Gr4 (UNS R50700) Supplier | Bar, Tube, Plate - Hangbo Alloy

Shanghai Hangbo Alloy Group Co., Ltd. is an ISO 9001:2015 certified manufacturer and global supplier of premium Titanium Grade 4 (Pure Titanium, UNS R50700) round bars, seamless and welded tubes, plates, sheets, wires and forgings. The highest-strength member of the commercially pure (CP) titanium family, Grade 4 delivers 550 MPa minimum tensile strength with the full corrosion resistance, biocompatibility and weldability inherent to unalloyed titanium. It is the engineering standard for medical implants, chemical processing equipment, heat exchangers and high-load marine fasteners.

Standards & Specifications

• ASTM B265 — Strip, Sheet and Plate (also ASME SB-265)
• ASTM B348 — Bars and Billets (also ASME SB-348)
• ASTM B367 — Castings / ASTM B381 — Forgings
• ASTM B861 (seamless tube) / ASTM B862 (welded tube)
• UNS R50700 / ISO 5832-2 (surgical implants) / EN 10204 3.1 / 3.2 mill certificates

Precise ASTM Chemical Composition (%)

Physical & Mechanical Properties (Annealed, Minimum)

Depth Characteristics

1. Strongest Pure Titanium: 550 MPa minimum tensile — approaching alloy levels — from purely interstitial (oxygen/iron) strengthening with zero alloying additions.
2. 100% Biocompatible: Compliant with ISO 5832-2 for surgical implants; the inert TiO₂ surface integrates with human bone without allergic or toxic response.
3. Outstanding Corrosion Resistance: Immune to seawater, chlorides and most oxidizing acids — the passive film self-heals instantly if scratched.
4. Excellent Weldability: CP microstructure welds cleanly by TIG/plasma/laser with no preheat and no post-weld heat treatment for most sections.
5. High Specific Strength: At 4.51 g/cm³, Gr4 outperforms 316L stainless on strength-to-weight while eliminating galvanic and pitting failures.
6. Proven in Medical & Marine Service: Decades of use in bone screws, dental posts, ship fasteners and chemical pumps with near-zero corrosion-related failures.

Manufacturing Process — Sponge Selection, VAR / EB Melting

Grade 4 starts with Kroll-process titanium sponge selected for its higher interstitial content — the 0.40% max oxygen and 0.50% max iron provide the intrinsic strengthening that defines the grade. Sponge lots are blend-computed and chemistrized before compaction. The electrodes are melted 1–2 times in a Vacuum Arc Remelting (VAR) furnace, with optional Electron Beam Cold Hearth (EBCHM) refining for medical-implant and tube stock. Ingots are forged and rolled in the alpha field, then annealed at 650–760°C to restore ductility after working. Medical-grade material is finished to ISO 5832-2 with tight chemistry control and full implant-grade traceability.

Testing & Inspection — PMI / UT

• PMI (Positive Material Identification): 100% XRF / OES verification of Fe and Ti on every bar, plate and tube; interstitial O/N/H verified by inert-gas fusion analysis per heat.
• UT (Ultrasonic Testing): Full-length ultrasonic examination of billet/bar (ASTM E2375 / E213), plate (ASTM E114) and tube (ASTM E213 + eddy current per ASTM E426).
• Mechanical Verification: Tensile, yield and elongation per ASTM E8, plus hardness; medical lots additionally verified per ISO 5832-2 requirements.
• Microstructure & Dimensional: Metallographic grain-size control, liquid-penetrant inspection, and full dimensional checks to mill tolerance.
• EN 10204 3.1 / 3.2 certificates and third-party inspection (SGS, BV, TÜV) available.

Application Scenarios — Medical / Marine / Chemical

• Medical & Surgical: Bone screws, plates, dental implants, surgical instruments and prosthetic components per ISO 5832-2.
• Marine Engineering: High-load fasteners, propeller shafts, seawater pump shafts and offshore hardware requiring strength beyond Grades 2/3.
• Chemical Processing: Heat-exchanger tubes, reactor liners, valve and pump components in chloride and oxidizing acid service.
• Desalination & Power: Condenser tubes and brine-handling equipment with immunity to chloride pitting and erosion-corrosion.
• Industrial & Sporting: High-strength wire, springs, bicycle components and electrochemical anodes for impressed-current systems.

7+ Professional FAQs

1. What is the UNS number of Titanium Grade 4?
Titanium Grade 4 (pure titanium, highest-strength CP grade) is UNS R50700, covered by ASTM B265 (sheet/plate), B348 (bar/billet), B367 (castings) and B381 (forgings).

2. How does Grade 4 differ from Grades 1–3?
All CP grades share the same unalloyed chemistry; Grade 4 carries the highest allowed oxygen (0.40%) and iron (0.50%), giving the highest strength — 550 MPa tensile vs 240 MPa for Grade 1.

3. Is Grade 4 suitable for medical implants?
Yes — it meets ISO 5832-2 and is widely used for bone screws, plates and dental implants where high strength and full biocompatibility are required together.

4. Can Grade 4 be welded?
Yes — like all CP grades it welds readily by TIG/GTAW, plasma and laser with inert shielding; no preheat or post-weld treatment is needed for most sections.

5. What is the maximum service temperature?
Continuous service to ~315°C (600°F) in corrosive media; short-term exposure to 425°C is acceptable for non-structural duty.

6. Is Grade 4 corrosion resistant in seawater?
Fully immune — the passive TiO₂ film gives complete protection against seawater, chlorides and pitting, verified over decades of marine service.

7. Which melting routes are used for Grade 4?
Single or double VAR melting with optional EBCHM refining; implant-grade material is produced with full chemistry traceability from sponge to finished product.

8. What forms does Hangbo supply in Grade 4?
Round bar, plate, sheet, welded/seamless tube, wire and forgings — all with PMI-verified chemistry and complete EN 10204 documentation.

Supply List

• Round Bar: Φ6mm – Φ350mm, peeled/ground, annealed
• Plate / Sheet: Thickness 1mm – 80mm, ASTM B265
• Welded Tube / Pipe: OD 19mm – 610mm, ASTM B862
• Seamless Tube: OD 6mm – 219mm, ASTM B861
• Wire / Forgings: Implant-grade wire, fasteners and custom components

Contact Hangbo Alloy for Certified Titanium Gr4

Need certified Titanium Gr4 (UNS R50700) bar, tube or plate for medical, marine or chemical applications? Contact Shanghai Hangbo Alloy Group for instant quotations, stock availability and mill certificates — quick response within 10 minutes.