Xi'an Dongmeng Group Co., Ltd. is one of the most reliable manufacturers and suppliers of ASTM A519 4140 Honed Tube for Hydraulic Cylinders 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.

 

ASTM A519/A519M is the standard specification for seamless carbon and alloy steel mechanical tubing.

The current ASTM A519/A519M-24a covers hot-finished and cold-finished seamless mechanical tubing. Round tubing is covered up to and including 12¾ inches, or 325 mm, outside diameter. The standard also covers square, rectangular and special sections when specified by the purchaser.

A 4140 honed tube combines three separate requirements:

ASTM A519 defines the seamless mechanical-tubing product.

SAE 4140 defines the chromium-molybdenum alloy-steel grade.

Honing or SRB defines the precision finishing process applied to the internal diameter.

Compliance with ASTM A519 alone does not automatically guarantee:

H8 or H9 inside-diameter tolerance

Ra 0.2 or 0.4 μm surface finish

A specific yield strength

A specific hardness

A hydraulic-cylinder working pressure

A quenched-and-tempered condition

These requirements must be stated separately in the purchase order.

Material: SAE 4140 / ASTM A519 Grade 4140

Product Type: Seamless Mechanical Tube / Hydraulic Cylinder Barrel

Manufacturing Route: Hot Pierced / Cold Drawn / Precision Finished

ID Processing: Honed / Skived and Roller Burnished

ID Tolerance: H8 / H9 / H10 or Drawing-Specific

Typical ID Roughness: Ra 0.2–0.4 μm, subject to process and specification

Heat-Treatment Options: Annealed / Normalized / Stress Relieved / Quenched and Tempered

Typical Supply Range: OD 40–260 mm / Wall 5–25 mm, subject to mill confirmation

Length: Up to 12 m, subject to outside diameter, wall and straightness requirements

Testing: Chemical Analysis / Hardness / Tensile / UT / Eddy Current / Dimensional Inspection

Documents: EN 10204 3.1 MTC / NDT Report / Inspection Report

Processing: Cutting / Honing / SRB / Turning / Boring / Threading / Port Machining

 

Requirement	ASTM A519/A519M
Product Type	Seamless mechanical tubing
Steel Types	Carbon and alloy steel grades
Manufacturing Condition	Hot finished or cold finished
Maximum Round-Tube OD	325 mm
Available Shapes	Round, square, rectangular and special
Heat Analysis	Required according to the specified grade
Optional Requirements	Must be stated in the purchase order
Primary Application	Mechanical and engineering components
Automatic Pressure Rating	Not provided

ASTM A519 describes the mechanical tubing product and manufacturing requirements. Hydraulic-cylinder design pressure must be calculated separately according to material condition, tube geometry, end construction, ports, cyclic loading and the applicable engineering design rules.

SAE 4140 is a medium-carbon chromium-molybdenum alloy steel designed for heat treatment.

Its main advantages include:

Good hardenability

High strength after quenching and tempering

Useful toughness

Good fatigue performance

Ability to receive induction hardening

Suitability for heavy mechanical components

Ovako describes 42CrMo4 and SAE 4140-related variants as steels for quenching and tempering with a useful combination of strength and toughness. The final through-hardening response depends on section size and heat-treatment conditions.

 

Element	Typical Range
Carbon, C	0.38–0.43%
Silicon, Si	0.15–0.35%
Manganese, Mn	0.75–1.00%
Phosphorus, P	0.035% maximum
Sulfur, S	0.040% maximum
Chromium, Cr	0.80–1.10%
Molybdenum, Mo	0.15–0.25%
Iron, Fe	Balance

These are commonly used SAE 4140 composition limits. Final material acceptance must be based on the ASTM A519 heat analysis and the heat-specific Mill Test Certificate.

SAE J404 is the SAE standard covering chemical compositions of SAE alloy steels. The purchase order should state both ASTM A519/A519M and Grade 4140 rather than using "4140 steel" alone.

Item	SAE 4140	EN 42CrMo4
Main Designation System	SAE / ASTM purchasing system	European EN system
Common Material Number	-	1.7225
Material Family	Chromium-molybdenum Q&T steel	Chromium-molybdenum Q&T steel
Typical Use	Mechanical tubing, shafts and heavy components	Tubes, bars, shafts and engineering parts
Automatic Equivalence	No	No
Purchase Requirement	ASTM A519 + Grade 4140	Relevant EN product standard + 42CrMo4

4140 and 42CrMo4 are commonly cross-referenced because they belong to the same chromium-molybdenum steel family. However, their permitted chemistry, heat treatment, testing and product-standard requirements are not automatically identical.

Ovako lists AISI 4140 and 42CrMo4 as similar designations while also providing variants with specific chemistry, cleanliness and heat-treatment requirements.

Do not substitute 42CrMo4 for ASTM A519 Grade 4140 without purchaser approval.

Parameter	Typical Supply Option
Material	ASTM A519 Grade 4140
Product	Seamless hydraulic cylinder tube
Manufacturing Route	Hot pierced and cold drawn
Typical Outside Diameter	40–260 mm
Typical Wall Thickness	5–25 mm
Maximum ASTM Scope	325 mm OD for round tube
Standard Length	5.8 / 6 / 11.8 / 12 m
Custom Length	Saw-cut fixed lengths
ID Condition	Honed or SRB
ID Tolerance	H8, H9, H10 or custom
Surface Roughness	Ra 0.2–0.4 μm typical
OD Condition	As-drawn, turned, ground or machined
Straightness	Agreed according to length and processing
Heat Treatment	Annealed, normalized, stress relieved or Q&T
End Condition	Plain, faced, beveled or machined
Protection	Internal oil and external rust protection
Documentation	MTC, NDT and dimensional inspection report

The exact manufacturing range depends on the relationship between outside diameter, inside diameter, wall thickness, length, heat-treatment condition and final tolerance.

Do not combine the existing page's conflicting 4–260 mm and 12.7–304.8 mm ranges. Every published size must be supported by the actual qualified mill route.

Item	Honed ID	Skived and Roller Burnished ID
Process	Controlled abrasive finishing	Cutting followed by roller burnishing
Material Removal	Gradual and relatively low	Faster controlled stock removal
Geometry Correction	Strong capability	Depends on incoming-tube geometry
Surface Texture	Fine cross-hatch pattern	Smooth roller-burnished texture
Typical Roughness	Ra approximately 0.2–0.4 μm	Can reach maximum Ra approximately 0.30 μm
Typical Use	Precision cylinders and repair barrels	High-volume hydraulic cylinder production
ID Tolerance	H8, H9 or specified tolerance	H8, H9 or specified tolerance
Main Buying Factor	Geometry and finish control	Productivity and smooth finished bore

Tenaris specifies that skived and roller-burnished hydraulic cylinder tubes can be supplied to ISO 286-2 ID tolerance classes, with a maximum worked-surface roughness of approximately Ra 0.30 μm when the option is specifically ordered.

The buyer should not order only "honed tube." The specification should state:

Finished internal diameter

ID tolerance class

Surface roughness Ra

Surface roughness Rz when required

Roundness

Cylindricity

Straightness

Required stock allowance

Honed or SRB process

Seal and piston application

H8 and H9 are ISO tolerance classes for holes under ISO 286-2.

They are not fixed tolerances such as "±0.02 mm" for every diameter. The permitted tolerance changes according to the nominal internal-diameter range.

For this reason, quotations should state:

Finished ID + ISO tolerance class

Example:

100 mm H8

or

100.000 / 100.054 mm, when the exact limits have been calculated and agreed.

Avoid publishing one universal H8 tolerance for every tube size.

ASTM A519 4140 tubing can be supplied in different manufacturing and heat-treatment conditions.

As Hot Finished

Suitable when substantial machining or additional heat treatment will be carried out by the buyer.

Cold Finished

Provides improved dimensional control and surface condition compared with hot-finished tubing.

Annealed

Reduces hardness and improves machinability. The actual annealing cycle and hardness must be agreed.

Normalized

Produces a refined structure and controlled mechanical condition before machining or additional heat treatment.

Stress Relieved

Reduces residual stresses generated by cold drawing and machining while retaining much of the existing strength.

Quenched and Tempered

Used when the finished cylinder barrel requires higher strength and hardness.

The final mechanical properties depend on:

Austenitizing temperature

Quenching medium

Tempering temperature

Tube wall thickness

Section size

Heating uniformity

Final machining allowance

A typical production route includes:

Alloy-steel billet and heat-number verification

Rotary piercing or hot extrusion

Hot rolling to hollow tube form

Pickling and surface preparation

Cold drawing to improve dimensions and wall control

Heat treatment according to the ordered condition

Straightening

Preliminary ID boring or skiving when required

Precision honing or roller burnishing

OD turning or grinding when specified

Fixed-length cutting

Dimensional and surface inspection

Nondestructive testing

Rust protection and export packaging

ASTM A519 defines seamless tubing as tubing manufactured without a welded seam, generally by hot working and, when required, subsequent cold finishing to achieve the specified dimensions and properties.

 

Inspection can be arranged according to the purchase order and cylinder drawing.

Material Inspection

Heat-number verification

Chemical analysis

Mill Test Certificate review

PMI when specified

Hardness testing

Tensile testing

Impact testing when required

Tube Inspection

Outside-diameter measurement

Finished inside-diameter measurement

Wall-thickness inspection

Wall-eccentricity inspection

Ovality and roundness

Straightness

Length

End squareness

Visual surface inspection

Finished-Bore Inspection

ID tolerance

Ra surface roughness

Rz surface roughness when specified

Honing pattern

Bore waviness

Taper

Cylindricity

Local scratches, chatter and spiral marks

Cleanliness and preservation

Nondestructive Testing

Ultrasonic testing

Eddy-current testing

Magnetic-particle testing for machined ends when required

Customer-specific NDT

EN 10204 3.1 Mill Test Certificate

Chemical composition report

Mechanical test report

Hardness report

Heat-treatment record

Ultrasonic test report

Eddy-current test report

ID dimensional report

Surface-roughness report

Straightness report

Certificate of Conformity

Third-party inspection report

Heat-number and packing list

 

ASTM A519 4140 honed tubes are used for:

Excavator hydraulic cylinders

Crane boom cylinders

Mobile-crane telescopic cylinders

Mining-equipment cylinders

Hydraulic presses

Injection-molding machinery

Forging and forming equipment

Industrial lifting systems

Agricultural machinery

Forklifts

Marine deck machinery

Offshore handling equipment

Heavy-duty rams

Accumulator shells

Mechanical sleeves

High-load actuator components

Seamless hydraulic-cylinder tubes are widely used in earth-moving machinery, cranes and energy-sector equipment where dimensional control, fatigue resistance and mechanical reliability are important.

Item	SAE 4140	SAE 4130
Carbon Level	Higher	Lower
Heat-Treated Strength Potential	Higher	Moderate
Hardenability	Higher	Lower
Welding Sensitivity	Higher	Generally easier to manage
Typical Selection	Heavy-load and higher-strength barrels	Welded structures and moderate-strength cylinders
Final Selection	Based on design calculations	Based on design calculations

4140 should not automatically replace 4130. The cylinder designer must review strength, toughness, weldability, wall thickness and heat-treatment requirements.

Item	SAE 4140	Carbon Steel Honed Tube
Alloying	Chromium-molybdenum alloy steel	Low- or medium-carbon steel
Heat-Treatment Capability	High	More limited
Strength Potential	Higher	Lower to moderate
Welding Procedure	More demanding	Generally simpler
Material Cost	Higher	Lower
Typical Application	Heavy-load and compact high-strength designs	General industrial hydraulic cylinders

The lowest material price does not necessarily provide the lowest completed-cylinder cost. Machining, welding, heat treatment, fatigue life and required wall thickness must also be considered.

Finished honed tubes require internal-surface protection during storage and shipment.

Packaging options include:

Rust-preventive oil inside and outside

Plastic end caps

Individual plastic sleeves

Waterproof wrapping

Foam or paper separators

Steel-strapped bundles

Reinforced wooden cases

Desiccant for sea shipment

Heat-number labels

Custom shipping marks

Tenaris specifies internal and external oiling as temporary rust protection for hydraulic-cylinder tubes stored in covered conditions.

The preservation period depends on packaging, humidity, storage conditions and transport duration.

Dongmeng Group provides seamless tube supply, precision processing, inspection and international delivery support.

The company profile reports five manufacturing centers, 18 production lines and 10 warehouses. Its manufacturing network includes a seamless steel pipe production center using piercing and extrusion processes, together with material inspection and export-logistics capabilities.

Customers can receive:

ASTM A519 4140 tube supply

Honed and SRB internal finishes

Custom ID tolerance

Multiple heat-treatment conditions

Fixed-length cutting

Drawing-based machining

MTC and NDT documentation

Third-party inspection

Internal rust protection

Export wooden-case packaging

FOB, CFR, CIF and DDP shipping support

For an accurate quotation, please provide:

Material grade

ASTM edition

Finished outside diameter

Finished inside diameter

Minimum wall thickness

Length

Quantity

Honed or SRB finish

ID tolerance class

Required Ra and Rz

Straightness requirement

Heat-treatment condition

Required hardness

Mechanical-property requirements

NDT requirements

End machining drawing

Cylinder working environment

Destination port or delivery address

Company: Dongmeng Group

Email: office@dongmjd.com

Phone / WhatsApp: +86 157 6921 4734

Website: www.cndmmetal.com

Is ASTM A519 a hydraulic pressure-pipe standard?

No. ASTM A519 is a seamless mechanical-tubing standard. The allowable cylinder pressure must be calculated from the finished component geometry, mechanical properties and applicable design rules.

Is 4140 honed tube always quenched and tempered?

No. It can be supplied hot finished, cold finished, annealed, normalized, stress relieved or quenched and tempered. The required condition must be stated in the order.

What is the difference between seamless and honed?

Seamless describes how the tube body is manufactured without a longitudinal weld. Honed describes the precision finishing process applied to the internal diameter.

What is the difference between honing and SRB?

Honing uses abrasive stones to refine bore geometry and surface texture. SRB combines skiving with roller burnishing and is commonly used for efficient production of smooth hydraulic-cylinder bores.

Can you supply an H8 internal diameter?

Yes. H8, H9 and other ISO tolerance classes can be quoted. The numerical tolerance depends on the nominal internal diameter under ISO 286-2.

Is Ra 0.4 μm suitable for hydraulic cylinders?

Ra 0.4 μm is commonly specified for honed hydraulic-cylinder bores, but the final requirement must match the piston seal, operating pressure, speed, lubrication and service-life target.

Does ASTM A519 specify Ra 0.4 μm?

No. ASTM A519 does not automatically specify the finished honed-bore roughness. Ra, Rz and ID tolerance must be added to the purchase order.

Are BK and NBK ASTM A519 conditions?

No. BK, GBK and NBK are associated with DIN/EN precision-tube delivery-condition terminology. ASTM orders should use clearly defined manufacturing and heat-treatment conditions.

Is SAE 4140 the same as 42CrMo4?

They are similar chromium-molybdenum steels but are not automatically interchangeable. The exact chemistry, product standard, heat treatment and testing must be checked.

Can 4140 tube be welded?

Yes, but welding requires a qualified procedure with appropriate preheat, consumables, heat-input control and post-weld evaluation.

What tests can be supplied?

Available tests include chemical analysis, tensile testing, hardness, UT, eddy current, dimensional inspection, surface-roughness measurement and third-party inspection.

Can you machine cylinder ports and ends?

Yes. Dongmeng Group can review fixed-length cutting, facing, boring, threading, grooves, ports and drawing-based end machining.

 

 

 

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