓(ya)(ya)(ya) 元(yuan)件的(de)(de)(de)產品，如氣缸(gang)或油缸(gang)，都是(shi)用(yong)(yong)(yong)(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)管(guan)(guan)(guan)(guan)。精密(mi)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)的(de)(de)(de)化學成分有碳C、硅Si、錳Mn、硫S、磷P、鉻Cr。3、專門用(yong)(yong)(yong)(yong)(yong)途的(de)(de)(de)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)管(guan)(guan)(guan)(guan)有鍋爐（Boilers）用(yong)(yong)(yong)(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)管(guan)(guan)(guan)(guan)、化工(gong)(gong)電力用(yong)(yong)(yong)(yong)(yong)，地(di)質(zhi)用(yong)(yong)(yong)(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)及(ji)石油用(yong)(yong)(yong)(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)管(guan)(guan)(guan)(guan)等(deng)多種(zhong)。 無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)具有中空截面，大量(liang)用(yong)(yong)(yong)(yong)(yong)作輸送流體(ti)的(de)(de)(de)管(guan)(guan)(guan)(guan)道(dao)(Conduit)，如輸送石油、天然(ran)(natural)氣、煤氣、水(shui)及(ji)某(mou)些固體(ti)物料(liao)(liao)的(de)(de)(de)管(guan)(guan)(guan)(guan)道(dao)等(deng)。鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)與圓鋼(gang)(gang)(gang)(gang)(gang)等(deng)實心鋼(gang)(gang)(gang)(gang)(gang)材(cai)相(xiang)比，在(zai)抗(kang)彎(wan)抗(kang)扭強(qiang)度(du)（strength)相(xiang)同時，重量(liang)較輕，是(shi)一種(zhong)經(jing)濟(Economy)截面鋼(gang)(gang)(gang)(gang)(gang)材(cai)。 廣泛用(yong)(yong)(yong)(yong)(yong)于制(zhi)造(zhì zào)結(jie)構(Structure)件和(he)機(ji)械（machinery）零件，如石油鉆桿、汽車(che)(auto)傳動軸(zhou)(傳動軸(zhou)組(zu)成:軸(zhou)管(guan)(guan)(guan)(guan)、伸縮套(tao)和(he)萬(wan)向節)、自行車(che)架以及(ji)建筑施工(gong)(gong)中用(yong)(yong)(yong)(yong)(yong)的(de)(de)(de)鋼(gang)(gang)(gang)(gang)(gang)腳手架等(deng)用(yong)(yong)(yong)(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)制(zhi)造環形零件，可提高材(cai)料(liao)(liao)利用(yong)(yong)(yong)(yong)(yong)率(lv)，簡化制(zhi)造工(gong)(gong)序，節約材(cai)料(liao)(liao)和(he)加工(gong)(gong)(Processing)工(gong)(gong)時，已廣泛用(yong)(yong)(yong)(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)來(lai)制(zhi)造。