Titanium & Titanium Alloy Hollow Bars: Lightweight Strength in Harsh Environments
Table of Contents:
During deepwater oil exploration, a Ti-6Al-4V OCTG string experienced crevice corrosion in chloride-rich brine, leading to localized pitting and operational failure issues plaguing alloys without stable passivation. Titanium hollow bars excel here with self-healing oxide films and superior strength-to-weight for subsea and chemical demands.
Specifications and Standards
Titanium hollow bars meet ASTM B348/ASME SB348 (bars/billets), B861 (seamless pipe extended), AMS 4928, UNS R50400 (Gr2), R56407 (Gr5), DIN 3.7035 (Gr2), 3.7164 (Gr5), EN 10204-3.1 certs. OD 20-300mm, ID 10-250mm, tolerances per ASTM for machining stock.
NACE MR0175 compliant for sour service in oil & gas.
Specifications by Grade – Rod and bar
A specification is written for a product form. The standards below are the ones that cover rod and bar; the plate, bar and tube specifications for these grades are different documents and are listed on their own pages.
| Grade | UNS | Rod and bar specification |
|---|---|---|
| Grade 1 | R50250 | ASTM B348 |
| Grade 2 | R50400 | ASTM B348 |
| Grade 5 | R56400 | ASTM B348 |
| Grade 7 | R52400 | ASTM B348 |
| Grade 9 | R56320 | ASTM B348 |
| Grade 11 | R52250 | ASTM B348 |
| Grade 12 | R53400 | ASTM B348 |
| Grade 23 | R56407 | ASTM B348 |
| Ti-6-2-4-2 | R54620 | AMS 4975 / MIL-T-9047G |
| Ti-6-6-2 | R56620 | AMS 4971 / AMS 4978 |
| Ti-5-2-4-4 | R58650 | Mill specification |
| Ti-8-1-1 | R54810 | AMS 4972 |
| Ti-6Al-7Nb | R56700 | ASTM F1295 / ISO 5832-11 |
Specifications and Standards
Titanium hollow bars meet ASTM B348/ASME SB348 (bars/billets), B861 (seamless pipe extended), AMS 4928, UNS R50400 (Gr2), R56407 (Gr5), DIN 3.7035 (Gr2), 3.7164 (Gr5), EN 10204-3.1 certs. OD 20-300mm, ID 10-250mm, tolerances per ASTM for machining stock.
NACE MR0175 compliant for sour service in oil & gas.
Equivalent Grades
| Grade | UNS | DIN | AMS |
|---|---|---|---|
| Unalloyed Gr2 | R50400 | 3.7035 | 4902 |
| Gr5 (Ti-6Al-4V) | R56407 | 3.7164 | 4928 |
| Gr23 (Ti-6Al-4V ELI) | R56407 | 3.7235 | 4911 |
Product Forms and Availability
Hollow (trepanned/extruded), seamless pipe forms; OD/ID 20x10 to 300x250mm, straights 2-6m. Annealed ASTM 5 alpha structure. Nickel alloy hollow bars complement for higher-temp corrosion.
Chemical Composition
Gr2: Ti bal., O 0.25% max, Fe 0.30% max, C 0.08% max. Gr5: Al 5.5-6.75%, V 3.5-4.5%, O 0.20% max, Fe 0.40% max. Low interstitials ensure ductility.
| Ti | Al | V | Fe | O |
|---|---|---|---|---|
| Bal | 5.5-6.75 | 3.5-4.5 | 0.40 max | 0.20 max |
Mechanical and Physical Properties
Gr5: Tensile 1170 MPa, yield 1100 MPa, 10% elong., hardness 379 HB, modulus 114 GPa. Density 4.43 g/cm³ (60% steel), CTE 8.6 µm/m°C, cond. 6.7 W/mK. Hollow cuts weight 40% vs solid.
Bio-compatible Gr23 variant boosts fatigue toughness.
Applications by Industry
Chemical Processing
Reactor vessels, agitators resist chlorides/acids better than Hastelloy at lower cost.
Oil & Gas
Drilling risers, OCTG prevent SCC in H2S.
Marine
Seawater desalination, propeller shafts; immune to pitting and crevice attack in seawater.
Pharma
Implantable devices, sterile piping (Gr23).
Power Generation
Condenser tubes, erosion shields.
Comparison with Common Grades
| Property | Ti Gr5 | SS316 | Inconel 625 |
|---|---|---|---|
| Density (g/cm³) | 4.43 | 8.0 | 8.44 |
| Tensile (MPa) | 1170 | 515 | 827 |
| Marine CREV | Excellent | Pitting | Good |
| Cost/kg | High | Low | Higher |
| Max Temp (°C) | 400 | 870 | 980 |
Ti wins on weight/corrosion for marine/offshore.
EEAT Signals: Quality Assurance
ASTM ultrasonic per B348, PMI, hydrogen embrittlement tests, AD2000 certs, MTRs for PED 2014/68/EU. Export-ready from Mumbai.
Frequently Asked Questions
What standards for titanium hollow bars?
ASTM B348 (Gr2 R50400, Gr5 R56407), DIN 3.7035/3.7164, AMS 4928. Cover bars/billets; tolerances for machining. NACE for sour gas.
Properties of Ti-6Al-4V Gr5 hollow bars?
Tensile 1170 MPa, yield 1100 MPa, 10% elong., density 4.43 g/cm³, modulus 114 GPa. 60% lighter than steel; oxide passivation.
Why titanium hollow bars for oil & gas?
Resist crevice/SCC in brine/H2S; hollow saves 40% weight/machining. Beats SS316 in marine; Gr5 strength rivals alloys.
Sizes of titanium alloy hollow bars?
OD 20-300mm, ID 10-250mm, 2-6m lengths. Gr2/5 stock; titanium hex bars for solid. Trepanned seamless.
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Titanium hollow bars offer unmatched corrosion resistance and lightness, validated by standards for marine, oil, and chemical OEMs. Ready to specify titanium hollow bars for your lightweight, durable components?