What Is ASTM B234 Aluminum Heat Exchanger Tubes - Knowledge

1. What Is ASTM B234?

ASTM B234 is the US standard for aluminum and aluminum-alloy drawn seamless round tubes in straight lengths, used in surface condensers, evaporators, and heat exchangers. The current active version is ASTM B234-17(2025); the metric version is ASTM B234M-17(2025).

Two points matter if you are buying these tubes:

"Drawn seamless" means the tube is cold-drawn from an extruded hollow ingot. It has no welded seam.

B234 is specifically a heat-exchanger tube standard. If your job is general-purpose aluminum tube, that is ASTM B210. If you need extruded tube or pressure pipe, that is a different standard (see section 9).

GNEE is an aluminum heat exchanger tube supplier in China. We quote and supply ASTM B234 tubes in 3003 and other alloys. Send us your size, alloy, and quantity and we will come back with a price.

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2. Which Alloys Are Covered by ASTM B234?

B234 lists these materials: 1060, 3003, Alclad 3003, 5052, 5454, 6061.

Alloy	Family	What It Is	Common Use in Heat Exchange
1060	1xxx	Pure aluminum, 99.6% min, high thermal conductivity	Tubes where strength is not the main requirement
3003	3xxx	Manganese alloy, good formability and corrosion resistance	The most common alloy for heat exchanger tubes
Alclad 3003	3xxx	3003 core with a 7072 cladding layer	Tubes exposed to corrosive cooling water
5052	5xxx	Magnesium alloy, stronger than 3003	Higher-pressure or marine-type service
5454	5xxx	Magnesium alloy, medium-high strength	Industrial plant heat exchangers
6061	6xxx	Heat-treatable alloy, highest strength on this list	Where the tube also has to carry some load

3003 is the alloy we supply most for heat exchangers. It gives a good balance of formability, corrosion resistance, and strength, and it bends and flares well during assembly.

3. Chemical Composition (ASTM B234 Table 1)

Composition limits in percent, maximum unless shown as a range.

Alloy	Si	Fe	Cu	Mn	Mg	Cr	Zn	Ti	Al
1060	0.25	0.35	0.05	0.03	0.03	–	0.05	0.03	99.60 min
3003	0.60	0.70	0.05–0.20	1.0–1.5	–	–	0.10	–	remainder
Alclad 3003	3003 core, clad with 7072 alloy
5052	0.25	0.40	0.10	0.10	2.2–2.8	0.15–0.35	0.10	–	remainder
5454	0.25	0.40	0.10	0.50–1.0	2.4–3.0	0.05–0.20	0.25	0.20	remainder
6061	0.40–0.80	0.70	0.15–0.40	0.15	0.8–1.2	0.04–0.35	0.25	0.15	remainder

Other elements: 0.05% max each, 0.15% max total. The actual heat chemistry is shown on the mill test certificate (MTC) we ship with the material.

6061 aluminum pipe

4. Tempers and Mechanical Properties (ASTM B234M Table 2)

The tempers used under B234: 3003 in H14 and H25, 5052 and 5454 in H32 and H34, 6061 in T4 and T6. Because 3003 is not heat-treatable, its strength comes from cold drawing. H14 is stronger than the annealed O condition but still forms well.

Minimum tensile properties from B234M-17, Table 2:

Alloy	Temper	Wall Thickness (mm)	Tensile Strength Min (MPa)	Yield Strength Min (MPa)	Elongation Min % (full-section / cut-out)
1060	H14	0.25–5.00	85	70	–
3003	H14	0.25–0.63	140	115	3 / –
3003	H14	0.63–1.20	140	115	5 / 3
3003	H14	1.20–5.00	140	115	8 / 4
3003	H25	0.25–5.00	150	130	–
Alclad 3003	H14	0.25–0.63	135	110	–
Alclad 3003	H14	0.63–1.20	135	110	5 / 3
Alclad 3003	H14	1.20–5.00	135	110	8 / 4
Alclad 3003	H25	0.25–5.00	145	125	–
5052	H32	0.25–5.00	215	160	–
5052	H34	0.25–5.00	235	180	–
5454	H32	0.25–1.20	250	180	– / 5
5454	H32	1.20–5.00	250	–	– / 8
5454	H34	0.25–1.20	270	200	– / 4
5454	H34	1.20–5.00	270	200	– / 6
6061	T4	0.25–1.20	205	110	16 / 14
6061	T4	1.20–5.00	205	110	18 / 16
6061	T6	0.25–1.20	290	240	10 / 8
6061	T6	1.20–5.00	290	240	12 / 10

Notes: values are minimums from B234M-17. A dash means the standard states no value for that combination. For design calculations, use the certified values on the actual MTC, not numbers from a website.

5. How ASTM B234 Tubes Are Made

The manufacturing route is:

Hollow extrusion ingot → extrusion → cold drawing → final sizing → testing → inspection → packing

Cold drawing gives accurate outside diameter and wall thickness and a clean surface. For a heat exchanger, OD fit in the tube sheet and uniform wall both matter, which is why drawn seamless tube is specified.

Cold Drawn Aluminum Tubing Manufacturer

6. Dimensions and Tolerances

What you normally specify when ordering:

Outside diameter (OD)

Wall thickness (WT)

Length

Alloy and temper

Quantity

Surface and end condition

Example order line: 3003-H14, ASTM B234, OD 25.4 mm × WT 1.2 mm × 6000 mm, straight length.

Tolerances follow ANSI H35.2, the tolerance standard that B234 refers to, plus anything agreed in your purchase spec. If your OD or wall tolerance is tight, tell us the values you need and we confirm feasibility before production.

Dimensional checks that matter: OD (must fit the tube sheet), wall thickness (pressure and weight), length, ovality, straightness, and surface condition.

7. Testing and Certification

B234 requires three tests on the tube: tension, leak, and expansion.

Tension test – confirms tensile strength, yield strength, and elongation.

Leak test – checks tube integrity for fluid service.

Expansion test – checks that the tube can be flared or expanded without cracking.

We can also add dimensional inspection, chemical analysis (lab test), and third-party inspection before shipment (SGS, BV, TUV) when your contract asks for it.

Every shipment comes with an MTC (mill test certificate) covering alloy, temper, heat/lot number, chemical composition, mechanical properties, dimensions, and test results. Keep the MTC with the material for traceability.

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8. Where ASTM B234 Tubes Are Used

Common, proven applications for drawn seamless aluminum heat exchanger tubes:

Surface condensers in power stations (condensing steam)

Evaporators and condensers in refrigeration and HVAC equipment

Shell-and-tube heat exchangers in industrial plants (oil cooling, air compressor cooling, process water cooling)

Oil coolers and intercoolers

Other fluid-to-fluid or fluid-to-air cooling duties

If your application is different, tell us the fluid, working temperature, and pressure. We can check whether the alloy and temper you picked are the right fit.

9. ASTM B234 vs B210 vs B221 vs B241

These four standards are easy to mix up. Here is the difference:

Standard	Product	Main Purpose
ASTM B234	Drawn seamless round tube, straight lengths	Condensers, evaporators, heat exchangers
ASTM B210	Drawn seamless tube	General-purpose and pressure applications
ASTM B221	Extruded tube and profiles	General extruded products
ASTM B241/B241M	Seamless pipe and seamless extruded tube	Pressure applications

Not sure which standard your project needs? Send us your drawing or specification and we will tell you.

6061 T6 SEAMLESS PIPE Loading photo 30

GNEE is an ASTM B234 tube manufacturer and supplier in China. We supply 3003 and other alloys for heat exchanger and condenser production, with export packing, mill test certificates, and competitive prices and lead times. Common sizes can be shipped from stock or scheduled on short lead time; larger or custom sizes are produced to order. Samples and trial orders are available for most sizes.

Send your specification to GNEE and we will come back with a quotation. Tell us the size, quantity, and destination port, and we will reply with price, lead time, and packing details.

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11. FAQ

Is ASTM B234 suitable for aluminum heat exchanger tubes? Yes. B234 covers drawn seamless aluminum-alloy round tubes for surface condensers, evaporators, and heat exchangers.

Which alloys are available under ASTM B234? 1060, 3003, Alclad 3003, 5052, 5454, and 6061 as finished tubes. 7072 is used only as the cladding layer on Alclad 3003.

Is 3003 good for heat exchangers? Yes. It is the most common alloy for this application because it forms well, resists corrosion, and has moderate strength.

What tests does ASTM B234 require? Tension, leak, and expansion tests. Additional inspection can be agreed with the buyer.

Can ASTM B234 tubes be supplied with an MTC? Yes. Every shipment includes an MTC with chemical composition and mechanical property results for the supplied heat/lot.

What is the minimum order? For common sizes we can discuss a trial order of less than one container. For most projects, one container or more gives the best price. We confirm MOQ and lead time in the quotation.

Conclusion

ASTM B234 is the standard to name when you are buying drawn seamless aluminum tubes for condensers, evaporators, and heat exchangers. The details that make a clean order: standard, alloy, temper, OD, wall thickness, length, quantity, testing, and certificate.

When you are ready, send your specification to GNEE for an aluminum heat exchanger tube quotation. We will check the size against the standard, confirm what we can supply, and give you a clear price with lead time.