IBR SA105 Flanges
Teshi Group is an IBR approved OEM manufacturer of IBR SA105 flanges in India — weld neck, slip-on, socket weld, threaded, lap joint and blind flanges to ASME B16.5 (NPS ½″–24″, Class 150–2500) and B16.47 — for carbon steel feed water and steam lines up to about 425 °C.
Every lot is inspected by the Inspecting Authority and supplied with the IBR certificate of manufacture and test (Form III-C), EN 10204 3.1 mill certificates and full heat-number traceability.
IBR SA105 Flanges at a glance
| Supply | OEM manufacturer — Teshi Group, India |
|---|---|
| Material | ASTM A105 · ASME SA-105 |
| UNS | K03504 |
| EN equivalent | P250GH |
| Chinese GB equivalent | 20 / 16Mn (NB/T 47008) |
| Products | weld neck, slip-on, socket weld, threaded, lap joint and blind flanges to ASME B16.5 (NPS ½″–24″, Class 150–2500) and B16.47 |
| Typical IBR service | Carbon steel feed water and steam lines up to about 425 °C |
| Certificate | IBR Form III-C countersigned by the Inspecting Authority; EN 10204 3.1 |
Chemical composition and strength
| Grade | C% | Cr% | Mo% | YieldMPa min | TensileMPa min | Heat treatment |
|---|---|---|---|---|---|---|
| ASTM A105 | 0.35 max | 0.30 max | 0.12 max | 250 | 485 | Not mandatory for standard flanges up to Class 300; anneal, normalize, N&T or Q&T required above Class 300, for special designs and similar cases (A105N = normalized) |
Matching IBR components
| Component | Grade | IBR certificate |
|---|---|---|
| Pipe | ASTM A106 Grade C | Form III-A |
| Butt-weld fittings | ASTM A234 WPB | Form III-C |
| Flanges & forged fittings | ASTM A105 | Form III-C |
How Teshi Group makes and certifies IBR material
Order review
Confirm IBR applicability, design pressure and temperature, material grade, size, rating and the Inspecting Authority named in the order.
IBR-acceptable raw material
Forging bar, billets, plate or pipe bought with mill certificates acceptable under IBR (Well-known Steel Maker or Inspecting Authority-tested material), recorded by heat number.
Manufacture
Forging, heat treatment and machining to ASME B16.5, B16.47, B16.9 or B16.11, with the heat number transferred to every piece.
Inspection and testing
Chemical and mechanical tests, hardness, dimensional inspection and NDT as required, witnessed and verified by the Inspecting Authority.
Stamping and certificate
Each piece is hard-stamped and the IBR certificate of manufacture and test is signed by Teshi Group and countersigned by the Inspecting Authority.
Dispatch
Material ships with the IBR certificate, EN 10204 3.1 mill test certificates and the dimensional report, traceable piece by piece.
IBR certificates
| Certificate (IBR 1950 name) | What it certifies | Used for |
|---|---|---|
| Form III-A | Certificate of manufacture and test of steam pipes | IBR pipes |
| Form III-B | Certificate of manufacture and test of tubes, signed by the Inspecting Authority or a Well-known Tube Maker | Boiler tubes |
| Form III-C | Certificate of manufacture and test of boiler mountings and fittings — the certificate buyers ask for with IBR flanges, fittings and valves | IBR flanges and fittings |
| Form III-F | Certificate of manufacture and test of castings, by the Inspecting Authority or a Well-known Foundry | Cast valve bodies |
| Form III-G | Certificate of manufacture and test of forgings, by the Inspecting Authority or a Well-known Forge | Forgings |
| Form IV | Steel maker's certificate of manufacture and test (Well-known Steel Maker) | Raw material |
| Form IV-A | Certificate of material tested by the Inspecting Authority where the maker's certificate is not available | Raw material |
The Indian Boiler Regulations, 2026 consolidate these certificates under a renumbered set of forms. Until your boiler inspectorate confirms the form required on a specific job, buyers and inspectors still refer to the 1950 names — Form III-A for pipes and Form III-C for flanges and fittings — and Teshi Group issues the certificate in the form prescribed at the time of supply.
FAQ
IBR SA105 Flanges: common questions
Do you supply SA105 flanges with IBR certificates?
Yes. Teshi Group supplies IBR SA105 flanges with the IBR certificate (Form III-C) countersigned by the Inspecting Authority, plus EN 10204 3.1 mill test certificates.
What is the minimum yield strength of SA105?
250 MPa, with a minimum tensile strength of 485 MPa.
Where is SA105 used in IBR piping?
For carbon steel feed water and steam lines up to about 425 °C.
Which grades match SA105 in an IBR line?
ASTM A106 Grade C pipe, ASTM A234 WPB butt-weld fittings and ASTM A105 flanges.
What is the Chinese equivalent of SA105?
The nearest Chinese grade is 20 / 16Mn (NB/T 47008).
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