Tesco Steel & Engineering manufactures Titanium Grade 1 flanges — commercially pure (CP) titanium, the softest, most ductile and most formable of the CP grades, forged to ASTM B381 Grade F-1 (UNS R50250, DIN 3.7025). At about half the weight of steel, Grade 1 combines low density with outstanding resistance to seawater, chlorides, wet chlorine and oxidising acids — the grade chosen where maximum ductility and corrosion resistance matter. Available in weld neck, slip-on, blind, socket-weld, threaded and lap-joint types to ASME B16.5 / B16.47. Class 150 to 2500, NPS 1/2″ to 24″, PN6 to PN400. ISO 9001:2015 certified. Made in India.
Titanium Grade 1 (ASTM B381 F-1) Flanges
Titanium Grade 1 Weld Neck & Blind Flanges
Tesco Steel & Engineering manufactures Titanium Grade 1 flanges per ASTM B381 and ASME B16.5, in all flange types from weld neck to blind, Class 150 to 2500 — supplied with EN 10204 3.1 / 3.2 certification, PMI and third-party inspection on request. Explore the wider titanium flange range, ASTM B363 Gr 1 titanium fittings, Titanium Grade 2 flanges, and the flange dimension charts.
| Titanium Grade 1 flanges are available in the following specifications: | |
|---|---|
| Material Grade | Titanium Grade 1 (CP Ti) / UNS R50250 / ASTM B381 F-1 / DIN 3.7025 |
| Type | Commercially pure titanium — softest, most ductile CP grade |
| Size | 1/2″ NB to 24″ NB (DN 15 to DN 600); larger to ASME B16.47 |
| Class / Rating | 150#, 300#, 600#, 900#, 1500#, 2500# · 3000#, 6000#, 9000# (socket-weld / threaded) |
| Pressure Ratings | PN 6 – PN 400 (PN6, 10, 16, 25, 40, 64, 100, 160, 250, 320, 400) |
| Schedule / Wall Thickness | STD, XS, XXS, SCH 10, 20, 40, 80 |
| Standards | ASTM B381 (forgings F-1), B348 (bar), B265 (plate); ASME B16.5, B16.47; DIN 3.7025 |
| Flange Types | Weld Neck (WNRF), Slip-On (SORF), Blind, Socket Weld (SWRF), Lap Joint, Threaded / Screwed, Plate, Long Weld Neck, Orifice |
| Flange Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove (T&G) |
| Weld Filler | ERTi-1 (AWS A5.16) commercially pure titanium |
| Testing | PMI, hydrostatic, UT, MT/PT, weld-colour inspection per spec; EN 10204 3.1 / 3.2 |
Grade 1 has the lowest interstitial (oxygen, iron) content of the commercially pure titanium grades, which is why it is the softest and most ductile. Its corrosion resistance comes from the titanium-oxide passive film rather than from alloying.
| Element | Titanium Grade 1 (UNS R50250) |
|---|---|
| Titanium (Ti) | Balance (commercially pure) |
| Oxygen (O) | 0.18% max |
| Iron (Fe) | 0.20% max |
| Carbon (C) | 0.08% max |
| Nitrogen (N) | 0.03% max |
| Hydrogen (H) | 0.015% max |
| Mechanical Property | Titanium Grade 1 |
|---|---|
| Tensile Strength (min) | 240 MPa (35 ksi) |
| Yield Strength 0.2% (min) | 170 MPa (25 ksi) |
| Yield Strength (max) | 310 MPa (45 ksi) |
| Elongation (min) | 24% |
| Density | 4.51 g/cm³ (~56% of steel) |
| Modulus of Elasticity | ~103 GPa |
| Max Continuous Service Temp | ~300 °C |
| Standard | Titanium Grade 1 Designation |
|---|---|
| UNS (USA) | R50250 |
| ASTM (forgings / flanges) | B381 F-1 (also B348 Gr 1 bar, B265 Gr 1 plate) |
| EN / DIN (Europe) | 3.7025 / Ti1 |
| Werkstoff | 3.7025 |
| JIS (Japan) | Class 1 (Type 1) |
| Common name | CP Titanium Grade 1 |
Titanium Gr 1 Weld Neck (WNRF)
Titanium Gr 1 Slip-On (SORF)
Titanium Gr 1 Blind (BFF)
| Flange Type | Description & Titanium-Gr-1-Specific Use |
|---|---|
| Weld Neck (WNRF) | Tapered hub butt-welded to pipe for high-integrity seawater and wet-chlorine lines; weld with ERTi-1 filler under full inert shielding. |
| Slip-On (SORF) | Fillet-welded over the pipe; light, ductile connection for marine and chemical secondary piping. |
| Blind (BFF) | Seals pipe ends and vessel nozzles in seawater, chlor-alkali and oxidising-acid service. |
| Socket Weld (SWRF) | Small-bore (1/2″–2″) instrument and chemical-injection connections. |
| Lap Joint (LJRF) | Used with a titanium stub end where frequent dismantling is needed; economises on titanium in the backing ring. |
| Threaded (TRFF) | Internal NPT/BSP threads for non-welded connections in corrosive utility service. |
| Long Weld Neck / Orifice / Plate | Nozzle, flow-metering and plate flanges in Grade 1 for marine and chemical-process duty. |
| Property | Grade 1 (R50250) | Grade 2 (R50400) | Grade 5 / Ti-6Al-4V (R56400) | Grade 7 (R52400) |
|---|---|---|---|---|
| Type | CP Ti (lowest interstitials) | CP Ti (workhorse) | Alpha-beta alloy | CP Ti + Palladium |
| Tensile (min) | 240 MPa | 345 MPa | 895 MPa | 345 MPa |
| Ductility / formability | Highest | High | Lower | High |
| Seawater / chlorides | Excellent | Excellent | Excellent | Excellent |
| Reducing acids (HCl, H₂SO₄) | Limited | Limited | Limited | Good (Pd) |
| Flange spec | ASTM B381 F-1 | ASTM B381 F-2 | ASTM B381 F-5 | ASTM B381 F-7 |
| Best For | Max ductility, forming, anodes, cladding | General corrosion / marine workhorse | High strength, aerospace, fasteners | Reducing acid & chemical service |
Immune to pitting and crevice corrosion in seawater and chloride brines far beyond stainless — ideal for marine, offshore and desalination.
Excellent in wet chlorine, chlorate, hypochlorite and oxidising acids (e.g. nitric) — the standard for chlor-alkali and bleaching.
Density ~4.51 g/cm³ — about half of steel, cutting weight in marine, offshore and aerospace assemblies.
Lowest interstitials give superb formability, deep-drawing and cold-working ability — ideal for forming, anodes and explosive cladding.
| Industry | Typical Application |
|---|---|
| Chlor-Alkali | Wet chlorine, chlorate and hypochlorite piping; cell and anode connections |
| Desalination & Seawater | Seawater feed, brine and RO piping; heat-exchanger and condenser nozzles |
| Marine & Offshore | Seawater cooling and firewater systems where weight and chloride resistance matter |
| Chemical Processing | Oxidising acids (nitric), organic acids and chloride salt solutions |
| Pulp & Paper | Bleach plant piping (chlorine dioxide / hypochlorite) |
| Power Generation | Seawater-cooled surface condensers and feed connections |
| Electroplating & Anodes | Anode baskets and connections exploiting Grade 1's formability |
Forged from certified commercially pure titanium with PMI verification — full chemistry and interstitial control on the MTC.
WNRF, SORF, blind, socket-weld, threaded, lap-joint, LWN, orifice and plate — in RF, FF, RTJ and T&G faces.
Welded under full inert-gas shielding with weld-colour inspection to guarantee uncontaminated, ductile joints.
EN 10204 3.1 / 3.2 MTC, heat/lot traceability, hydrostatic and third-party inspection on request.
Titanium Grade 1 flange prices reflect titanium sponge/market rates plus size, pressure class, flange type and quantity — titanium carries a premium over stainless but offers unmatched seawater/chloride life and weight saving. Tesco Steel & Engineering offers competitive ex-works pricing from Mumbai with full export documentation and material traceability. Click Ask for Quote or message us on WhatsApp at +91 92233 66922 with flange type, size (NB), pressure class, quantity and documentation requirements.
Q1. What is a Titanium Grade 1 flange?
A Titanium Grade 1 flange is a pipe flange made from commercially pure (CP) titanium Grade 1 (UNS R50250) — the softest, most ductile and most formable of the CP titanium grades, with the lowest oxygen and iron content. Forged flanges are supplied to ASTM B381 Grade F-1 and machined to ASME B16.5 / B16.47. Grade 1 is lightweight (about half the density of steel) and offers outstanding resistance to seawater, chlorides, wet chlorine and oxidising acids.
Q2. What is the difference between Titanium Grade 1 and Grade 2 flanges?
Both are commercially pure titanium with the same excellent corrosion resistance, but they differ in strength and ductility. Grade 1 has lower oxygen/iron, so it is softer, more ductile and more formable, with lower strength (tensile ~240 MPa min). Grade 2 is the most widely used CP grade, with higher strength (tensile ~345 MPa min) and slightly lower ductility. Choose Grade 1 where maximum formability or deep-drawing/cladding is required; choose Grade 2 as the general-purpose workhorse.
Q3. What standard covers Titanium Grade 1 flanges?
Forged titanium flanges are supplied to ASTM B381 Grade F-1 for Grade 1 (UNS R50250). Related product standards are ASTM B348 (bar/billet) and ASTM B265 (plate/sheet). Flange dimensions follow ASME B16.5 (1/2″–24″ NB) or ASME B16.47 for larger diameters. The European equivalent is DIN 3.7025 / Werkstoff 3.7025.
Q4. What is the corrosion resistance of Titanium Grade 1?
Titanium Grade 1 forms a stable, self-healing titanium-oxide passive film that gives outstanding resistance to seawater, brackish water, chlorides, wet chlorine, chlorate and hypochlorite, oxidising acids (such as nitric acid), and most organic acids and chloride salt solutions. It resists pitting and crevice corrosion in seawater far better than stainless steel. It is not suitable for strong reducing acids such as hydrofluoric acid, or hot concentrated hydrochloric/sulphuric acid without inhibitors.
Q5. Is titanium lighter than stainless steel?
Yes. Titanium Grade 1 has a density of about 4.51 g/cm³, roughly 56% of carbon or stainless steel (about 7.9–8.0 g/cm³). Combined with its corrosion resistance, this low weight makes titanium flanges attractive for marine, offshore and aerospace applications where weight saving and chloride resistance both matter.
Q6. Can Titanium Grade 1 flanges be welded?
Yes. Titanium Grade 1 is readily welded by GTAW (TIG) and plasma processes using matching ERTi-1 / commercially pure titanium filler. The critical requirement is shielding: titanium must be fully protected from air (oxygen, nitrogen, hydrogen) at temperatures above ~260 °C using inert argon/helium shielding, trailing shields and back-purging, because contamination causes embrittlement. A clean, bright weld is essential; a straw, blue or grey/white weld indicates contamination and must be rejected.
Q7. What is the maximum service temperature of Titanium Grade 1 flanges?
Commercially pure Grade 1 titanium is generally used up to about 300 °C in continuous service; above this its strength falls and oxidation/oxygen pick-up increase. For higher-temperature or higher-strength duty, alpha-beta alloys such as Grade 5 (Ti-6Al-4V) are specified. Titanium also retains good toughness at low temperatures.
Q8. What are the equivalent grades of Titanium Grade 1?
Titanium Grade 1 (CP titanium) equivalents include UNS R50250, ASTM B381 F-1 / B348 Gr 1 / B265 Gr 1, DIN 3.7025 / Werkstoff 3.7025, and JIS Class 1 (Type 1). All denote the lowest-strength, highest-ductility commercially pure titanium.
Q9. What industries use Titanium Grade 1 flanges?
Titanium Grade 1 flanges are used in chlor-alkali plants (wet chlorine, chlorate, hypochlorite), desalination and seawater piping, marine and offshore systems, chemical processing (oxidising and organic acids), pulp & paper bleaching, power-plant seawater condensers, and electroplating/anode applications where the grade's high ductility and corrosion resistance are required.
Q10. Are Titanium Grade 1 flanges supplied with material test certificates?
Yes. Every Titanium Grade 1 flange is supplied with EN 10204 3.1 (or 3.2) mill test certificates confirming chemistry, mechanical properties and heat/lot traceability, with PMI, hydrostatic testing and third-party inspection on request. Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer and exporter from Mumbai, India.