Precision Cold-Drawn Tubes for Hydraulic and Mechanical Components

Description

Goldenman supplies Cold Drawn Seamless Steel Tubes for hydraulic cylinders, pneumatic cylinders, machinery, automotive components, oilfield equipment, shafts, sleeves, rollers, axles and precision-machined parts.

The product range is manufactured from hot-finished seamless mother tubes that undergo one or more cold-drawing passes through precision dies and mandrels.

Cold drawing improves:

• Outside-diameter accuracy
• Inside-diameter accuracy
• Wall-thickness control
• Roundness
• Concentricity
• Straightness
• Surface finish
• Mechanical-property consistency
• Machining efficiency
• Finished-part material utilization

The complete product range includes:

• EN 10305-1 Seamless Cold-Drawn Precision Tubes
• ASTM A519 Seamless Mechanical Tubing
• E215, E235 and E355 Precision Tubes
• SAE/AISI 1010, 1020, 1026, 1035 and 1045 Tubes
• SAE/AISI 4130, 4140 and 8620 Alloy Tubes
• Legacy DIN 2391 St 35 and St 52 configurations
• Cold-Drawn Hard Tubes
• Cold-Drawn Soft Tubes
• Stress-Relieved Tubes
• Annealed Tubes
• Normalized Tubes
• Ready-to-Hone Cylinder Tubes
• Honed Tubes
• Skived and Roller-Burnished Tubes
• Precision Cut-to-Length Tubes
• Machined Tube Blanks
• Phosphated and Oiled Tubes
• Zinc-Coated Hydraulic Tubes

Standard commercial production covers outside diameters from 4 to 260 mm and wall thicknesses from 0.5 to 25 mm.

ASTM A519 mechanical-tube configurations extend to 325 mm OD, with larger EN 10305-1 project dimensions supplied according to the required grade, wall thickness, tolerance and delivery condition.

Product Short Description

Goldenman Cold Drawn Seamless Steel Tubes provide tighter dimensional tolerances and smoother internal and external surfaces than conventional hot-finished seamless pipe.

EN 10305-1 tubes are supplied in E215, E235 and E355 grades with +C, +LC, +SR, +A or +N delivery conditions.

ASTM A519 Mechanical Tubes are supplied in carbon and alloy grades including 1010, 1020, 1026, 1035, 1045, 4130, 4140 and 8620.

The finished tubes can be ordered by outside diameter and wall thickness, outside diameter and inside diameter, or inside diameter and wall thickness. Additional processing includes precision cutting, honing, skiving, roller burnishing, machining, bending, drilling, swaging and surface coating.

Product Highlights

• Seamless construction without a longitudinal weld
• Cold-drawn precision dimensional control
• EN 10305-1 precision-tube configurations
• ASTM A519 carbon- and alloy-steel mechanical tubes
• E215, E235 and E355 steel grades
• 1010, 1020, 1026, 1035 and 1045 carbon-steel grades
• 4130, 4140 and 8620 alloy-steel grades
• Standard OD range from 4 to 260 mm
• ASTM A519 sizes up to 325 mm OD
• Wall thicknesses from 0.5 to 25 mm
• Project-specific heavy-wall dimensions
• Round, square, rectangular and special sections
• OD × wall, OD × ID and ID × wall ordering
• Tight outside- and inside-diameter tolerances
• Controlled wall eccentricity
• Improved roundness and straightness
• Smooth internal and external surfaces
• +C Cold Drawn Hard condition
• +LC Cold Drawn Soft condition
• +SR Stress-Relieved condition
• +A Annealed condition
• +N Normalized condition
• Random and fixed-length supply
• Ready-to-hone machining allowance
• Honed and skived roller-burnished bores
• Phosphated, oiled and zinc-coated surfaces
• Eddy-current and ultrasonic inspection
• Dimensional and surface-roughness inspection
• EN 10204 3.1 and 3.2 documentation
• Cut-to-length and component-machining services

General Technical Specifications

Parameter	Available Range
Product	Cold Drawn Seamless Precision Steel Tube
Main standards	EN 10305-1 and ASTM A519/A519M
Legacy references	DIN 2391, St 35 and St 52
Manufacturing process	Seamless hot finished plus cold drawing
Standard outside diameter	4–260 mm
Extended ASTM A519 diameter	Up to 325 mm
Extended EN project diameter	Up to 380 mm
Standard wall thickness	0.5–25 mm
Heavy-wall configurations	Project-specific
Standard lengths	4–7 m random lengths
Fixed lengths	Precision cut and project-specific
Standard EN grades	E215, E235 and E355
ASTM carbon grades	1010, 1020, 1026, 1035 and 1045
ASTM alloy grades	4130, 4140 and 8620
Delivery conditions	+C, +LC, +SR, +A and +N
Ordering dimensions	OD × wall, OD × ID or ID × wall
Tube shapes	Round, square, rectangular and special sections
End condition	Square cut, deburred, beveled or machined
Surface condition	Black, bright, oiled, phosphated or zinc coated
Bore condition	Cold drawn, ready to hone, honed or roller burnished
Inspection	Dimensional, visual, mechanical and NDE
Documentation	EN 10204 2.2, 3.1 or 3.2

Product Standard Comparison

Standard	Product Category	Main Grades	Main Applications
EN 10305-1	Seamless cold-drawn precision tubes	E215, E235 and E355	Machinery, vehicles and precision components
ASTM A519	Seamless mechanical tubing	1010–4140 and other grades	Shafts, sleeves, cylinders and mechanical parts
EN 10305-4	Seamless cold-drawn hydraulic tubes	E235 and E355	Hydraulic and pneumatic pressure lines
DIN 2391	Legacy precision-tube reference	St 35 and St 52	Legacy European machinery and hydraulic specifications
EN 10297-1	Seamless mechanical and engineering tubes	E355 and alloy grades	General engineering and machined components

EN 10305-1 Seamless Precision Tubes

EN 10305-1 applies to seamless cold-drawn steel tubes used in precision applications.

The product is characterized by:

• Precisely controlled dimensions
• Defined outside-diameter tolerances
• Defined inside-diameter tolerances
• Controlled wall thickness
• Specified surface condition
• Controlled straightness
• Defined delivery condition
• Verified mechanical properties
• Inspection-document options

Typical applications include:

• Automotive components
• General engineering
• Machine construction
• Hydraulic-cylinder components
• Pneumatic-cylinder components
• Axles
• Shafts
• Rollers
• Sleeves
• Bushings
• Injection components
• Bearing rings
• Structural machine parts

EN 10305-1 Grade Range

E215 Precision Tube

E215 provides lower strength and high formability.

It is used for:

• Light mechanical components
• Furniture components
• Tube bending
• Tube forming
• Light-duty automotive parts
• Components requiring significant cold deformation

E235 Precision Tube

E235 provides a balance of:

• Strength
• Ductility
• Weldability
• Formability
• Machinability
• Dimensional stability

E235 is used for:

• Hydraulic components
• Pneumatic equipment
• Machine frames
• Cylinder parts
• Automotive components
• General mechanical fabrication
• Precision-welded assemblies

E355 Precision Tube

E355 provides increased yield and tensile strength.

It is used for:

• Hydraulic cylinders
• Heavy mechanical components
• Lifting equipment
• Construction machinery
• Agricultural machinery
• Oilfield-equipment components
• High-load shafts and sleeves
• Structural machine parts
• Components requiring reduced wall thickness at a given load

EN 10305-1 Chemical Composition

Grade	Carbon Max.	Silicon Max.	Manganese Max.	Phosphorus Max.	Sulfur Max.
E215	0.10%	0.05%	0.70%	0.025%	0.025%
E235	0.17%	0.35%	1.20%	0.025%	0.025%
E355	0.22%	0.55%	1.60%	0.025%	0.025%

Microalloying elements such as niobium, titanium and vanadium are controlled and reported when used.

E235 Mechanical Properties

Delivery Condition	Tensile Strength	Minimum Yield Strength	Minimum Elongation
E235 +C	480 MPa minimum	0.8 × tensile strength	6%
E235 +LC	420 MPa minimum	0.7 × tensile strength	10%
E235 +SR	420 MPa minimum	350 MPa	16%
E235 +A	315 MPa minimum	0.5 × tensile strength	25%
E235 +N	340–480 MPa	235 MPa	25%

E355 Mechanical Properties

Delivery Condition	Tensile Strength	Minimum Yield Strength	Minimum Elongation
E355 +C	640 MPa minimum	0.8 × tensile strength	4%
E355 +LC	580 MPa minimum	0.7 × tensile strength	7%
E355 +SR	580 MPa minimum	450 MPa	10%
E355 +A	450 MPa minimum	0.5 × tensile strength	22%
E355 +N	490–630 MPa	355 MPa	22%

For small-diameter, thin-wall tubes, the minimum yield value follows the applicable dimensional adjustment in the ordered standard.

Delivery Conditions

+C Cold Drawn Hard

The tube receives no heat treatment after the final cold-drawing pass.

+C provides:

• Highest cold-worked strength
• High dimensional stability
• Tight dimensional tolerances
• Reduced ductility
• Limited additional forming capacity
• Good machining performance

+C is used for:

• Machined sleeves
• Bearing components
• Rollers
• Structural machine parts
• Components that do not require substantial bending or forming

+LC Cold Drawn Soft

The tube receives a controlled light cold-drawing pass after the final heat treatment.

+LC provides:

• Controlled dimensional accuracy
• Greater ductility than +C
• Limited cold-forming capability
• Smooth surfaces
• Stable mechanical properties

+LC is used for:

• Light bending
• Flaring
• Expanding
• Swaging
• Formed machine components

+SR Stress Relieved

The tube undergoes controlled stress-relief heat treatment after the final cold-drawing pass.

+SR provides:

• Reduced residual stress
• Improved dimensional stability during machining
• Reduced distortion after cutting
• High mechanical strength
• Improved component consistency
• Better performance during honing and boring

+SR is used for:

• Hydraulic-cylinder barrels
• Precision-machined sleeves
• Long machined parts
• Heavy-duty machinery
• Components with tight final geometry

+A Annealed

The tube is annealed after final cold drawing.

+A provides:

• High ductility
• Reduced hardness
• Improved formability
• Improved expansion capability
• Improved deep-forming performance

+A is used for:

• Significant bending
• End forming
• Flaring
• Expanding
• Complex fabricated components

+N Normalized

The tube is normalized in a controlled atmosphere after final cold drawing.

+N provides:

• Uniform fine-grain structure
• Balanced strength and ductility
• Stable mechanical properties
• Good weldability
• Good cold-forming performance
• Reduced residual stress

+N is used for:

• Welded mechanical assemblies
• Hydraulic equipment
• Automotive components
• Structural machinery
• Components requiring both forming and load capacity

Legacy ST37, ST35 and ST52 References

ST37 and ST52 remain common commercial search and purchasing terms.

For modern precision-tube orders, the final specification should use the current EN grade and delivery condition.

Common commercial references include:

Legacy Reference	Modern Purchasing Grade
St 35 / ST37 strength class	EN 10305-1 E235
St 52	EN 10305-1 E355

The exact replacement is determined from:

• Original DIN standard
• Chemical composition
• Delivery condition
• Mechanical properties
• Tube dimensions
• Intended application

A complete modern order should state:

• EN 10305-1
• E235 or E355
• +C, +LC, +SR, +A or +N
• OD and wall thickness
• Required tolerances
• Inspection certificate

ASTM A519 Seamless Mechanical Tubing

ASTM A519 covers seamless carbon- and alloy-steel mechanical tubing in hot-finished and cold-finished conditions.

Cold-finished ASTM A519 tubing is used where the purchaser requires:

• Controlled OD
• Controlled ID
• Controlled wall thickness
• Improved surface finish
• Straightness
• Concentricity
• Machining allowance
• Specific carbon- or alloy-steel grade

Available shapes include:

• Round
• Square
• Rectangular
• Oval
• Special sections

ASTM A519 Carbon-Steel Grades

SAE/AISI 1010

1010 is a low-carbon steel with high formability.

Applications include:

• Light-duty sleeves
• Bushings
• Formed components
• Welded assemblies
• Low-load machine parts

SAE/AISI 1020

1020 provides:

• Good machinability
• Good weldability
• Moderate strength
• Good cold-forming performance

Applications include:

• Shafts
• Pins
• Bushings
• Light-duty hydraulic components
• General machine parts

SAE/AISI 1026

1026 is a principal Cold Drawn Seamless mechanical-tube grade.

It provides:

• Increased strength over 1020
• Good machinability
• Good weldability
• Strong dimensional stability
• Broad size availability
• Reliable cold-drawing response

Applications include:

• Hydraulic-cylinder barrels
• Mechanical sleeves
• Rollers
• Axles
• Heavy equipment
• Automotive components
• Machined tubular parts

SAE/AISI 1035

1035 provides increased carbon content and strength for:

• Shafts
• Pins
• Mechanical rollers
• High-load sleeves
• Heat-treated machine components

SAE/AISI 1045

1045 provides:

• Higher strength
• Good wear resistance
• Heat-treatment capability
• Good machining performance

Applications include:

• Heavy-duty shafts
• Hydraulic piston components
• Rollers
• Axles
• Drill-equipment parts
• High-load mechanical sleeves

ASTM A519 Alloy-Steel Grades

SAE/AISI 4130

4130 chromium-molybdenum steel provides:

• High strength-to-weight ratio
• Good toughness
• Good weldability
• Heat-treatment capability
• Fatigue resistance

Applications include:

• Oilfield equipment
• Hydraulic components
• Aircraft and motorsport components
• High-pressure mechanical systems
• Structural tubular parts

SAE/AISI 4140

4140 chromium-molybdenum steel provides:

• High tensile strength
• Wear resistance
• Fatigue resistance
• Heat-treatment response
• High-load capability

Applications include:

• Heavy-duty cylinders
• Drive shafts
• Tool bodies
• High-load sleeves
• Oilfield machinery
• Mining equipment
• Mechanical power-transmission components

Available conditions include:

• Annealed
• Normalized
• Quenched and tempered
• Stress relieved
• Cold finished

SAE/AISI 8620

8620 nickel-chromium-molybdenum steel provides:

• Case-hardening capability
• Tough core properties
• Wear-resistant finished surfaces
• Good fatigue resistance

Applications include:

• Bearing sleeves
• Gears
• Bushings
• Power-transmission components
• Case-hardened tubular parts

EN 10305-1 vs ASTM A519

Selection Factor	EN 10305-1	ASTM A519
Main market	Europe and international precision engineering	North America and international machinery
Product focus	Precision cold-drawn tubes	Mechanical tubing
Main carbon grades	E215, E235 and E355	1010, 1020, 1026, 1035 and 1045
Alloy grades	Project-specific	4130, 4140, 8620 and others
Delivery condition	+C, +LC, +SR, +A and +N	Hot finished, cold finished or specified heat treatment
Dimensional ordering	OD × wall, OD × ID or ID × wall	OD and wall or purchaser-specified dimensions
Typical use	Automotive, machinery and precision components	Machined mechanical and alloy components
Inspection documents	EN 10204 format	ASTM material-test reporting

Cold Drawing Process

Cold drawing begins with a seamless hot-finished mother tube.

The tube is pulled through a precision die while an internal mandrel or plug controls the bore.

The process reduces:

• Outside diameter
• Inside diameter
• Wall thickness
• Dimensional variation
• Surface roughness
• Ovality

One or more drawing passes are used to obtain the required final dimensions.

Intermediate heat treatment restores ductility between drawing passes when required.

Cold Drawing with a Mandrel

Mandrel drawing controls both external and internal dimensions.

It provides:

• Tight ID tolerance
• Improved bore finish
• Controlled wall thickness
• Improved concentricity
• Reduced machining allowance
• Consistent hydraulic-cylinder bore stock

Mandrel-drawn tubes are used for:

• Cylinder barrels
• Pump barrels
• Precision sleeves
• Bearing housings
• Components machined from both the OD and ID

Sinking Without an Internal Tool

Tube sinking reduces the outside diameter without using a fixed internal mandrel.

It provides:

• Economical OD control
• Reduced outside diameter
• Increased wall thickness relative to diameter
• Suitable dimensions for parts primarily machined on the OD

Sunk tubes provide less direct ID control than mandrel-drawn tubes.

Dimensional Ordering Methods

Outside Diameter × Wall Thickness

Example:

60 × 5 mm

This method is used when:

• External fit controls the component
• The bore can vary within wall tolerance
• The tube will receive internal machining
• Standard tube dimensions are acceptable

Outside Diameter × Inside Diameter

Example:

60 × 50 mm

This method is used when:

• Both external and internal fit matter
• Concentricity must be controlled
• Machining allowance must be minimized
• The tube serves as a cylinder or sleeve blank

Inside Diameter × Wall Thickness

Example:

50 mm ID × 5 mm wall

This method is used when:

• The internal bore is the critical functional dimension
• The tube is used for a cylinder barrel
• A piston, shaft or sliding component passes through the bore

Dimensional Tolerances

EN 10305-1 tubes are selected for tighter dimensional control than general hot-finished pipe.

Standard inspection includes:

• Outside diameter
• Inside diameter
• Wall thickness
• Ovality
• Eccentricity
• Straightness
• Length
• End squareness
• Surface roughness

Typical wall-thickness tolerance is controlled to the ordered standard, with project specifications available for tighter tolerances.

Special precision options include:

• Tight OD tolerance
• Tight ID tolerance
• Restricted wall eccentricity
• Restricted ovality
• Enhanced straightness
• Precision fixed lengths
• Controlled machining allowance
• Matched component batches

Straightness

Straightness directly affects:

• Machining setup
• Honing accuracy
• Cylinder alignment
• Shaft rotation
• Roller performance
• Finished-component runout

Goldenman supplies:

• Standard commercial straightness
• Precision straightness
• Machining-grade straightness
• Cylinder-barrel straightness
• Project-specific total-indicator-runout limits

Straightness is measured over the complete tube length and over defined local gauge lengths.

Surface Quality

Cold drawing produces smoother internal and external surfaces than hot-finished manufacture.

Available surface conditions include:

• Cold-drawn black
• Bright cold drawn
• Annealed bright
• Phosphated
• Oiled
• Pickled and oiled
• Zinc plated
• Zinc plated and passivated
• Shot blasted
• Machined
• Ground
• Polished

Surface inspection controls:

• Cracks
• Seams
• Laps
• Scales
• Pits
• Scratches
• Drawing marks
• Handling damage
• Decarburization
• Coating defects

Ready-to-Hone Tubes

Ready-to-Hone Tubes are cold drawn with controlled internal machining allowance.

They are supplied for subsequent honing by the cylinder manufacturer.

The bore includes allowance for:

• Removal of drawing marks
• Correction of minor ovality
• Achievement of final ID
• Achievement of final roughness
• Creation of the cross-hatch surface

Ready-to-Hone Tubes reduce raw-material removal compared with hot-finished mechanical tubing.

Honed Cylinder Tubes

Honing uses abrasive stones to produce the final internal bore.

Honed tubes provide:

• Accurate internal diameter
• Controlled cylindricity
• Controlled straightness
• Fine cross-hatch surface
• Improved seal lubrication
• Reduced seal wear
• Stable piston movement

Honed tubes are used for:

• Hydraulic cylinders
• Pneumatic cylinders
• Telescopic cylinders
• Lifting cylinders
• Steering cylinders
• Agricultural cylinders
• Mining cylinders
• Oilfield hydraulic equipment

Skived and Roller-Burnished Tubes

Skiving removes a controlled layer of material from the internal bore.

Roller burnishing then plastically compresses surface peaks to produce a smooth, hardened finish.

The process provides:

• High production efficiency
• Smooth internal surface
• Improved bore accuracy
• Increased surface hardness
• Reduced friction
• Improved seal life
• Consistent cylinder performance

Hydraulic-Line Tubes

Precision tubes for hydraulic and pneumatic pressure lines are supplied under EN 10305-4 configurations.

Available features include:

• E235 and E355 grades
• Normalized condition
• Smooth internal surfaces
• Controlled cleanliness
• Phosphated and oiled surface
• Zinc-coated external surface
• Cr6-free passivation
• High-pressure fluid compatibility
• Bending and flaring capability

Hydraulic-line orders include:

• Tube OD
• Wall thickness
• Working pressure
• Bend radius
• End-connection system
• Cleanliness requirement
• Surface coating

Mechanical Applications

Goldenman Cold Drawn Seamless Tubes are used in:

• Hydraulic cylinders
• Pneumatic cylinders
• Machine tools
• Oilfield equipment
• Drilling machinery
• Mud-pump components
• Mining machinery
• Construction equipment
• Agricultural equipment
• Automotive components
• Railway equipment
• Material-handling machinery
• Lifting equipment
• Textile machinery
• Injection systems
• Furniture components
• Industrial rollers
• Shafts and axles
• Bushings and sleeves
• Bearing rings
• Pump barrels
• Structural machine assemblies

Hydraulic Cylinder Applications

Cold-drawn precision tube is used for:

• Cylinder barrels
• Telescopic stages
• Piston sleeves
• Guide sleeves
• Accumulator bodies
• Hydraulic actuator housings

The tube is selected from:

• Finished bore
• Operating pressure
• Cylinder stroke
• Buckling load
• Wall thickness
• Material strength
• Bore finish
• Straightness
• Welding requirements
• Fatigue life

Machined Component Applications

Cold-drawn tubes reduce machining time for hollow components.

Typical parts include:

• Bushings
• Spacers
• Rollers
• Pins
• Bearing housings
• Gear blanks
• Hollow shafts
• Tool bodies
• Valve sleeves
• Piston bodies
• Drill-equipment components

Near-net-shape tube dimensions reduce:

• Material waste
• Boring time
• Turning time
• Tool consumption
• Component weight
• Total machining cost

Oilfield Equipment Applications

Cold Drawn Seamless Mechanical Tubes are used in:

• Hydraulic power units
• BOP control systems
• Power-tong cylinders
• Mud-pump components
• Winch cylinders
• Handling-tool components
• Hydraulic jacks
• Pressure-control equipment
• Mechanical sleeves
• Tool bodies
• Actuator components

Alloy grades such as 4130 and 4140 are used where higher load, toughness, wear resistance or heat-treatment response is required.

Material Selection Guide

Application	Common Grade and Condition
General precision component	E235 +N
Higher-load mechanical component	E355 +N
Machined high-strength sleeve	E355 +SR
Cold-formed component	E235 +A or +N
Hydraulic-cylinder barrel	E355 +SR or ASTM A519 1026
General mechanical tubing	ASTM A519 1020 or 1026
Heat-treated shaft or roller	ASTM A519 1045
Welded high-strength component	ASTM A519 4130
Heavy-duty wear component	ASTM A519 4140
Case-hardened component	ASTM A519 8620
Hydraulic pressure line	EN 10305-4 E235 or E355 +N

Grade and Condition Selection

The tube grade cannot be selected independently of its delivery condition.

For example:

• E355 +C provides very high cold-worked strength but limited ductility.
• E355 +SR retains high strength while reducing machining distortion.
• E355 +N provides lower strength than +C but substantially greater elongation.
• E235 +A provides increased formability for bending and end forming.

The procurement specification must state both the material grade and delivery condition.

Machining Services

Goldenman supplies finished and semi-finished tube components with:

• Precision sawing
• Facing
• Chamfering
• Deburring
• Turning
• Boring
• Honing
• Skiving
• Roller burnishing
• Grinding
• Polishing
• Drilling
• Milling
• Threading
• Grooving
• Taper machining
• Swaging
• End forming
• Heat treatment

Precision Cutting

Cut-to-length services include:

• Saw cutting
• Abrasive cutting
• Automatic high-volume cutting
• Short component blanks
• Long fixed lengths
• Tight length tolerance
• Controlled squareness
• Internal and external deburring

Cut pieces are packaged to protect machined ends and precision surfaces.

Bending and Forming

Available processing includes:

• Rotary-draw bending
• Mandrel bending
• Roll bending
• Flaring
• Expanding
• Reducing
• Swaging
• Beading
• End forming

The selected grade and delivery condition must provide sufficient elongation for the required deformation.

Welding

E235 +N and E355 +N are commonly selected for welded mechanical assemblies.

Welding preparation includes:

• End beveling
• Surface cleaning
• Fit-up control
• Weld-procedure qualification
• Preheat selection
• Interpass-temperature control
• Post-weld treatment where required

Higher-carbon and alloy grades require grade-specific welding procedures.

Manufacturing Process

Goldenman Cold Drawn Seamless Tube manufacturing includes:

1. Raw steel-billet verification
2. Heat-number assignment
3. Billet heating
4. Rotary piercing
5. Hot rolling or elongation
6. Mother-tube sizing
7. Mother-tube inspection
8. Pickling and descaling
9. Phosphating and lubrication
10. Tube pointing
11. Die and mandrel preparation
12. First cold-drawing pass
13. Intermediate heat treatment
14. Additional cold-drawing passes
15. Final heat treatment
16. Straightening
17. End cutting
18. Dimensional inspection
19. Surface inspection
20. Mechanical-property testing
21. Nondestructive examination
22. Surface protection
23. Permanent or bundle marking
24. Precision cutting or machining
25. Final inspection
26. Export packaging

Heat Treatment

Available heat-treatment processes include:

• Stress relieving
• Annealing
• Normalizing
• Normalizing and tempering
• Quenching and tempering
• Grade-specific controlled-atmosphere treatment

Heat treatment controls:

• Yield strength
• Tensile strength
• Elongation
• Hardness
• Toughness
• Residual stress
• Machinability
• Dimensional stability
• Weldability

Controlled-atmosphere heat treatment reduces oxide scale and supports bright tube surfaces.

Quality Control and Testing

Goldenman quality control includes:

• Raw-material certificate verification
• Heat-number traceability
• Chemical-composition testing
• Heat-treatment monitoring
• Tensile testing
• Yield-strength testing
• Elongation testing
• Hardness testing
• Flattening testing
• Drift-expansion testing
• Flaring testing
• Bend testing
• Outside-diameter inspection
• Inside-diameter inspection
• Wall-thickness inspection
• Eccentricity inspection
• Ovality inspection
• Straightness inspection
• Length inspection
• Surface-roughness inspection
• Visual-surface inspection
• Eddy-current inspection
• Ultrasonic inspection
• Leak-tightness testing
• Coating inspection
• Marking verification
• Final visual inspection

Nondestructive Examination

Available NDE methods include:

• Eddy-current testing
• Ultrasonic testing
• Magnetic-flux-leakage testing
• Magnetic-particle inspection
• Leak-tightness testing
• Visual and dimensional inspection

NDE detects:

• Longitudinal imperfections
• Transverse imperfections
• Surface cracks
• Internal discontinuities
• Laminations
• Wall-thickness variation
• End-area defects

Dimensional Inspection

Dimensional inspection covers:

• Outside diameter
• Inside diameter
• Wall thickness
• Eccentricity
• Ovality
• Straightness
• Total runout
• Length
• End squareness
• Chamfer
• Surface roughness
• Machining allowance

Coordinate-measuring equipment, bore gauges, air gauges and laser measuring systems are used for critical precision dimensions.

Surface Cleanliness

Hydraulic- and pneumatic-system tubes are cleaned to remove:

• Drawing lubricant
• Steel particles
• Abrasive residue
• Scale
• Dust
• Moisture
• Machining chips

Clean tubes are supplied with sealed ends or protective caps.

Surface Protection

Available protective systems include:

• Rust-preventive oil
• Phosphate and oil
• Black oxide
• Zinc plating
• Zinc plating with passivation
• Temporary wax coating
• VCI wrapping
• Project-specific coating

Surface protection is selected from storage duration, shipping method, forming operation, welding method and end-use environment.

Common Failure and Procurement Risks

Incorrect Grade Equivalence

ST37, St 35, E235 and ASTM 1020 are not automatically interchangeable without reviewing the complete standard, chemistry, delivery condition and mechanical properties.

Missing Delivery Condition

Ordering only “E355 Tube” is incomplete.

E355 +C, +SR and +N have substantially different strength, elongation and machining behavior.

OD Controlled but ID Uncontrolled

A tube ordered only by OD and wall thickness may not provide the tight finished bore needed for a hydraulic cylinder.

Insufficient Machining Allowance

An undersized machining allowance can prevent the bore from reaching the required finished ID and surface condition.

Excessive Machining Allowance

Excessive stock increases boring time, tool wear, material waste and production cost.

Residual-Stress Distortion

Cold-drawn hard tubes can move during splitting, deep cutting or asymmetric machining.

Stress-relieved or normalized tubes reduce this risk.

Wrong Surface Condition

A black cold-drawn surface, bright annealed surface and phosphated hydraulic surface have different downstream processing behavior.

Uncontrolled Straightness

A tube that meets a general commercial straightness limit may still be unsuitable for a long-stroke hydraulic cylinder or rotating roller.

Product Marking

Each tube bundle or individual tube is identified with:

• Goldenman identification
• Product standard
• Steel grade
• Delivery condition
• Outside diameter
• Inside diameter or wall thickness
• Length
• Heat number
• Batch number
• Manufacturing method
• Inspection-document type
• Surface condition
• Manufacturing date

Individual full-length marking is available for project and traceability requirements.

Product Documentation

The documentation package includes:

• Certificate of Conformity
• Product datasheet
• Material Test Certificate
• EN 10204 2.2 certificate
• EN 10204 3.1 certificate
• EN 10204 3.2 certificate
• Chemical-composition report
• Heat-treatment record
• Mechanical-property report
• Hardness report
• Flattening-test report
• Flaring-test report
• Dimensional inspection report
• Straightness inspection report
• Surface-roughness report
• Eddy-current-test report
• Ultrasonic-test report
• Coating inspection report
• Heat and batch traceability list
• Precision-cutting report
• Packing list
• Third-party inspection report

Packaging

Packaging options include:

• Steel-strapped bundles
• Hexagonal bundles
• Wooden crates
• Individual protective sleeves
• Plastic end caps
• VCI paper
• Waterproof wrapping
• Internal separators
• Machined-end protectors
• Export seaworthy packaging

Bright, honed and zinc-coated tubes receive additional surface protection against impact, scratching and moisture.

Frequently Asked Questions

What is Cold Drawn Seamless Steel Tube?

It is a seamless steel tube that undergoes one or more cold-drawing passes to improve dimensional accuracy, surface quality and mechanical properties.

Is this the same as ASTM A106 Pipe?

No.

ASTM A106 is a seamless pressure-pipe standard for high-temperature service.

This page covers precision mechanical tubing under EN 10305-1 and ASTM A519.

Is this an API 5L Line Pipe?

No.

API 5L is used for pipeline transportation.

Cold Drawn Precision Tube is used primarily for machinery, cylinders and precision components.

What sizes are available?

The standard commercial range covers:

• 4–260 mm outside diameter
• 0.5–25 mm wall thickness

ASTM A519 project sizes extend to 325 mm OD.

What is the difference between E235 and E355?

E235 provides lower strength with greater formability.

E355 provides higher yield and tensile strength for heavily loaded mechanical components.

What is the difference between E355 +C and E355 +N?

E355 +C is cold-drawn hard and has higher tensile strength but lower elongation.

E355 +N is normalized and provides more balanced strength, ductility, weldability and forming performance.

Which condition is best for machining?

+C provides high strength and dimensional stability for straightforward machining.

+SR reduces residual stress and is preferred for deep machining, splitting, honing and components susceptible to distortion.

Which condition is best for bending?

+A and +N provide greater ductility for bending and forming.

What is ST52 tube?

ST52 is a legacy German material reference commonly associated with the modern E355 strength class.

A new order should specify EN 10305-1 E355 and the required delivery condition.

Is ST37 the same as E235?

ST37 is an older general commercial reference.

Precision-tube replacement requires confirmation of the original standard, but E235 is the common modern precision-tube purchasing grade for the corresponding lower-strength class.

What ASTM grades are available?

Available ASTM A519 grades include:

• 1010
• 1020
• 1026
• 1035
• 1045
• 4130
• 4140
• 8620

Which grade is commonly used for hydraulic cylinders?

E355 +SR and ASTM A519 Grade 1026 are commonly used for hydraulic-cylinder barrels and machined cylinder components.

Can tubes be supplied ready to hone?

Yes.

Ready-to-Hone Tubes are supplied with controlled bore stock for final honing.

Are finished honed tubes available?

Yes.

Honed and skived roller-burnished cylinder tubes are available with controlled ID, bore roughness and length.

Can OD and ID both be controlled?

Yes.

Tubes can be ordered by OD × ID with specified tolerances and concentricity.

Are fixed lengths available?

Yes.

Random, approximate, exact and precision-cut lengths are available.

Are zinc-coated tubes available?

Yes.

Zinc-plated and passivated hydraulic tubes are available, together with phosphated, oiled, black and bright surfaces.

Can the tube be supplied machined?

Yes.

Available services include cutting, turning, boring, honing, drilling, milling, threading, grooving, chamfering and end forming.

Information Required for Quotation

Please provide:

• EN 10305-1 or ASTM A519
• Steel grade
• Delivery condition
• Outside diameter
• Inside diameter
• Wall thickness
• OD tolerance
• ID tolerance
• Wall-thickness tolerance
• Eccentricity limit
• Ovality limit
• Straightness requirement
• Surface-roughness requirement
• Random or fixed length
• Length tolerance
• Ready-to-hone or finished bore
• Honed or skived roller-burnished bore
• Final bore diameter
• Machining allowance
• Surface condition
• Internal cleanliness
• Zinc-coating requirement
• Phosphating requirement
• Cutting requirement
• Machining requirement
• Heat-treatment requirement
• NDE requirement
• Inspection-certificate type
• Third-party inspection
• Required quantity
• Destination country
• Delivery schedule

Request a Technical Quotation

Goldenman supplies Cold Drawn Seamless Precision Tubes for hydraulic cylinders, pneumatic equipment, automotive components, machinery, oilfield equipment and precision-machined tubular parts.

The complete range covers:

• EN 10305-1 E215, E235 and E355
• ASTM A519 1010, 1020, 1026, 1035 and 1045
• ASTM A519 4130, 4140 and 8620 alloy grades
• +C, +LC, +SR, +A and +N conditions
• Outside diameters from 4 to 260 mm
• ASTM A519 project sizes up to 325 mm
• Wall thicknesses from 0.5 to 25 mm
• OD × wall, OD × ID and ID × wall tolerances
• Ready-to-hone, honed and roller-burnished bores
• Cut-to-length and finished machined components

Complete orders are supplied with material traceability, mechanical-property reports, dimensional inspection, NDE records and EN 10204 inspection documentation.

Email: info@goldenman.com