... ST37-2,ST35-8),20#(ST42,ST45-4/8),45#(DIN CK45),16mn(ST52.4) etc.b. JIS Standard10#(STPG38, ... etc. seamless pipe for low and medium pressure boiler,high prssure boiler,ship-building ,petroleum cracking,chemical fertilizer equipment ... To withstand high pressure without cracking 4. Cold is not deformed5. High-precision high-quality finish high cleanliness astm structural seamless steel pipe 4 inch sch40