The manufacturing Process of seamless steel tubes in china

China is known for its vast manufacturing capabilities and its ability to produce a wide range of products. One industry in which China has made significant strides is the production of seamless steel tubes. These tubes are widely used in various industries, including Oil and gas, automotive, and construction. In this article, we will explore the manufacturing process of seamless steel tubes in China.
Labels | Outside Diameter (d/mm) | T&C (kg/m) | wall thickness (t/mm) | Type of end-finish | |||||||
1 | 2 | J55/ K55 | M65 | L80/ R95 | N80-1/Q | C90/T95 | P110 | Q125 | |||
4-1/2 | 9.50 | 114.30 | 14.14 | 5.21 | PS | PS | – | – | – | – | – |
10.50 | 114.30 | 15.63 | 5.69 | PSB | PSB | – | – | – | – | – | |
11.60 | 114.30 | 17.26 | 6.35 | PSLB | PLB | PLB | PLB | PLB | PLB | – | |
13.50 | 114.30 | 20.09 | 7.37 | – | PLB | PLB | PLB | PLB | PLB | – | |
15.10 | 114.30 | 22.47 | 8.56 | – | – | – | – | – | PLB | PLB | |
5 | 11.50 | 127.00 | 17.11 | 5.59 | PS | PS | – | – | – | – | – |
13.00 | 127.00 | 19.35 | 6.43 | PSLB | PSLB | – | – | – | – | – | |
15.00 | 127.00 | 22.32 | 7.52 | PSLB | PLB | SLB | PLB | PLB | PLB | ||
18.00 | 127.00 | 26.79 | 9.19 | – | PLB | SLB | PLB | PLB | PLB | PLB | |
21.40 | 127.00 | 31.85 | 11.10 | – | PLB | PLB | PLB | PLB | PLB | PLB | |
23.20 | 127.00 | 34.53 | 12.14 | – | – | PLB | PLB | PLB | PLB | PLB | |
24.10 | 127.00 | 35.87 | 12.70 | – | – | PLB | PLB | PLB | PLB | PLB | |
5-1/2 | 14.00 | 139.70 | 20.83 | 6.20 | PS | PS | – | – | – | – | – |
15.50 | 139.70 | 23.07 | 6.98 | PSLB | PSLB | – | – | – | – | – | |
17.00 | 139.70 | 25.30 | 7.72 | PSLB | PLB | PLB | PLB | PLB | PLB | – | |
20.00 | 139.70 | 29.76 | 9.17 | – | PLB | PLB | PLB | PLB | PLB | – | |
23.00 | 139.70 | 34.23 | 10.54 | – | PLB | PLB | PLB | PLB | PLB | PLB | |
26.80 | 139.70 | 39.88 | 12.70 | – | – | – | – | P | – | – | |
29.70 | 139.70 | 44.20 | 14.27 | – | – | – | – | P | – | – | |
32.60 | 139.70 | 48.52 | 15.88 | – | – | – | – | P | – | – | |
35.30 | 139.70 | 52.53 | 17.45 | – | – | – | – | P | – | – | |
38.00 | 139.70 | 56.55 | 19.05 | – | – | – | – | P | – | – | |
40.50 | 139.70 | 60.27 | 20.62 | – | – | – | – | P | – | – | |
43.10 | 139.70 | 64.14 | 22.22 | – | – | – | – | P | – | – | |
6-5/8 | 20.00 | 168.28 | 29.76 | 7.32 | PSLB | PSLB | – | – | – | – | – |
24.00 | 168.28 | 35.72 | 8.94 | PSLB | PLB | PLB | PLB | PLB | PLB | – | |
28.00 | 168.28 | 41.67 | 10.59 | – | PLB | PLB | PLB | PLB | PLB | – | |
32.00 | 168.28 | 47.62 | 12.06 | – | – | PLB | PLB | PLB | PLB | PLB | |
7 | 17.00 | 177.80 | 25.30 | 5.87 | – | – | – | – | – | – | – |
20.00 | 177.80 | 29.76 | 6.91 | PS | PS | – | – | – | – | – | |
23.00 | 177.80 | 34.23 | 8.05 | PSLB | PLB | PLB | PLB | PLB | – | – | |
26.00 | 177.80 | 38.69 | 9.19 | – | PLB | PLB | PLB | PLB | PLB | – | |
29.00 | 177.80 | 43.16 | 10.36 | – | PLB | PLB | PLB | PLB | PLB | – | |
32.00 | 177.80 | 47.62 | 11.51 | – | PLB | PLB | PLB | PLB | PLB | – | |
35.00 | 177.80 | 52.09 | 12.65 | – | – | PLB | PLB | PLB | PLB | PLB | |
38.00 | 177.80 | 56.55 | 13.72 | – | – | PLB | PLB | PLB | PLB | PLB | |
42.70 | 177.80 | 63.55 | 15.88 | – | – | – | – | P | – | – | |
46.40 | 177.80 | 69.05 | 17.45 | – | – | – | – | P | – | – | |
50.10 | 177.80 | 74.56 | 19.05 | – | – | – | – | P | – | – | |
53.60 | 177.80 | 79.77 | 20.62 | – | – | – | – | P | – | – | |
57.10 | 177.80 | 84.98 | 22.22 | – | – | – | – | P | – | – | |
7-5/8 | 24.00 | 193.68 | 35.72 | 7.62 | – | – | – | – | – | – | |
26.40 | 193.68 | 39.29 | 8.33 | PSLB | PSLB | PLB | PLB | PLB | – | – | |
29.70 | 193.68 | 44.20 | 9.52 | – | PLB | PLB | PLB | PLB | PLB | – | |
33.70 | 193.68 | 50.15 | 10.92 | – | PLB | PLB | PLB | PLB | PLB | – | |
39.00 | 193.68 | 58.04 | 12.70 | – | – | PLB | PLB | PLB | PLB | PLB | |
42.80 | 193.68 | 63.69 | 14.27 | – | – | PLB | PLB | PLB | PLB | PLB | |
45.30 | 193.68 | 67.42 | 15.11 | – | – | PLB | PLB | PLB | PLB | PLB | |
47.10 | 193.68 | 70.09 | 15.88 | – | – | PLB | PLB | PLB | PLB | PLB | |
51.20 | 193.68 | 76.20 | 17.45 | – | – | – | – | P | – | – | |
55.30 | 193.68 | 82.30 | 19.05 | – | – | – | – | P | – | – | |
7-3/4 | 46.10 | 196.85 | 68.61 | 15.11 | – | – | P | P | P | P | P |
8-5/8 | 24.00 | 219.08 | 35.72 | 6.71 | PS | PS | – | – | – | – | – |
28.00 | 219.08 | 41.67 | 7.72 | PS | – | – | – | – | – | ||
32.00 | 219.08 | 47.62 | 8.94 | PSLB | PSLB | – | – | – | – | – | |
36.00 | 219.08 | 53.58 | 10.16 | PSLB | PSLB | PLB | PLB | PLB | PLB | – | |
40.00 | 219.08 | 59.53 | 11.43 | – | PLB | PLB | PLB | PLB | PLB | – | |
44.00 | 219.08 | 65.48 | 12.70 | – | – | PLB | PLB | PLB | PLB | – | |
49.00 | 219.08 | 72.92 | 14.15 | – | – | PLB | PLB | PLB | PLB | PLB | |
9-5/8 | 32.30 | 244.48 | 48.07 | 7.92 | – | – | – | – | – | – | – |
36.00 | 244.48 | 53.58 | 8.94 | PSLB | PSLB | – | – | – | – | – | |
40.00 | 244.48 | 59.53 | 10.03 | PSLB | PSLB | PLB | PLB | PLB | – | – | |
43.50 | 244.48 | 64.74 | 11.05 | – | PLB | PLB | PLB | PLB | PLB | – | |
47.00 | 244.48 | 69.95 | 11.99 | – | PLB | PLB | PLB | PLB | PLB | PLB | |
53.50 | 244.48 | 79.62 | 13.84 | – | – | PLB | PLB | PLB | PLB | PLB | |
58.40 | 244.48 | 86.91 | 15.11 | – | – | PLB | PLB | PLB | PLB | PLB | |
59.40 | 244.48 | 88.40 | 15.47 | – | – | – | – | P | – | – | |
64.90 | 244.48 | 96.58 | 17.07 | – | – | – | – | P | – | – | |
70.30 | 244.48 | 104.62 | 18.64 | – | – | – | – | P | – | – | |
75.60 | 244.48 | 112.51 | 20.24 | – | – | – | – | P | – | – | |
10-3/4 | 32.75 | 273.05 | 48.74 | 7.09 | – | – | – | – | – | – | – |
40.50 | 273.05 | 60.27 | 8.89 | PSB | PSB | – | – | – | – | – | |
45.50 | 273.05 | 67.71 | 10.16 | PSB | PSB | – | – | – | – | – | |
51.00 | 273.05 | 75.90 | 11.43 | PSB | PSB | PSB | PSB | PSB | PSB | – | |
55.50 | 273.05 | 82.60 | 12.57 | – | PSB | PSB | PSB | PSB | PSB | – | |
60.70 | 273.05 | 90.33 | 13.84 | – | – | – | – | PSB | PSB | PSB | |
65.70 | 273.05 | 97.77 | 15.11 | – | – | – | – | PSB | PSB | PSB | |
73.20 | 273.05 | 108.94 | 17.07 | – | – | – | – | P | – | – | |
79.20 | 273.05 | 117.87 | 18.64 | – | – | – | – | P | – | – | |
85.30 | 273.05 | 126.94 | 20.24 | – | – | – | – | P | – | – | |
11-3/4 | 42.00 | 298.45 | 62.50 | 8.46 | – | – | – | – | – | – | – |
47.00 | 298.45 | 69.95 | 9.53 | PSB | PSB | – | – | – | – | – | |
54.00 | 298.45 | 80.36 | 11.05 | PSB | PSB | – | – | – | – | – | |
60.00 | 298.45 | 89.29 | 12.42 | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
65.00 | 298.45 | 96.73 | 13.56 | – | – | P | P | P | P | P | |
71.00 | 298.45 | 105.66 | 14.78 | – | – | P | P | P | P | P | |
13-3/8 | 48.00 | 339.72 | 71.43 | 8.38 | – | – | – | – | – | – | – |
54.50 | 339.72 | 81.11 | 9.65 | PSB | PSB | – | – | – | – | – | |
61.00 | 339.72 | 90.78 | 10.92 | PSB | PSB | – | – | – | – | – | |
68.00 | 339.72 | 101.20 | 12.19 | PSB | PSB | PSB | PSB | PSB | PSB | – | |
72.00 | 339.72 | 107.15 | 13.06 | – | – | PSB | PSB | PSB | PSB | PSB | |
16 | 65.00 | 406.40 | 96.73 | 9.53 | – | – | – | – | – | – | – |
75.00 | 406.40 | 111.62 | 11.13 | PSB | PSB | – | – | – | – | – | |
84.00 | 406.40 | 125.01 | 12.57 | PSB | PSB | – | – | – | – | – | |
109.00 | 406.40 | 162.21 | 16.66 | P | – | P | P | – | P | P | |
18-5/8 | 87.50 | 473.08 | 130.22 | 11.05 | PSB | PSB | – | – | – | – | – |
20 | 94.00 | 508.00 | 139.89 | 11.13 | PSLB | PSLB | – | – | – | – | – |
106.50 | 508.00 | 158.49 | 12.70 | PSLB | PSLB | – | – | – | – | – | |
133.00 | 508.00 | 197.93 | 16.13 | PSLB | – | – | – | – | – | – |
Item No | product name | standard | Steel grade | size(mm) | Application | |
1 | pressure fluid steel Pipe | astm a106 | Gr.A、Gr.B、Gr.C | OD:21.3-1220 | boiler,heat exchanger,medium low pipeline | |
ASTM A53 | Wall:2.0-100 | |||||
2 | casing,oil pipe,coupling | api5ct PSL1、 | group1:J55、 K55、N80、R95 | OD:26.7-762 | Steel tube for oil field | |
PSL2 PSL3 | group2:L80、 C90、T95 | Wall:2.87-40 | ||||
group3:P110 | ||||||
3 | pipeline transportation system | API5L | A、B、X42、X46、X52、X60、X65、X70、X80 | OD:26.7-1220 | oil and gas pipeline, refining equipment pipeline | |
PSL1 | Wall:2.87-100 | |||||
PSL2 | ||||||
4 | mechanical high precision seamless pipe | ASTM A519 | SAE1018、SAE1020、SAE1045、SAE1518、SAE1541、SAE4130、SAE4135、SAE4140、SAE8620、ST78、ST52、E215、E235、E355、E410、C35E、C45E、25CrMo4、42CrMo4 | OD:21.3-406 | high precision machined seamless tube,construction machine,automobile engine | |
EN10305-1 | Wall:2.0-40 | |||||
DIN2391 | ||||||
GB3639 | ||||||
5 | heat exchanger and condenser low carbon cold drawn seamless pipe | ASTM A179 | A179 | OD:6-76.2 | heat exchanger | |
Wall:1.0-20 | ||||||
6 | high pressure Carbon steel seamless boiler pipe | ASTM A192 | A192 | OD:12.7-177.8 | high pressure boiler tube | |
Wall:2.0-25.4 | ||||||
7 | boder,superheater unit medium carbon seamless steel pipe | ASTM A210 | A210A-1 | OD:12.7-127 | high pressure toiler and heat exchanger | |
A210-C | Wall:0.9-12.7 | |||||
8 | boiler,superheater unit femilic alloy steel pipe | astm a213 | T2、T11、T12、T22、T5、T5b、T5C | OD:6-127 | high pressure boiler,superheater unit, heat exchanger alloy steel tube | |
Wall:0.4-12 | ||||||
9 | seamless steel pipe for pressure purpose | EN10216-1 | 195GH、P235GH、P265GH、20MnNb6、16Mo3、13CrMo4-5 | OD:21.3-762 | pressure piping | |
EN10216-2 | Wall:2.0-40 | |||||
10 | gas cylinder seamless steel pipe | GB18248 | 37Mn、34Mn2V、30CrMo、35CrMo、34CrMo4、30CrMnSiA、STH11、STH12、STH21、STH22、STH31 | OD:76-356 | high pressure gas cylinder | |
JIS G3429 | Wall:2.5-6.0 | |||||
11 | the automotive axle pipe | YB/T 5035 | 45#、45Mn2、40MnB、40Cr | OD:76-121 | automobile application | |
Wall:7.0-28.5 |

Tensile and Hardness Requirements | |||||||||
Grade | Yield strength MPa | Tensile Strength | Hardness a,c | Specified Wall Thickness | Allowable Hardness Variation b | ||||
Type | Total Elongation Under Load | min MPa | max | ||||||
min | max | HRC | HBW | mm | HRC | ||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
H40 | — | 0.5 | 276 | 552 | 414 | — | — | — | — |
J55 | — | 0.5 | 379 | 552 | 517 | — | — | — | — |
K55 | — | 0.5 | 379 | 552 | 655 | — | — | — | — |
N80 | 1 | 0.5 | 552 | 758 | 689 | — | — | — | — |
N80 | Q | 0.5 | 552 | 758 | 689 | — | — | — | — |
R95 | — | 0.5 | 655 | 758 | 724 | — | — | — | — |
L80 L80 | 1 | 0.5 | 552 | 655 | 655 | 23 | 241 | — | — |
L80 | 9Cr 13Cr | 0.5 | 552 | 655 | 655 | 23 | 241 | — | — |
0.5 | 552 | 655 | 655 | 23 | 241 | — | — | ||
C90 | 1 | 0.5 | 621 | 724 | 689 | 25.4 | 255 | £12.70 | 3 |
12.71 to 19.04 | 4 | ||||||||
19.05 to 25.39 | 5 | ||||||||
³ 25.40 | 6 | ||||||||
T95 | 1 | 0.5 | 655 | 758 | 724 | 25.4 | 255 | £12.70 | 3 |
12.71 to 19.04 | 4 | ||||||||
19.05 to 25.39 | 5 | ||||||||
³ 25.40 | 6 | ||||||||
C110 | — | 0.7 | 758 | 828 | 793 | 30 | 286 | £12.70 | 3 |
12.71 to 19.04 | 4 | ||||||||
19.05 to 25.39 | 5 | ||||||||
³ 25.40 | 6 | ||||||||
P110 | — | 0.6 | 758 | 965 | 862 | — | — | — | — |
Q125 | 1 | 0.65 | 862 | 1034 | 931 | b | — | £12.70 | 3 |
12.71 to 19.04 19.05 | 4 | ||||||||
5 | |||||||||
a In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method. | |||||||||
b No hardness limits are specified, but the maximum variation is restricted as a manufacturing control in accordance with 7.8 and 7.9. | |||||||||
c For through-wall hardness tests of Grades L80 (all types), C90, T95 and C110, the requirements stated in HRC scale are for maximum mean hardness number. |
