Steel grades for hydraulic cylinders
| EN 10305-1 | E355 |
| EN 10 294-1 | 20MnV6 |
| STN/ČSN 42 0260 | 11 523 |
| DIN 2391-2 | St52 |
| DIN 17100 | St52-3 |
Tubes for hydraulic cylinders
Tubes for mechanical machining – type HPZ are precision seamless tubes for the production of hydraulic cylinders or seals of piston rods. The inner working surface is obtained by mechanical machining, by honing or peeling and subsequent rolling.
Tubes intended for piston rods and telescopic cylinders – type HPK are cold drawn seamless tubes for piston rods, telescopic cylinders and cylinder liners. Use of tube piston rods and pistons is often preferable than the use of solid materials. Use of the tube material, which exhibits the same resistance to load stress, bending and in torsion, means a significant reduction in the weight of the cylinder.
Dimensions of hydraulic cylinder tubes
Precision tubes for mechanical machining – HPZ type
| INNER DIAMETER (ID) | 40,0 – 110,0 mm |
| WALL THICKNESS (WT) | 4,0 – 10,0 mm |
| EUROPEAN STANDARDS | EN 10305-1, DIN 2391, STN/ČSN 42 6711, STN/ČSN 42 6712 |
Precision tubes destined for piston rods – type HPK
| OUTER DIAMETER (OD) | 40,0 – 120,0 mm |
| WALL THICKNESS (WT) | 5,0 – 10,0 mm |
| EUROPEAN STANDARDS | EN 10305-1, EN 10294-1, DIN 2391 |
Tolerances for hydraulic cylinders
for mechanical machining – HPZ type
Tolerances of the outside diameter (OD) HPZ tubes meet the appropriate dimensional table standards. Tolerances values of the inside diameter (ID) are presented in the table .
Tolerance of the wall thickness is -/+ 7.5% of the wall thickness.
HPZ tubes eccentricity is included in the wall thickness tolerance
Length of tubes for hydraulic cylinders
(a), manufactured length of precision tubes in the range of 3 to 6 meters
(b), maximum precise length 6 meters
Tube testing
Selection of the tests is either according to standards or upon agreement with customer:
• cast / chemical analysis,
• tensile test,
• dimensional inspecti,
• visual inspection,
• NDT to find longitudinal defects.
Other tests are possible upon agreement.
Tubes ends
Upon agreement the tubes may be capped with plastic caps.
Cylinder tubes surface protection
The surface of the tubes is oiled.
Packaging tubes for hydraulic cylinders
Tube are packed in round or hexagonal bundles with weight max. 2 000 kg, fastened with steel strips.
Marking of tubes
The tubes are marked along the length of the tube where the following pieces of information are used:
(a), manufacturers’ logo,
(b), dimension (OD x ID),
(c), steel,
(d), heat number,
(e), the number of standard,
(f), other data as per the customers’ request.
