Description

Send Inquiry

Xi'an Dongmeng Group Co., Ltd. is one of the most reliable manufacturers and suppliers of en 10305-1 e255 honed seamless steel tube in China, also supports customized service. With abundant experience, we warmly welcome you to wholesale cheap products in stock here and get free sample from our factory. For price consultation, contact us.

EN 10305-1 E255 Honed Seamless Steel Tube

Xi'an Dongmeng Group Co., Ltd. supplies E255 honed seamless steel tubes for hydraulic cylinder barrels, pneumatic cylinders and precision mechanical components. Each inquiry should define the steel delivery condition, finished bore, outside diameter, length and inspection requirements so that the quotation matches the intended manufacturing process.

E255, material number 1.0408, is a non-alloy quality steel. Its mechanical properties depend on the specified delivery condition, making the condition code an essential part of the purchasing specification.

EN 10305-1 E255 Honed Seamless Steel Tube Overview

An E255 honed tube combines a cold drawn seamless steel substrate with an internally finished bore. For cylinder manufacturers, the purchasing specification needs to address both the steel properties and the bore that will contact the piston seals.

A complete specification defines the delivery condition, finished bore limits, minimum remaining wall thickness, geometry, surface profile and inspection documents. These details help buyers compare quotations and reduce additional machining caused by incomplete requirements.

EN 10305-1 covers seamless cold drawn precision tubes. Its circular-tube scope specifies an outside diameter of 380 mm or less; this standard scope should be distinguished from the dimensions available for a particular order.

Technical Specification

Item	Purchasing specification
Steel grade	E255, material number 1.0408
Technical delivery standard	EN 10305-1:2016
Tube construction	Seamless, cold drawn
Delivery condition	Specify +C, +LC, +SR, +A or +N
Internal finish	Honed bore; identify the finishing process in the order
Ordered dimensions	OD × finished ID × length, or the dimension system shown on the drawing
Wall thickness	Define nominal wall and minimum permitted wall after finishing
Bore tolerance	Drawing limits or an agreed ISO tolerance class
Outside diameter tolerance	Specify the applicable limits for the selected delivery condition
Bore geometry	Roundness and cylindricity limits where required
Straightness	Agreed limit and measurement method
Surface texture	Specify Ra and any additional parameters required by the seal design
End preparation	Cutting tolerance, deburring, chamfers and machining according to the drawing
Inspection documents	Document type, traceability and supplementary reports agreed before production

Supply feasibility, quantity, packaging and delivery schedule are confirmed in the quotation.

E255 Chemical Composition

The following values are for cast analysis, expressed as mass percentages.

C, max.	Si, max.	Mn	P, max.	S, max.
0.21%	0.35%	0.40–1.10%	0.025%	0.025%

These E255 values are independently confirmed in tube manufacturers' technical data. trafiltubi.com

E255 appears among the additional grades in informative Annex A of EN 10305-1:2016. The E255 composition row does not specify a separate minimum aluminium content; aluminium requirements should therefore follow the applicable order specification rather than values copied from E235 or E355.

Mechanical Properties by Delivery Condition

The following E255 values apply at room temperature. Strength values are in MPa; elongation values are percentages.

Condition	Description	Tensile strength Rm	Yield strength ReH, min.	Elongation A, min.
+C	Cold drawn / hard; no final heat treatment	≥580	-	5%
+LC	Cold drawn / soft; limited drawing after heat treatment	≥520	-	8%
+SR	Cold drawn and stress relieved	≥520	375	12%
+A	Soft annealed	≥390	-	21%
+N	Normalized	440–570	255	21%

Condition descriptions follow EN 10305-1; the numerical E255 properties are also confirmed by manufacturer data. hublebas.co.uk

"-" indicates that the cited E255 table does not give a separate minimum yield value for that condition. If the design requires a particular yield strength, include it explicitly in the purchasing specification.

The 255 MPa minimum yield strength belongs to E255+N. E255+SR has a specified minimum yield strength of 375 MPa. Subsequent processing can change the material properties and should be considered when planning fabrication.

E235, E255 or E355?

Compare grades in the same delivery condition. The table below compares normalized tubes.

Grade	Material number	Rm in +N	ReH in +N, min.	A in +N, min.
E235	1.0308	340–480 MPa	235 MPa*	25%
E255	1.0408	440–570 MPa	255 MPa	21%
E355	1.0580	490–630 MPa	355 MPa*	22%

*For E235 and E355, the main standard table reduces these yield minima by 10 MPa when both OD ≤30 mm and wall thickness ≤3 mm. The E255 Annex A row has no corresponding reduction footnote. Propriedades mecânicas (10305-1)

Select the grade and condition together with the required finished wall thickness, fabrication route and service conditions. A grade change requires an engineering review of the complete component specification.

Dimensional Reference Examples

For a circular tube, nominal wall thickness is calculated as:

Wall thickness = (outside diameter − inside diameter) ÷ 2

Finished ID	Nominal OD	Calculated nominal wall
40 mm	50 mm	5 mm
80 mm	100 mm	10 mm
100 mm	120 mm	10 mm
140 mm	170 mm	15 mm
160 mm	190 mm	15 mm
200 mm	220 mm	10 mm
250 mm	290 mm	20 mm

These examples illustrate the dimensional relationship. Availability and manufacturing feasibility are confirmed for each inquiry.

For cylinder design, account for diameter tolerances, eccentricity, honing allowance and any local machining when defining the minimum finished wall thickness.

Finished Bore Tolerances

H8 and H9 are examples of ISO hole tolerance classes. For an H hole, the lower deviation is zero; the upper deviation depends on nominal diameter and tolerance grade.

Nominal bore diameter	H8 deviation	H9 deviation
>18 to 30 mm	0 / +0.033 mm	0 / +0.052 mm
>30 to 50 mm	0 / +0.039 mm	0 / +0.062 mm
>50 to 80 mm	0 / +0.046 mm	0 / +0.074 mm
>80 to 120 mm	0 / +0.054 mm	0 / +0.087 mm
>120 to 180 mm	0 / +0.063 mm	0 / +0.100 mm
>180 to 250 mm	0 / +0.072 mm	0 / +0.115 mm

The tolerance widths follow ISO 286-2. For example, a 100 mm H8 bore has diameter limits of 100.000–100.054 mm. ISO 286-2:2010

Specify the tolerance class required by the piston and seal design. Bore diameter tolerance should be accompanied by any necessary roundness, cylindricity and straightness limits.

Bore Surface Requirements

Honing uses abrasive tools with rotational and reciprocating motion to finish the internal bore. Skiving and roller burnishing uses cutting tools followed by rollers, so the two processes should be identified separately in purchasing documents. Sunnen – Sunnen Products Company

Specify the surface profile recommended for the selected seals. Where applicable, include:

Ra and Rz limits.

Material ratio Rmr and its measurement settings.

Measurement direction and inspection locations.

Requirements for scratches, burrs and residual machining contamination.

Seal manufacturers assess surface profile using parameters beyond Ra alone. Consequently, a universal Ra range should not replace the requirements of the selected sealing system.

Inspection and Quality Documentation

Agree on the inspection scope before placing the order.

Inspection item	Information to specify
Material identification	Grade, delivery condition and heat identification
Chemical composition	Cast analysis linked to the supplied material
Mechanical properties	Required tests and applicable condition
Dimensions	OD, finished ID, length and wall acceptance limits
Bore geometry	Roundness, cylindricity and straightness where required
Surface texture	Parameters, limits and measurement settings
Visual condition	Agreed acceptance criteria for surfaces and ends
Additional testing	NDT method, coverage and acceptance level when required
Inspection documents	EN 10204 document type and supplementary reports

Where an EN 10204 Type 3.1 inspection certificate is required, state this in the inquiry. Also specify the finished-bore measurements and inspection records needed for incoming acceptance.

Applications and Fabrication

E255 honed tubes may be specified for hydraulic and pneumatic cylinder barrels, industrial actuators and precision sleeves when the material condition, dimensions and bore finish meet the component design.

The allowable working pressure requires assessment of the complete cylinder, including minimum wall thickness, temperature, cyclic loading, ports, joints and end connections. The grade designation alone does not establish a cylinder pressure rating.

Plan welding, machining and heat treatment in relation to the required final bore. Before assembly, verify cleanliness, seal compatibility, end preparation and the completed component's acceptance requirements.

Request an E255 Honed Tube Quotation

Send your drawing or specification with:

E255 grade and required delivery condition.

Finished bore diameter and tolerance.

Outside diameter and minimum finished wall requirement.

Tube length and cutting tolerance.

Bore surface and geometry requirements.

End machining or chamfer details.

Quantity and delivery destination.

Inspection documents, testing and packaging requirements.

Example inquiry

EN 10305-1 E255+SR honed seamless tube; OD 120 mm × finished ID 100 mm H8 × length 2,000 mm. Please quote against the attached drawing, including its surface texture, minimum wall, inspection and packaging requirements.

CTA button: Request a Quote
Supporting text: Send your drawing for material, bore-finish and dimensional review.

Frequently Asked Questions

1. What is E255 steel?

E255 is a non-alloy quality steel with material number 1.0408. It is included among the additional grades in Annex A of EN 10305-1:2016. Specify both E255 and the required delivery condition when ordering.

2. Does E255 always have a minimum yield strength of 255 MPa?

The 255 MPa minimum applies to E255+N. E255+SR has a specified minimum of 375 MPa. The other listed conditions have different tensile strength and elongation requirements. trafiltubi.com

3. Should I choose E255+SR or E255+N?

Compare the required strength, elongation and subsequent fabrication. The listed +SR values are Rm ≥520 MPa, ReH ≥375 MPa and A ≥12%; +N gives Rm 440–570 MPa, ReH ≥255 MPa and A ≥21%. Final selection belongs in the approved component specification.

4. How does E255 compare with E235 and E355?

In the normalized condition, E255 has a higher listed minimum yield strength than E235 and a lower one than E355. Their chemistry, tensile ranges and elongation requirements also differ, so substitution needs a complete specification review.

5. Does EN 10305-1 automatically require a honed bore?

The standard addresses the delivery of seamless cold drawn precision tubes. Finished honing, final bore limits and seal-specific surface requirements should be stated separately in the order. nen.nl

6. What does a 100 mm H8 bore mean?

Its diameter limits are 100.000–100.054 mm. The H8 designation controls bore size; additional geometry requirements should be specified where needed.

7. Is Ra 0.2–0.8 μm mandatory for E255 honed tubes?

That range is not a universal finished-honing requirement of EN 10305-1. Define the surface profile for the selected seals, including additional parameters such as Rz and Rmr where required.

8. Can E255 tube be welded without preheating?

Determine the welding procedure using the actual material composition, delivery condition, wall thickness, joint design and service requirements. Welding behaviour depends on both the material and the preparation and execution of the weld. hublebas.co.uk

9. Is E255 directly interchangeable with a DIN or ASTM grade?

Approve any substitution after comparing chemistry, delivery condition, mechanical properties, tolerances and inspection requirements. ASTM A519 covers seamless mechanical tubing, but a shared application does not establish grade equivalence. store.astm.org

10. What information is needed for a quotation?

Provide the delivery condition, finished ID and tolerance, OD, length, minimum wall, surface requirements, quantity and destination. Attach the drawing and identify required inspection documents, testing and packaging.