DIN 2391 ST52 honed tubes are precision seamless steel tubes widely used in heavy-duty hydraulic equipment, including construction machinery, industrial presses, forklifts, and mobile hydraulic systems. Made from high-strength ST52 carbon-manganese steel, these tubes are cold-drawn, honed, or skived & roller-burnished (SRB) to achieve ultra-smooth internal surfaces, tight dimensional tolerances, and excellent wear and fatigue resistance. With precise ISO H7/H8 tolerances, consistent surface roughness (Ra 0.2–0.4 µm), and compatibility with O-rings, U-cups, and piston seals, DIN 2391 ST52 honed tubes are ideal for hydraulic cylinders, actuators, and industrial lifting applications. Their durability, mechanical strength, and machinability make them a preferred choice for heavy-duty hydraulic systems worldwide.
What is DIN 2391 ST52 Honed Tube?
DIN 2391 ST52 honed tube is a high-precision seamless steel tube manufactured from ST52 structural steel according to DIN 2391 standard. These tubes are cold-drawn and then honed or SRB finished to create a smooth inner bore, ensuring minimal friction, optimal sealing, and long-lasting hydraulic performance. They are widely used in heavy machinery, industrial presses, hydraulic cylinders, and high-pressure fluid systems.
Chemical Composition of ST52 Steel
| Element | Typical Content (%) |
|---|---|
| Carbon (C) | 0.17 – 0.22 |
| Silicon (Si) | 0.10 – 0.40 |
| Manganese (Mn) | 1.40 – 1.80 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
The balanced chemical composition ensures high tensile strength, excellent toughness, and good machinability for precision honing.
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 540 – 580 MPa |
| Yield Strength (Rp0.2) | 355 – 390 MPa |
| Elongation (A%) | 12 – 14 % |
| Hardness (HB) | 160 – 190 |
| Impact Toughness | ≥ 27 J @ 20°C |
Insight: ST52 provides sufficient strength and fatigue resistance for heavy-duty hydraulic equipment while remaining cost-effective compared to higher-alloy steel grades.
Dimensions & Tolerances
| Parameter | Range / Specification |
|---|---|
| Inside Diameter (ID) | 20 mm – 400 mm (custom available) |
| Outside Diameter (OD) | 30 mm – 420 mm |
| Wall Thickness | 2 mm – 35 mm |
| Length | 3 – 9 m (cut-to-length options) |
| Tolerance Class | ISO H7 / H8 / H9 |
| Surface Roughness | Ra ≤ 0.2 – 0.4 µm |
| Straightness | ≤ 1 mm / 1000 mm |
Key Benefits of DIN 2391 ST52 Honed Tubes
High Dimensional Accuracy: ISO H7/H8 tolerance for optimal cylinder performance
Smooth Inner Surface: Low friction, excellent for piston seals and hydraulic efficiency
Good Fatigue Resistance: Suitable for repeated heavy-duty cycles
Cost-Effective Material: ST52 steel balances strength and economy
Wide Size Availability: Flexible diameters, wall thicknesses, and lengths for diverse machinery
Products Applications
DIN 2391 ST52 honed tubes are widely used in:
Heavy-duty hydraulic cylinders for construction and industrial machinery
Forklifts and lifting equipment requiring high pressure and fatigue resistance
Hydraulic presses and industrial automation systems
Pneumatic actuators and fluid power equipment
FAQ
Q1: What is a DIN 2391 ST52 honed tube?
A: It is a high-strength, cold-drawn seamless steel tube made from ST52 carbon-manganese steel, manufactured according to DIN 2391 standard. The inner bore is precision-honed or skived & roller-burnished (SRB) for ultra-smooth surfaces, tight tolerances, and long service life. It is widely used in heavy-duty hydraulic cylinders and industrial hydraulic systems.
Q2: What are the typical mechanical properties?
Tensile Strength (Rm): 540–580 MPa
Yield Strength (Rp0.2): 355–390 MPa
Elongation (A%): 12–14%
Hardness (HB): 160–190
Q3: What sizes and tolerances are available?
Inside Diameter (ID): 20–400 mm (custom sizes available)
Outside Diameter (OD): 30–420 mm
Wall Thickness: 2–35 mm
Length: 3–9 m (cut-to-length available)
Tolerance: ISO H7/H8/H9
Surface Roughness (Ra): ≤ 0.2–0.4 µm
Q4: What applications are suitable for ST52 honed tubes?
Heavy-duty hydraulic cylinders for construction machinery
Industrial hydraulic presses and actuators
Forklifts, lifts, and material handling equipment
High-pressure fluid systems requiring tight tolerances and fatigue resistance
Q5: Can ST52 honed tubes be chrome-plated?
A: Yes. Internal chrome plating is often applied to increase wear resistance, corrosion protection, and cylinder lifespan.
Q6: What is the difference between ST52 and E355 honed tubes?
A:
ST52: Cost-effective, good strength and fatigue resistance, suitable for standard heavy-duty applications.
E355: Higher tensile and yield strength, better fatigue resistance, and slightly smoother bore, preferred for high-pressure or ultra-heavy-duty hydraulic cylinders.
Q7: How is the quality of ST52 honed tubes ensured?
Dimensional inspection (ID, OD, wall thickness)
Bore surface roughness measurement
Straightness and visual inspection
Mechanical testing (tensile, yield, elongation)
Optional non-destructive testing (NDT)
Q8: Are custom sizes and tolerances available?
A: Yes. Manufacturers can provide custom diameters, wall thicknesses, lengths, and tolerances to meet specific hydraulic equipment requirements.
Q9: What is the typical delivery time?
A: Standard sizes are usually ready for shipment within 2–4 weeks, while custom sizes may require 4–6 weeks, depending on order quantity and specifications.
Q10: Why choose DIN 2391 ST52 honed tubes for hydraulic cylinders?
A: They combine strength, precision, and cost-efficiency, ensuring long-lasting cylinder performance, minimal friction, and reliable sealing, making them ideal for heavy-duty industrial applications.
Xi'an Dongmeng Group Co., Ltd.
Your Trusted Supplier of DIN 2391 ST52 Honed Tubes for Hydraulic Cylinders
Our address
Room 4107, Runfeng Building, Sanqiao New Street, Weiyang District, Xi'an City, Shaanxi Province
Phone Number
+86 15769214734
