ASTM A519 Carbon Steel Mechanical Tubing — Factory Direct Supplier | Huaxia-Steel

ASTM A519 mechanical tubing is the specification engineers choose when a tube is going to be machined, bored, honed or otherwise turned into a component rather than simply welded into a structure. Unlike structural pipe standards, A519 controls chemistry and mechanical properties tightly so that downstream machining, heat treatment and pressure performance behave predictably. We supply A519 tubing in Grades 1010 through 1045, hot finished and cold drawn, in outside diameters from 10 mm to 610 mm with wall thicknesses to suit your drawing.

Every tube ships with an EN 10204 3.1 mill test certificate showing heat chemistry, tensile results and the relevant dimensional report. Honed and skived ID tube for hydraulic cylinders, DOM-quality cold drawn tube and cut-to-length service are all available, with export packing engineered for long sea transit.

Product Overview

A519 covers seamless carbon and alloy steel mechanical tubing in hot finished (HF) and cold drawn (CD) conditions. Hot finished tube is economical and stress-relieved by nature, ideal for subsequent machining of larger diameters. Cold drawn tube gives tighter OD/ID control, better surface finish and higher strength from work hardening — the standard choice for precision components.

The most common grades are 1018 and 1026 for general machined parts, 1045 where higher core strength and induction hardening are planned, and 4130 where alloy properties justify it (supplied under the same specification’s alloy scope). Grade selection is driven by the part’s strength target and heat treatment route, and we can advise against your drawing before quoting.

Dimensions and Tolerances

Parameter	Range	Tolerance / Note
Outside diameter	10–610 mm	Hot finished ±1%; cold drawn per A519 tables
Wall thickness	1.5–100 mm	±10% standard; tighter on request
ID (honed tube)	40–400 mm	H8–H9, Ra ≤0.4 μm
Length	3–12 m	Random, fixed or cut to ±1 mm
Straightness	≤1 mm/m standard	≤0.5 mm/m honed tube
Ovality	per A519 tables	Reduced on cold drawn precision sizes

For hydraulic cylinder service we supply honed tube (ID tolerance H8/H9, Ra 0.4 μm or better) paired with CK45 or 1045 chrome plated rod so the cylinder set arrives matched — one purchase order, one inspection, one shipment.

Chemical Composition (Grades 1010–1045, heat analysis)

Grade	C	Mn	P max	S max
1010	0.08–0.13%	0.30–0.60%	0.040%	0.050%
1018	0.15–0.20%	0.60–0.90%	0.040%	0.050%
1026	0.22–0.28%	0.60–0.90%	0.040%	0.050%
1045	0.43–0.50%	0.60–0.90%	0.040%	0.050%

Sulfur can be restricted to 0.030% or lower on request for improved impact properties and cleaner machining of critical parts. All heats are fully killed with fine grain practice available as a supplement.

Mechanical Properties

Condition	Grade	Tensile (min)	Yield (min)	Elongation
Hot finished	1018	325 MPa	180 MPa	35%
Hot finished	1045	525 MPa	310 MPa	20%
Cold drawn	1018	440 MPa	370 MPa	15%
Cold drawn	1045	625 MPa	530 MPa	12%

Values are the specification minimums for common conditions; actual certificate values run higher. For parts that will be quenched and tempered after machining, we recommend 1045 with a normalized or normalized-and-tempered delivery condition so your heat treatment starts from a uniform structure.

Manufacturing Standards

• ASTM A519/A519M — seamless carbon and alloy steel mechanical tubing (HF and CD conditions).
• ASTM A29/A29M — general requirements governing the bar and tube chemistry practice.
• EN 10204 3.1 — inspection certificate issued for every heat and delivery.
• Related options: E355/ST52 equivalents for European drawings, DOM-quality cold drawn for high-pressure parts.
• Nearest equivalents: EN 10305-1 (precision cold drawn), DIN 2391 (legacy hydraulic tube) — cross-overs supplied with equivalence notes.

Cylinder-grade tube is additionally stress-relieved after honing to hold ID geometry through your machining and assembly operations — a small cost that prevents ovality complaints later.

Applications

• Hydraulic and pneumatic cylinders — honed tube and pressure sleeves.
• Machined bushings, spacers, sleeves and bearing housings.
• Drive shafts, torsion tubes and steering columns.
• High-pressure gas and fluid passages in machinery (proof tested on request).
• Structural tubes requiring guaranteed mechanical properties rather than structural-grade chemistry.

Because A519 certifies the tube’s own tensile and chemistry rather than a structural category, it is the correct specification whenever the finished part’s performance depends on the tube material itself — and the wrong one to substitute with cheaper structural pipe.

Quality Assurance

• EN 10204 3.1 MTC with heat chemistry and mechanical tests for every delivery.
• Dimensional reports: OD, wall, ovality and straightness measured per lot.
• Eddy current or ultrasonic testing on request for critical applications.
• Hydrostatic or proof pressure testing available per drawing requirements.
• Honed tube ID inspection reports: tolerance, surface roughness and straightness.
• Third-party inspection (SGS, BV, TÜV) arranged before shipment on request.

Packaging and Export Shipping

Tubes are bundled with steel strapping, end-capped or plugged, oiled or VCI-wrapped against rust, and tagged per heat. Precision and honed tube ships in individual sleeves or wooden boxes with ISPM 15 compliant timber. Container loading uses dunnage and strapping to keep bundles from shifting; lengths beyond 5.8 m ship in 40 ft open-top or flat-rack units.

We ship FOB, CFR and DAP worldwide with stock sizes available in days and drawn or honed specials in 3–6 weeks. Send your drawing or the OD, wall, grade and length list and we will confirm size availability, quote and lead time within 24 hours.

Hot Finished vs Cold Drawn: Choosing the Condition

Aspect	Hot finished (HF)	Cold drawn (CD)
Dimensional accuracy	Standard (±1% OD)	Tight, per A519 CD tables
Surface finish	Oxidized, scaled	Bright, smooth
Strength	Lower (as-hot values)	Higher (work hardened)
Stress state	Relieved by hot work	Residual stress; stress-relieve for slender parts
Best for	Large OD machining stock	Precision parts, cylinder tube

A practical rule: buy hot finished when the part will be fully machined anyway and size tolerance only affects machining allowance; buy cold drawn when final dimensions, surface or strength depend on the tube as supplied. Cylinder tube, bearing sleeves and precision rollers are cold drawn territory; large-diameter machining blanks for flanges and hubs are hot finished territory.

Honed Tube for Cylinder Service: What to Check

Honed A519 tube is the bore half of a hydraulic cylinder, and its acceptance criteria are geometric: ID tolerance (H8 or H9), surface roughness (Ra 0.4 μm or better), straightness and roundness through the full length. Verify that the honing is done after stress relief — otherwise machining the OD later moves the bore out of tolerance. Our honed tube is stress-relieved post-honing, with ID reports supplied per tube so your cylinder shop assembles against numbers, not hope.

Pairing the bore with the rod matters too: honed ID, piston clearance and the chrome rod’s OD are a matched dimension chain. Supplying tube and rod from one source with one inspection keeps that chain accountable — mixed-source cylinder components shift dimension disputes onto whoever assembled the set, which is usually the buyer.

Machining A519 Tube: Practical Notes

Cold drawn A519 machines beautifully — the work-hardened surface and fine structure give clean chips at productive speeds, comparable to cold drawn bar of the same grade. Hot finished tube’s scaled surface is abrasive to tools on the first passes; either remove scale before machining or expect insert wear and program the roughing pass accordingly. ID scale in hot finished tube is also why critical bore parts start from cold drawn or honed stock.

For parts that will be welded after machining (cylinder ports, bosses), plan the weld sequence around the machined geometry — masking machined bores from spatter and sequencing welds to limit distortion keeps the precision you paid for. These are shop-floor details, but they separate a tubing supplier who understands mechanical applications from one who only knows pipe.

Ordering Workflow and Lead Times

Stock A519 sizes in popular OD/wall combinations ship in days; drawn, honed or tested specials run 3–6 weeks depending on starting tube availability. To quote we need: grade, condition (HF or CD), OD, wall, length and quantity — plus any ID tolerance, testing or packing requirements. Drawings welcome; they resolve ambiguity faster than a specification email thread.

For cylinder manufacturers we support scheduled call-offs against a blanket order: honed tube releases matched to your bore schedule, with ID reports archived per tube so every assembly can be traced to its bore geometry months later.

All ASTM A519 mechanical tubing from Huaxia-Steel ships with EN 10204 3.1 certification, dimensional reports and export packing matched to the precision level of the product. Send your OD, wall, grade and length list — or the drawing — and we will return size availability, firm pricing and lead time within 24 hours.

Frequently shipped A519 configurations include: 1018 CD tube for machined bushings and spacers, 1026 HF tube in larger diameters for hydraulic cylinder bodies, 1045 CD for induction-hardened rollers and shafts, and honed ID tube in 40–320 mm bores for cylinder rebuild programs. Stock covers common combinations; specials are drawn or machined from oversized parent tube with full traceability intact.

If your application sits between grades, tell us the function rather than the specification: a short note on load, temperature and machining scope lets us recommend the grade and condition that meets it at the lowest cost, instead of defaulting to the heaviest option on the drawing.