Hydraulics Steel Tubes

free quote now

Hydraulics steel tube is designed to convey liquid fluids to among hydraulics components, fittings, valves, flanges, and other tools. It is made of material E355 (ST 52.4) or E235 (ST 37.4). These two grades have different chemical composition. This helps to control the working pressure. 

Hydraulic tube is made according to DIN 2391/C (DIN EN 10305-1) or DIN 2445/2 (DIN EN 10305-4) standards and it is available in millimeters, inches outer diameter, and inches nominal bore size.

Size	4mm to 190mm outer diameter
Material Specifications	E355 (ST52.4) ​E235 (ST37.4)
Dimension Specifications ​	DIN 2391/C (DIN EN 10305-1) DIN 2445/2 (DIN EN 10305-4)
Finishing	NBK (Phosphate and Normalized)

CATALOGUE :

Hydraulics Steel Tubes

---

What are Hydraulics Steel Tube Specification

​1. What is hydraulics steel tube?

EN 10305-4 Hydraulic Steel Tubes

The hydraulic tube is cylinder-like shaped tubing device that when attach to hydraulic systems, allow for the passage of fluids within and among components. The tube standard specifies dimensions for cold drawn finishing and ​seamless precision steel tubes. Cold drawn process provides the tube with close dimensional tolerances, increase material strength and enhanced machinability. Therefore, hydraulics steel tubes are suitable in high performance piping system application. 

They typically have a length of approximately 6 meter long. To order tubes, user has to measure the tube outside diameter and inside diameter. Where the wall thickness is of significance, the tubes may ordered in terms of outside diameter and wall thickness or inside diameter and wall thickness. ​

​​​2. What is the material of hydraulics steel tube?

There are two type of material grade, ST52.4 and ST37.4. ST52.4 is high tensile strength tube means it has higher permissible working pressures by reduced tube wall thickness, and leading to reduced system overall weight. Please refer to chemical composition for ST52.4 and ST37.4 tube material: ​

1" Nominal Bore x Schedule 80 Hydraulic Steel Tubes

Chemical Composition (%)	Carbon (C)	​Silicon (Si)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)
​E355 (ST52.4)	​⩽ 0.22	⩽ 0.55	⩽ 1.6	⩽ 0.045	⩽ 0.045
E235 (ST37.4) ​	⩽ 0.17	​⩽ 0.35	⩽ 1.2 ​	⩽ 0.045	​⩽ 0.045

ST37.4 and ST52.4 are two different grades of steel with variations in their chemical composition. ST37.4 has a maximum carbon content of 0.17%, whereas ST52.4 has a maximum carbon content of 0.22%. The higher carbon content in ST52.4 makes it harder and stronger after undergoing heat treatment. However, this increase in hardness comes at the expense of reduced ductility and a lower melting point compared to ST37.4.

When choosing between these two grades, it's important to consider the specific requirements of the application. ST37.4 might be preferred for applications where ductility and weldability are critical, while ST52.4 could be chosen for applications where higher strength and hardness are needed, even if it means sacrificing some ductility.
​
Tensile strength ranges for ST52.4 from 490 N/mm² to 630 N/mm², while the ranges for ST37.4 are from 340 N/mm² to 480 N/mm². Different steel grades lead to different yield strengths too. The minimum yield strength for ST52.4 is 355 MPa and while for ST37.4 is 235 MPa. However, if the steel tubes with a thickness that is smaller than 3.0MM and an outside diameter that is smaller than 30MM and, the minimum yield strength is 10 MPa lower

3. How to make hydraulics steel tube? ​

Hydraulic Steel Tubes

​The finishing of tubes surface under ST37.4 and ST52.4 material are NBK, where the tubes are phosphate and normalized which provides corrosion resistance. It is oiled inside and outside. Normalize process creates tougher metal products. In the normalizing process, metals are heated to high temperatures and then allowed to naturally cool back down to room temperature by exposure after heating. Through the process, the metals are likely to be more formable, harder and ductile.

Galvanize coating is available upon request. Galvanise hydraulic tube comes with protective coating layer of zinc to make them longer lifetime. There are two types of galvanize, hot dipped galvanized and cold dipped galvanized.
​
The choice between hot-dipped and cold-dipped galvanizing for hydraulic steel tubes depends on factors such as the intended application, environmental conditions, and desired level of corrosion protection. Both methods play a crucial role in extending the lifespan and performance of hydraulic systems in various industrial and commercial settings.
Hot Dipped Galvanizing: 

1. Process - Involves immersing the steel tubes into a bath of molten zinc at a high temperature. The zinc reacts with the steel to form a metallurgical bond, creating a thick, durable coating.
2. Coating Thickness - Thicker and more robust compared to cold-dipped coatings. Provides a superior corrosion protection, making it ideal for harsh environments.
3. Application - Often preferred for large-scale production runs and applications where maximum corrosion resistance is required, such as outdoor structures, marine environments, and industrial equipment.

Cold Dipped Galvanizing: 

1. Process - Also known as electro-galvanizing, involves applying a thin layer of zinc onto the steel surface through an electrolytic process. Steel tubes are submerged in an electrolyte solution containing zinc ions, electric current is passed through the solution to deposit the zinc coating on the steel.
2. Coating Thickness - Thinner and more uniform compared to hot-dipped coatings. White not as corrosion-resistant as hot-dipped coatings, they still provide effective protection against rust and corrosion in less aggressive environments.
3. Applications - Often used for smaller-scale production runs, intricate parts, and applications where a thinner coating is sufficient, such as indoor structures, automotive components, and electrical enclosures.

There are two options of tube production, seamless or welded. Our hydraulics steel tubes are made from seamless process and it comes without a weld-join or a seam as it is drawn form a billet.

4. Hydraulics steel tube pressure ratings?
​
​Allowable working pressures are calculated using as per DIN 2413 at normal temperature. The yield and tensile stress values utilize to determine the maximum allowable running pressure and wall thickness required. The tubes and pipes are delivered the actual yield and tensile stress values are verified from the true copy material certificates. Pressure reduction factors at various temperatures show below:

° C	-40	120	150	175	​​​200	​250
° F	​-40	​248	​302	347	392	482
Rating Factor	0.90	1.0	​0.89	0.89	0.83	NA

​To determine allowance working pressure at elevated temperature, multiply allowable working pressure of the tube outer diameter and thickness at the rating factor after identify temperature reading. ​​

5. What are hydraulics steel tubes used for?​

Hydraulics steel tubes find wide-ranging applications across various industries due to their unique properties and suitability for demanding hydraulic systems. Some common applications include:

• Hydraulic Machinery

To facilitate the transmission of hydraulic fluid to generate and control mechanical motion in various industrial applications such as construction, agriculture and manufacturing.

• Aerospace and aviation

Utilized in aerospace applications where lightweights yet durable components are required to withstand extreme conditions.

• Oil and Gas Sector

Used in hydraulic fracturing operations, well drilling, and pipeline systems, providing reliable fluid transfer and control in harsh environments.

• Marine Industry

Applicable in marine applications for steering mechanism, anchor handling, and cargo handling equipment on ships and offshore platforms due to its ability to withstand the corrosive effects of seawater and harsh marine environments.

6. How do you build a hydraulic line? ​

Hydraulic tubes are suitable for welding according to usual techniques. A bending radius of 3x the external tube outer diameter is recommended for cold bending of tubes with instrument tube bender or manual hand bending. Welding Filler should be selected in accordance to DIN EN 1600 and DIN EN 12072 part 1 taking into account of the welding skill sets and type of application.

Here is the 4 simple steps process of hydraulics steel tube installation guidelines: 

DIN 2445/2 (ST37.4) Hydraulic Steel Tubes

Step 1: Cut the tube - You can either do this with a wheel cutter or mechanically cut the tube.

Step 2: Bend the tube - This is mostly done using hydraulic tube bender or manually bending.

Step 3: Welding - To weld, you go through three processes, the weld bevel process, choosing the appropriate welding methods and lastly carefully check your handiwork after welding.
​
Step 4: Installation - This is done when both the hydraulic component and connected equipment has been installed. After clarifying the sequence and become familiar with the pipe scheme, using a pipe clamp, you can reduce the tube vibration when flow went through. 

---

6. Hydraulics Steel Tube (ST37.4 NBK) Working Pressure Table:

 

No.	Description	Working Pressure (Bar)	Burst Pressure (Bar)	IMPA CODE
1	4MM OD x 1.0MM THK x 6 MTR	707	1755	710701
2	5MM OD x 1.0MM THK x 6 MTR	565	1404	-
3	6MM OD x 1.0MM THK x 6 MTR	471	1170	710702
4	6MM OD x 1.5MM THK x 6 MTR	707	1755	710703
5	8MM OD x 1.0MM THK x 6 MTR	353	878	710704
6	8MM OD x 1.5MM THK x 6 MTR	530	1316	710705
7	8MM OD x 2.0MM THK x 6 MTR	707	1755	710706
8	8MM OD x 2.5MM THK x 6 MTR	883	2194	-
9	10MM OD x 1.0MM THK x 6 MTR	283	702	710707
10	10MM OD x 1.2MM THK x 6 MTR	339	845	710708
11	10MM OD x 1.5MM THK x 6 MTR	424	1053	710709
12	10MM OD x 2.0MM THK x 6 MTR	565	1404	710710
13	10MM OD x 2.5MM THK x 6 MTR	707	1755	-
14	12MM OD x 1.0MM THK x 6 MTR	236	585	710711
15	12MM OD x 1.2MM THK x 6 MTR	283	702	710712
16	12MM OD x 1.5MM THK x 6 MTR	353	878	710713
17	12MM OD x 2.0MM THK x 6 MTR	471	1170	710714
18	12MM OD x 2.5MM THK x 6 MTR	589	1463	-
19	12MM OD x 3.0MM THK x 6 MTR	707	1755	-
20	14MM OD x 1.5MM THK x 6 MTR	303	752	-
21	14MM OD x 2.0MM THK x 6 MTR	404	1003	-
22	14MM OD x 2.5MM THK x 6 MTR	505	1254	-
23	14MM OD x 3.0MM THK x 6 MTR	606	1504	-
24	14MM OD x 4.0MM THK x 6 MTR	807	2006	-
25	15MM OD x 1.0MM THK x 6 MTR	188	468	-
26	15MM OD x 1.2MM THK x 6 MTR	226	562	710715
27	15MM OD x 1.5MM THK x 6 MTR	283	702	710716
28	15MM OD x 2.0MM THK x 6 MTR	377	936	710717
29	15MM OD x 2.5MM THK x 6 MTR	471	1170	710718
30	15MM OD x 3.0MM THK x 6 MTR	565	1404	-
31	16MM OD x 1.5MM THK x 6 MTR	265	658	710719
32	16MM OD x 2.0MM THK x 6 MTR	353	878	710720
33	16MM OD x 3.0MM THK x 6 MTR	530	1316	-
34	18MM OD x 1.5MM THK x 6 MTR	236	585	710721
35	18MM OD x 2.0MM THK x 6 MTR	314	780	710722
36	18MM OD x 2.5MM THK x 6 MTR	393	975	710723
37	18MM OD x 3.0MM THK x 6 MTR	471	1170	-
38	20MM OD x 2.0MM THK x 6 MTR	283	702	710724
39	20MM OD x 2.5MM THK x 6 MTR	353	878	710725
40	20MM OD x 3.0MM THK x 6 MTR	424	1053	710726
41	20MM OD x 3.5MM THK x 6 MTR	495	1229	-
42	20MM OD x 4.0MM THK x 6 MTR	565	1404	-

 

 

No.	Description	Working Pressure (Bar)	Burst Pressure (Bar)	IMPA CODE
43	20MM OD x 4.5MM THK x 6 MTR	636	1580	-
44	20MM OD x 5.0MM THK x 6 MTR	707	1755	-
45	22MM OD x 2.0MM THK x 6 MTR	257	638	710727
46	22MM OD x 2.5MM THK x 6 MTR	321	798	-
47	22MM OD x 3.0MM THK x 6 MTR	385	957	710728
48	22MM OD x 4.0MM THK x 6 MTR	514	1276	-
49	25MM OD x 2.0MM THK x 6 MTR	226	562	710729
50	25MM OD x 2.5MM THK x 6 MTR	283	702	710730
51	25MM OD x 3.0MM THK x 6 MTR	339	842	710731
52	25MM OD x 3.5MM THK x 6 MTR	396	983	-
53	25MM OD x 4.0MM THK x 6 MTR	452	1123	-
54	25MM OD x 5.0MM THK x 6 MTR	565	1404	-
55	28MM OD x 2.0MM THK x 6 MTR	202	501	-
56	28MM OD x 2.5MM THK x 6 MTR	252	627	710732
57	28MM OD x 3.0MM THK x 6 MTR	303	752	-
58	28MM OD x 4.0MM THK x 3 MTR	404	1003	-
59	28MM OD x 5.0MM THK x 6 MTR	505	1254	-
60	30MM OD x 2.0MM THK x 6 MTR	188	468	-
61	30MM OD x 2.5MM THK x 6 MTR	236	585	710733
62	30MM OD x 3.0MM THK x 6 MTR	283	702	-
63	30MM OD x 4.0MM THK x 6 MTR	377	936	-
64	30MM OD x 5.0MM THK x 6 MTR	471	1170	-
65	35MM OD x 2.0MM THK x 6 MTR	161	401	-
66	35MM OD x 2.5MM THK x 6 MTR	202	501	710734
67	35MM OD x 3.0MM THK x 6 MTR	242	602	-
68	35MM OD x 4.0MM THK x 6 MTR	323	802	710735
69	35MM OD x 5.0MM THK x 6 MTR	404	1003	-
70	38MM OD x 3.0MM THK x 6 MTR	223	554	-
71	38MM OD x 4.0MM THK x 6 MTR	297	739	-
72	38MM OD x 5.0MM THK x 6 MTR	372	924	-
73	42MM OD x 2.0MM THK x 6 MTR	135	334	-
74	42MM OD x 3.0MM THK x 6 MTR	202	501	-
75	42MM OD x 4.0MM THK x 6 MTR	269	669	710736
76	42MM OD x 5.0MM THK x 6 MTR	336	836	-
77	50MM OD x 3.0MM THK x 6 MTR	170	421	-
78	50MM OD x 5.0MM THK x 6 MTR	283	702	-
79	60MM OD x 3.0MM THK x 6 MTR	141	351	-
80	60MM OD x 5.0MM THK x 6 MTR	236	585	-
81	65MM OD x 6.0MM THK x 6 MTR	261	648	-
82	75MM OD x 3.0MM THK x 6 MTR	113	281	-
83	1/8"NB x 2.41MM THK x 6 MTR	649	1611	-
84	1/4"NB x 3.02MM THK x 6 MTR	618	1536	-

 

 

No.	Description	Working Pressure (Bar)	Burst Pressure (Bar)	IMPA CODE
85	3/8"NB x 3.2MM THK x 6 MTR	523	1298	-
86	1/2"NB x 3.0MM THK x 6 MTR	391	971	-
87	3/4"NB x 3.0MM THK x 6 MTR	312	774	-
88	1"NB x 3.5MM THK x 6 MTR	291	723	-
89	1"NB x 4.55MM THK x 6 MTR	378	939	-
90	1 1/4"NB x 4.85MM THK x 6 MTR	321	797	-
91	1 1/2"NB x 5.08MM THK x 6 MTR	295	734	-
92	2 1/2"NB x 6.3MM THK x 6 MTR	NIL	580	-
93	1/4"OD x 1.2MM THK x 6 MTR	534	1327	-
94	1/4"OD x 1.5MM THK x 6 MTR	668	1658	-
95	3/8"OD x 1.22MM THK x 6 MTR	362	899	-
96	3/8"OD x 1.5MM THK x 6 MTR	445	1105	-
97	1/2"OD x 1.5MM THK x 6 MTR	334	829	-
98	3/4"OD x 2.0MM THK x 6 MTR	297	737	-
99	3/4"OD x 2.64MM THK x 6 MTR	392	973	-
100	1"OD x 3.0MM THK x 6 MTR	334	829	-
101	1 1/4"OD x 3.0MM THK x 6 MTR	267	663	-
102	1 1/4"OD x 3.25MM THK x 6 MTR	289	719	-

 

7. Hydraulics Steel Tube (ST52.4 NBK) Working Pressure Table:

No.	Description	Working Pressure (Bar)	Burst Pressure (Bar)	IMPA CODE
103	10MM OD x 2.0MM THK x 6 MTR	799	1919	710710
104	12MM OD x 2.0MM THK x 6 MTR	666	1599	710714
105	14MM OD x 1.5MM THK x 6 MTR	428	1028	-
106	14MM OD x 2.0MM THK x 6 MTR	571	1371	-
107	15MM OD x 1.5MM THK x 6 MTR	400	959	710716
108	15MM OD x 2.0MM THK x 6 MTR	533	1279	710717
109	15MM OD x 2.5MM THK x 6 MTR	666	1599	710718
110	16MM OD x 1.5MM THK x 6 MTR	375	899	710719
111	16MM OD x 2.0MM THK x 6 MTR	500	1199	710720
112	16MM OD x 3.0MM THK x 6 MTR	749	1799	-
113	18MM OD x 1.5MM THK x 6 MTR	333	800	710721
114	18MM OD x 2.0MM THK x 6 MTR	444	1066	710722
115	20MM OD x 2.0MM THK x 6 MTR	400	959	710724
116	20MM OD x 2.5MM THK x 6 MTR	500	1199	710725
117	20MM OD x 3.0MM THK x 6 MTR	599	1439	710726
118	22MM OD x 2.0MM THK x 6 MTR	363	872	710727
119	25MM OD x 2.0MM THK x 6 MTR	320	768	710729
120	25MM OD x 2.5MM THK x 6 MTR	400	959	710730
121	25MM OD x 3.0MM THK x 6 MTR	480	1151	710731
122	25MM OD x 4.0MM THK x 6 MTR	639	1535	-
123	25MM OD x 5.0MM THK x 6 MTR	799	1919	-
124	28MM OD x 2.0MM THK x 6 MTR	285	685	-
125	28MM OD x 3.0MM THK x 6 MTR	428	1028	-
126	30MM OD x 2.0MM THK x 6 MTR	266	640	-
127	30MM OD x 3.0MM THK x 6 MTR	400	959	-
128	30MM OD x 4.0MM THK x 6 MTR	533	1279	-
129	35MM OD x 3.0MM THK x 6 MTR	343	822	-
130	35MM OD x 4.0MM THK x 6 MTR	457	1096	710735
131	38MM OD x 3.0MM THK x 6 MTR	315	757	-
132	38MM OD x 4.0MM THK x 6 MTR	421	1010	-
133	38MM OD x 5.0MM THK x 6 MTR	526	1262	-
134	42MM OD x 3.0MM THK x 6 MTR	285	685	-
135	42MM OD x 4.0MM THK x 6 MTR	381	914	710736
136	42MM OD x 5.0MM THK x 6 MTR	476	1142	-
137	45MM OD x 5.0MM THK x 6 MTR	444	1066	-
138	50MM OD x 5.0MM THK x 6 MTR	400	959	-
139	50MM OD x 6.0MM THK x 6 MTR	480	1151	-
140	50MM OD x 10.0MM THK x 6 MTR	799	1919	-
141	54MM OD x 6.0MM THK x 6 MTR	444	1066	-
142	60MM OD x 5.0MM THK x 6 MTR	333	800	-
143	60MM OD x 6.0MM THK x 6 MTR	400	959	-

 

No.	Description	Working Pressure (Bar)	Burst Pressure (Bar)	IMPA CODE
144	65MM OD x 8.0MM THK x 6 MTR	492	1181	-
145	66MM OD x 8.5MM THK x 6 MTR	515	1236	-
146	76.1MM OD x 6.3MM THK x 6 MTR	331	794	-
147	80MM OD x 10.0MM THK x 6 MTR	500	1199	-
148	90MM OD x 5.0MM THK x 6 MTR	222	533	-
149	90MM OD x 10.0MM THK x 6 MTR	444	1066	-
150	97MM OD x 12.0MM THK x 6 MTR	494	1187	-
151	100MM OD x 10.0MM THK x 6 MTR	400	959	-
152	115MM OD x 15.0MM THK x 6 MTR	521	1251	-
153	120MM OD x 12.0MM THK x 6 MTR	400	959	-
154	130MM OD x 15.0MM THK x 6 MTR	461	1107	-
155	150MM OD x 15.0MM THK x 6 MTR	400	959	-
156	190MM OD x 20.0MM THK x 6 MTR	421	1010	-
157	2"OD x 5.9MM THK x 6 MTR	464	1114	-
158	2"OD x 6.0MM THK x 6 MTR	472	1133	-

 

---

CATALOGUE :​

Hydraulics Steel Tubes

---

Ask a Question