ASTM B338 GR1 Titanium Tube

ASTM B338 is the standard specification for seamless and welded titanium tubes used in condensers and heat exchangers. GR1 (Grade 1) indicates commercially pure titanium with the lowest oxygen content among titanium grades - 0.18% maximum.

 

Low oxygen content gives GR1 the highest ductility and fracture toughness of any commercially pure titanium grade. This means the tube can be severely bent, flared, rolled into tube sheets, or deep drawn without cracking. Fabricators prefer GR1 when the forming process is aggressive.

 

In terms of corrosion resistance, GR1 performs as well as higher-grade titanium in most chemical and marine environments. It resists pitting and crevice corrosion in seawater and chlorinated brines where 316L stainless steel would fail within months.

 

Many buyers assume higher tensile strength is always better. That is not correct.

Grade	Yield Strength (min)	Key Property	Best Application
GR1	138 MPa	Highest formability	Severe bending, deep drawing, U-bends
GR2	275 MPa	Balanced strength/formability	General purpose, most heat exchangers
GR5 (Ti-6Al-4V)	827 MPa	High strength	Aerospace, structural, not for rolling

 

If your tube will be rolled or expanded after welding, GR1 is often the correct choice. GR2 is stronger but less ductile. GR5 is too hard for tube sheet expansion and significantly more expensive.

 

Do not specify GR5 for heat exchanger tubing unless you have a specific strength requirement. You will pay more and create fabrication problems.

Get Free Sample & Evaluation

 

The table below shows the limits that matter during material receiving inspection. Pay attention to oxygen, iron, and elongation.

Parameter	ASTM B338 GR1 Requirement	Why Buyers Check This
Oxygen (max)	0.18%	Directly affects ductility - lower is better for forming
Iron (max)	0.20%	Excess iron reduces corrosion resistance in acids
Nitrogen (max)	0.03%	High nitrogen causes embrittlement
Carbon (max)	0.08%	Standard impurity limit
Hydrogen (max)	0.015%	High hydrogen leads to hydride formation and cracking
Tensile Strength (min)	240 MPa	Adequate for pressure equipment without over-design
Yield Strength (min)	138 MPa	Low yield = easy expansion and bending
Elongation (min)	24%	Critical for U-bend tubes - below 20% is a red flag
Hardness (HRB max)	70	Soft material = lower machining cost and no stress cracking

 

Buyers in these industries regularly order ASTM B338 GR1:

Shell and tube heat exchangers - cooling with seawater or brackish water

Power plant condensers - resists ammonia and chloride attack

Marine cooling systems - saltwater exposure every cycle

Deep drawn titanium parts - requires extreme ductility

Hydraulic forming - GR1 is the standard grade

Chemical pressure vessels - where crevice corrosion is a known risk

 

If your service fluid contains chlorides above 200 ppm at temperatures above 60°C, 316L stainless steel will eventually pit. GR1 will not.

 

The surface finish of a titanium tube is not just about appearance. It directly affects corrosion resistance, fouling tendency, and installation success. Below are the standard finish options available for ASTM B338 GR1 tubes and when to specify each.

Finish Type	Description	Typical Application	Why Buyers Choose This
As-Drawn (Mill Finish)	Direct from drawing die with residual lubricant and oxide scale	Temporary storage or further processing	Lowest cost. Not for direct service - must be cleaned before use
Pickled	Chemically stripped of oxide scale and contaminants	Heat exchangers, condensers, chemical service	Standard for most buyers. Clean surface, uniform matte appearance, ready for installation
Polished (Mechanical)	Buffed to a smooth, reflective surface	Hygienic applications, food processing, pharmaceutical	Reduces fouling and biofilm growth. Easier to clean
Bead Blasted	Fine glass or ceramic beads create a uniform satin finish	Architectural, marine visible components	Hides handling marks. Good for saltwater exposure
Pickled + Passivated	Pickled followed by acid passivation to maximize oxide layer	High-purity chemical service, semiconductor industry	Maximum corrosion resistance. Removes all surface iron contamination
Emery Rolled	Light mechanical polish from emery cloth rolls	Instrument tubing, hydraulic lines	Smooth surface with excellent tube sheet sealing properties

 

Which Finish Should You Specify?

For standard heat exchanger or condenser service: specify Pickled. This removes the manufacturing oxide scale and leaves a chemically clean surface. Do not accept as-drawn tubes for direct installation - the residual lubricant can contaminate your system and the oxide layer may hide surface defects.

 

For seawater or brackish water cooling: specify Pickled or Pickled + Passivated. The passivation step ensures the maximum protective oxide layer, which reduces the risk of crevice corrosion at tube-to-tubesheet joints.

 

For food, pharmaceutical, or high-purity water: specify Polished or Pickled + Passivated. The smooth surface prevents bacterial attachment and is easier to sanitize.

 

For hydraulic or instrument lines: specify Emery Rolled. The smooth exterior surface provides better sealing with compression fittings compared to pickled or as-drawn finishes.

Discuss Your Project Requirements

 

Mill Test Certificate per EN 10204 Type 3.1 - must show actual oxygen, iron, and hydrogen values

Hydrostatic test report - required for heat exchanger tubes

Eddy current (ET) or ultrasonic (UT) test report per ASTM B338

Dimensional inspection report - OD, wall, length, straightness

Material traceability - each tube stamped with heat number

 

For critical projects, request third-party inspection from SGS, BV, or TÜV before shipment. The cost is small compared to replacing failed tubes in a operating heat exchanger.

 

1. What is the real difference between ASTM B338 GR1 and GR2?
GR1 has lower oxygen (0.18% vs 0.25% max) and lower yield strength (138 MPa vs 275 MPa). GR1 is significantly more ductile and easier to bend without cracking. GR2 is stronger but less formable.

 

2. Can GR1 titanium tube be used in seawater?
Yes. GR1 resists crevice corrosion in seawater up to about 120°C (250°F). Above that temperature, specify GR7 or GR12 for better high-temperature stability.

 

3. Does GR1 require heat treatment after welding?
No. GR1 is not heat-treatable. Proper argon shielding during welding is the only requirement.

 

4. What is the maximum pressure for a GR1 tube?
Depends on OD and wall thickness. For a typical 25.4 mm OD x 1.65 mm wall tube at room temperature, allowable pressure is roughly 1,500 psi per ASME Section VIII. Contact a piping engineer for your specific conditions.

 

5. Is welded GR1 tube acceptable for heat exchangers?
Yes, ASTM B338 allows both seamless and welded-and-drawn (W&D) tubes. Welded tubes are more economical. Seamless is preferred for pressures above 500 psi or where weld seam corrosion is a concern.

 

6. How do you cut GR1 titanium tube correctly?
Use a cold saw with carbide-tipped blades or a band saw with 24 TPI blade. Do not use abrasive cutting wheels - they cause localized overheating and surface contamination.

 

7. Is GR1 titanium magnetic?
No. Titanium is paramagnetic. This matters for applications near sensitive electronics or magnetic resonance equipment.

 

8. What lead time should I expect for ASTM B338 GR1 tubes?
Common sizes (19 mm, 25.4 mm OD) are often stocked and ship within 2–3 weeks. Custom seamless sizes or heavy walls require 6–8 weeks from mill order.

 

9. Can GR1 touch stainless steel or copper alloys in service?
In seawater, titanium is cathodic relative to copper alloys. Direct contact will cause galvanic corrosion of the copper. Use isolating gaskets or coatings. Contact with stainless steel is generally acceptable but avoid crevices.

 

10. What certifications must a GR1 supplier provide?
Minimum: Mill Test Certificate per EN 10204 3.1, hydrostatic test report, and material traceability stamps. For critical service, require third-party inspection (SGS, BV, TÜV).

 

11. Does GR1 titanium tube cost more than 316L stainless?
Yes, the material cost is higher. But total lifecycle cost is often lower because GR1 does not corrode in chloride service. You avoid replacement, downtime, and product loss.

 

12. Can GR1 be used for hydrogen service?
With caution. Titanium can form hydrides above certain temperatures and pressures. Consult a materials engineer for hydrogen service above 80°C or 10 MPa.

 

Specify ASTM B338 GR1 titanium tube when you need:

High ductility for severe cold forming or U-bending

Corrosion resistance in seawater, chlorides, or acidic brines

Light weight compared to stainless steel or copper-nickel alloys

A material that is weldable and does not require post-weld heat treatment

 

Do not specify GR1 when you need:

High strength above 240 MPa tensile - use GR2 or GR5

Maximum hardness or wear resistance - titanium is not a wear-resistant alloy

Lowest possible material cost - use 316L if chlorides are not present

 

For a quote, send your OD, wall thickness, length, and quantity. Include any special requirements such as U-bends, third-party inspection, or surface finish. We will reply with a commercial offer and a sample mill certificate within one business day.

 

Our facility is equipped with dedicated titanium tube production lines, including cold pilger mills, draw benches, and argon-filled annealing furnaces specifically calibrated for commercially pure titanium. For welded tubes, we use automatic TIG welding stations with online eddy current monitoring to detect weld seam defects in real time. Inspection equipment includes a full-spectrum spectrometer for chemical verification, an ultrasonic flaw detector for seamless tubes, and a hydrostatic pressure tester rated to 10,000 psi. All finished tubes pass through a laser micrometer for OD and wall thickness measurement. Our quality lab maintains independent cross-checks on every heat lot, and all inspection equipment is calibrated annually to NIST-traceable standards. This setup allows us to produce ASTM B338 GR1 tubes that consistently meet or exceed the required mechanical and corrosion performance.

Check Today's Stock & Lead Time

 

Hot Tags: astm b338 gr1 titanium tube, China astm b338 gr1 titanium tube manufacturers, suppliers, factory, titanium, titanium pipe tariffs, titanium pipe preferential trade arrangements, titanium Gr2 alloy plate, titanium pipe hazardous media compatibility, titanium pipe creep resistance, titanium pipe valves