... .9,JIS,DIN,GB,GOST,KB6. Surface treatment: black paint,vanish paint,rust-proof oil,hot galv7. Application:Prtroleum, chemical, power, gas,metallurgy ... .9,JIS,DIN,GB,GOST,KB6. Surface treatment: black paint,vanish paint,rust-proof oil,hot galv7. Application:Prtroleum, chemical, power, gas,metallurgy ...