Precision seamless steel pipe, precision hydraulic seamless steel pipe, cold-drawn precision seamless steel pipe, cold-rolled precision seamless steel pipe, high-precision seamless steel pipe, precision bright seamless steel pipe.
(1) Main varieties of steel pipes: DIN series high-precision precision bright seamless steel pipes, special steel pipes for hydraulic system, and special steel pipes for automobile manufacturing.
(2) Main standards: DIN2391, DIN2445, EN10305, DIN1629, DIN1630, ASTM A179
(3) Main material: ST35 (E235) ST37.4 ST45 (E255) ST52 (E355)
(4) Main delivery status: NBK (+N) GBK (+A) BK (+C) BKW (+LC) BKS (+SR)
(5) Main features: the inner and outer walls of the steel pipe have no oxide layer, no leakage under high pressure, high precision, high finish, no deformation during cold bending, no crack during flaring and flattening.
(6) Main applications: used in hydraulic system piping, automobile manufacturing piping, military industry, engineering machinery, railway locomotive, aerospace, ship, injection molding machine, die-casting machine, machine tool, diesel engine, petrochemical industry, power station, boiler equipment and other industries.

MaterialCSiMnPSCrNiCuMo ASTM 4119 GB 12CrMo0.08-0.150.17-0.370.4-0.70.0350.0350.4-0.70.30.30.4-0.55 JIS SCM415 GB15CrMo0.12-0.180.17-0.370.4-0.70.0350.0350.8-1.10.30.30.4-0.55 ASTM 4118 GB 20CrMo0.17-0.240.17-0.370.4-0.70.0350.0350.8-1.10.30.30.15-0.25 ASTM 4130 GB 30CrMo0.26-0.340.17-0.370.4-0.70.0350.0350.8-1.10.30.30.15-0.25 ASTM 4135 GB 35CrMo0.32-0.40.17-0.370.4-0.70.0350.0350.8-1.10.30.30.15-0.25 ASTM 4140  GB  42CrMo0.38-0.450.17-0.370.5-0.80.0350.0350.9-1.20.30.30.15-0.25 ASTM 4142  GB 42CrMnMo0.4-0.450.15-0.350.78-10.0350.040.8-1.10.250.350.15-0.25

MaterialDiameter of sample
d
mmHeat treatment or condition.Tensile strength
σ_b
Mpa Point of yield
σ_s
Mpa Ratio of elongation
δ
% Reduction of section
ψ
% hardness
HBW Shock absorption energy
KV2
J ASTM 4119 GB 12CrMod=30Quenching + tempering≥410≥265≥24≥60≤179≥110 JIS SCM415
GB 15CrMod=30Quenching + tempering≥440≥295≥22≥60≤179≥94 ASTM 4118
GB 20CrMod=15Quenching + tempering≥885≥685≥12≥50≤197≥78 ASTM 4130
GB 30CrMod=25Quenching + tempering≥930≥785≥12≥50≤229≥63 ASTM 4135
GB 35CrMod=25Quenching + tempering≥980≥835≥12≥45≤229≥63 ASTM 4140   
 GB  42CrMod=25Quenching + tempering≥1080≥930≥12≥45≤217≥63

Generally, the import volume of seamless pipe is large. The main importing countries are Germany and Japan. European countries such as Romania, Russia, Switzerland, France, Spain, the Czech Republic, Yugoslavia, Hungary and other countries have imported. There are also a small amount of imports from Argentina, Mexico and other countries in South America.
According to the different requirements of the consumer in China, there are more than 100 types of imported seamless pipes, including 15922mm, 1595mm and 15918mm. 114.38mm,114.310mm,114.313mm. The length is generally 5-8m or 4-7m. Mainly hot-rolled carbon structure and ST65. The minimum diameter of the inlet specification is 305 mm, and the maximum diameter is 47813 mm.
A small number of seamless pipes with small diameter and thin wall have been imported from France and Spain, such as 183mm, 223mm, 26.93mm, etc. Implement the general rules of Mannesmann Steel Pipe Plant in Germany.
Seamless pipes imported from Hungary and Japan often refer to DIN2448 and DIN1629.

Seamless pipes are widely used. Seamless pipes for general purposes are rolled by ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output, and are mainly used as pipes or structural parts for conveying fluid.
Supply is divided into three types according to different purposes: a. Supply according to chemical composition and mechanical properties; B. Supply according to mechanical properties; C. Supply according to hydraulic test. The steel pipes supplied according to category a and b shall also be subjected to hydraulic test if they are used to bear liquid pressure.
There are many kinds of seamless pipes for special purposes, such as boiler seamless pipes, geological seamless pipes and petroleum seamless pipes.