EN 10305-1 42CrMo4 and 34CrMo4 Hydraulic Cold-Drawn Seamless Steel Tube

EN 10305-1 cold-drawn seamless steel tubes are designed for precision applications requiring controlled dimensions, consistent wall thickness, low surface roughness, and reliable mechanical properties. The standard covers circular seamless cold-drawn tubes with outside diameters up to 380 mm.

This product combines precision cold-drawing technology with chromium-molybdenum alloy steels such as 42CrMo4 and 34CrMo4. These grades provide higher hardenability, fatigue resistance, and strength than conventional E215, E235, and E355 carbon steel tubes.

42CrMo4 is included among the alloy grades associated with EN 10305-1. For 34CrMo4 orders, the tube manufacturing, dimensions, surface quality, and inspection requirements can be specified according to EN 10305-1, while the steel chemistry and quenched-and-tempered properties are normally defined according to EN 10083-3 or another agreed material standard.

These tubes are suitable for the manufacture of heavy-duty hydraulic cylinder barrels where accurate dimensions, high cyclic-pressure resistance, machining stability, and dependable heat-treatment response are required.

Specifications

Main Features

High Strength after Quenching and Tempering

42CrMo4 tubes can achieve a minimum yield strength of approximately 900 MPa and a tensile strength of 1,100–1,300 MPa when quenched and tempered and when the relevant ruling section is not more than 16 mm.

34CrMo4 tubes can achieve a minimum yield strength of approximately 800 MPa and a tensile strength of 1,000–1,200 MPa under comparable quenched-and-tempered conditions.

The final guaranteed values depend on wall thickness, ruling section, heat-treatment parameters, specimen orientation, and the applicable material specification.

Controlled Chromium-Molybdenum Chemistry

42CrMo4 contains approximately 0.90–1.20% chromium and 0.15–0.30% molybdenum. This alloying combination improves hardenability and allows a higher-strength microstructure to be obtained through the tube wall.

34CrMo4 contains a similar chromium-molybdenum range but has a lower carbon content of approximately 0.30–0.37%. It therefore provides a useful balance between strength, toughness, machinability, and heat-treatment response.

Precision Cold-Drawn Dimensions

Cold drawing improves the repeatability of the outside diameter, inside diameter, wall thickness, roundness, and straightness compared with conventional hot-finished seamless tubes.

For selected dimensions, dimensional capability can be controlled within approximately ±0.05 mm. The final tolerance must be confirmed according to the tube size, wall thickness, delivery condition, and required machining allowance.

Multiple Heat-Treatment Conditions

The available EN 10305-1 delivery conditions include:

Suitable for Further Machining

The tubes can be supplied with machining allowance for boring, honing, skiving, roller burnishing, threading, drilling, or precision turning.

Stress-relieved or annealed delivery is recommended where substantial machining will be performed. Quenched-and-tempered delivery is suitable where the finished component requires higher strength and fatigue resistance.

Our Advantages

Dimensional Control for Cylinder-Barrel Machining

A common purchasing concern is whether the tube will retain sufficient machining allowance while avoiding excessive boring or honing time.

The outside diameter, inside diameter, wall thickness, ovality, and straightness can therefore be inspected against an approved dimensional drawing. For fixed-length production, cutting and end-face squareness can also be controlled before shipment.

Inspection records can include:

Outside-diameter measurements at multiple positions

Wall-thickness measurements around the circumference

Inside-diameter measurements when accessible

Straightness inspection over the full tube length

Length and end-squareness inspection

This reduces the risk of insufficient machining allowance, excessive material removal, or inconsistent finished bore dimensions.

Heat-Treatment Traceability for 34CrMo4 and 42CrMo4

Chromium-molybdenum tube properties depend strongly on austenitizing temperature, quenching efficiency, tempering temperature, wall thickness, and furnace uniformity.

Each production batch can therefore be controlled by heat number and heat-treatment lot. Chemical composition, tensile properties, hardness, and heat-treatment condition can be recorded in an EN 10204 inspection certificate.

Where required, additional controls can include:

Hardness testing on each heat-treatment batch

Tensile testing by heat and size

Microstructure examination

Decarburization-depth inspection

Impact testing at an agreed temperature

This provides better traceability than relying only on a nominal grade designation.

Surface and Nondestructive Inspection before Shipment

Surface defects, internal discontinuities, and scale can increase machining loss or reduce fatigue performance in cyclic hydraulic service.

The tubes are therefore visually inspected and can be subjected to optional eddy-current, ultrasonic, magnetic-particle, or hydraulic testing according to the agreed acceptance criteria.

For machined hydraulic cylinder tubes, the internal surface can also be inspected for roughness, scoring, laps, pits, and local dimensional variation. Protective oil and end caps can be applied after inspection to reduce corrosion and contamination during transportation.

Execution Standards

Application

Heavy-Duty Hydraulic Cylinder Barrel

The tube is used to manufacture the cylinder barrel of a hydraulic cylinder for construction equipment.

A typical production route is:

Cold-drawn seamless tube production

Stress relieving, annealing, or quenching and tempering

Tube straightening and dimensional inspection

Inside-diameter boring or skiving

Roller burnishing or honing

End machining and port preparation

Surface cleaning and corrosion protection

Final pressure and dimensional inspection

42CrMo4 or 34CrMo4 is selected when the cylinder barrel requires greater strength, fatigue resistance, or resistance to mechanical shock than a conventional E355 precision tube can provide.

The required wall thickness and heat-treatment condition must be calculated according to maximum working pressure, pressure cycling, internal diameter, end-connection design, corrosion allowance, temperature, and the applicable pressure-equipment design rules.

Chemical Composition

Mechanical Properties

The values below represent different delivery conditions and must not be interpreted as directly interchangeable.

E215, E235, and E355 values apply to the normalized condition, +N.

34CrMo4 and 42CrMo4 values apply to the quenched-and-tempered condition for a ruling section not exceeding 16 mm. Different values apply to larger sections.

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A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,

it is according to quantity.

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A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.

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