ST52 Seamless Honed Tube – Product Description
1. Overview
ST52 seamless honed tubes are precision steel tubes with smooth inner bores, specifically designed for manufacturing hydraulic cylinder barrels, the core structural components of hydraulic cylinders.
Material: ST52.3 / ST52.4 seamless steel
Finishing: Honing or Skiving & Roller Burnishing (SRB) for optimal bore quality, tolerance, and surface finish
Additional Services: CNC machining for customized cylinder parts based on client drawings – a one-stop solution for hydraulic cylinder tubes and components
2. Commodity Name
ST52.3 / ST52.4 Honed Seamless Tube for Hydraulic Cylinder
3. Size Range
| Inner Diameter (ID) | 30mm – 500mm |
| Outer Diameter (OD) | 40mm – 580mm |
| Length | Up to 12 meters or customized |
4. Available Steel Grades
SAE / AISI: 1020, 1026, 1045, 4130, 4140
DIN: ST52, ST52.3, ST52.4
EN: E355, C45E, 25CrMo4, 42CrMo4, CK45, S45C, E410, E470
GB: 20#, 45#, 16Mn, Q345B–E, 25Mn, 27SiMn
JIS: STKM 13A, STKM 13C
5. Manufacturing Methods
6. Delivery condition:
| BK | BKW | BKS | GBK | NBK | Q+T |
| +C | +LC | +SR | +A | +N |
| Cold rolled | Cold drawn | Stress relieved | Annealed | Normalized | Quenched+Tempered |
7. Bore Treatment Options
Honing: Ra ≤ 0.25 μm (smooth surface)
Skiving & Roller Burnishing (SRB): Ra ≤ 0.35 μm (high efficiency)
Both meet *H8 tolerance* requirements for hydraulic cylinder tubes
8. End Finish
Honed tubes: Plain ends, square cuts, burr-free
SRB tubes: Slightly beveled ends
Custom ends: Available upon request
9. H8 tolerance:
| ID range | Tolerance | ID range | Tolerance |
| 18< d≤30 | +0/+0.033 | 180< d≤250 | +0/+0.072 |
| 30< d≤50 | +0/+0.039 | 250< d≤300 | +0/+0.081 |
| 50< d≤80 | +0/+0.046 | 300< d≤315 | +0/+0.081 |
| 80< d≤120 | +0/+0.054 | 315< d≤400 | +0/+0.089 |
| 120< d≤180 | +0/+0.063 | 400< d≤500 | +0/+0.097 |
10. Packing
Bundled with steel strips
Plastic end caps
Internal & external oil coating
Outer PVC or knitted bags
Custom labels & export markings available
11. Honing vs. Skiving & Roller Burnishing
Honing: Best for smaller diameters, excellent roundness & smoothness
SRB: High-speed production, ideal for large batch manufacturing
Both methods ensure consistent precision
Applications
Hydraulic cylinder barrels (OEM & aftermarket)
Custom ST52 hydraulic cylinder parts
Precision machinery
Pneumatic actuators & lifting systems
Seamless tube delivery cylinders
FAQs
Q1: What is your minimum order quantity?
A: 2–3 tons/size for OD ≤ 250mm; 10 tons/size for OD > 250mm. For special grades (E410, E470), MOQ is 10 tons.
Q2: What is your typical delivery time?
A: 40–60 days depending on size & quantity. Small bore tubes with high precision may take up to 30 days for honing alone.
Q3: Do you offer custom cylinder parts from ST52 tubes?
A: Yes, with turning, boring, grooving & complete machining services.
Q4: What payment terms are available?
A: T/T, L/C, or D/P depending on customer credit.
Q5: How is quality ensured?
A: 90% of tubes sourced from certified mills, full-stage inspection (dimensional, surface, mechanical tests).
Company Profile
Founded in 2002, Chengxin is a leading manufacturer of cold drawn, cold rolled, and hydraulic cold drawn seamless steel tubes, serving hydraulic cylinder OEMs and machinery manufacturers worldwide.
Key Facts:
32,000㎡ factory area
12 workshops with complete machining capabilities
Hydraulic cold drawing benches, honing & SRB production lines
In-house die making, equipment maintenance, and final QC control
OEM services for seamless tubes & cylinder parts
