Alloy 20 (Carpenter 20) Flanges
Teshi Group manufactures Alloy 20 (Carpenter 20) flanges (ASTM B462 UNS N08020, 2.4660) as an OEM in India — forged, machined, marked and certified in-house to ASME B16.5, ASME B16.47, EN 1092-1 and customer drawings.
When stainless and duplex steels are not enough, nickel–molybdenum and nickel–copper alloys handle wet chlorine, hydrochloric and hydrofluoric acids, ferric chlorides and hot sulphuric acid.
Alloy 20 (Carpenter 20) flanges at a glance
| Material | Alloy 20 (Carpenter 20) |
|---|---|
| Specification | ASTM B462 N08020 |
| UNS / W.Nr. | N08020 / 2.4660 |
| Sizes | NPS ½"–24" (ASME B16.5), 26"–60" (ASME B16.47 A / B), DN 10–600 (EN 1092-1) |
| Pressure class | Class 150, 300, 600, 900, 1500, 2500 · PN 6–40 |
| Facing / ends | RF, FF, RTJ, tongue & groove, male-female; serrated or smooth finish |
| Certification | EN 10204 3.1 standard · 3.2 with third-party inspection · IBR on request |
| Testing | PMI, hardness, dimensional; UT, IGC, impact and ferrite as specified |
Alloy 20 (Carpenter 20) chemistry and mechanical properties
Chemical composition of Alloy 20 (Carpenter 20) (weight %, maximum unless a range)
| Grade | C | Cr | Ni | Mo | Cu | Nb |
|---|---|---|---|---|---|---|
| Alloy 20 | 0.07 | 19.0–21.0 | 32.0–38.0 | 2.0–3.0 | 3.0–4.0 | 8×C – 1.00 |
Mechanical properties of Alloy 20 (Carpenter 20) (minimum, room temperature)
| Grade | Tensile strength | Yield strength (0.2 %) | Elongation | Note |
|---|---|---|---|---|
| Alloy 20 | 551 MPa (80 ksi) | 241 MPa (35 ksi) | 30 % | Hot H₂SO₄ |
Matching specifications by product form
| Grade | Forged flanges & fittings | Butt weld fittings | Plate | Pipe |
|---|---|---|---|---|
| Alloy 20UNS N08020 · W.Nr. 2.4660 | ASTM B462 N08020 | ASTM B366 WP20CB | ASTM B463 | ASTM B464 / B729 |
Limits and minimums from the governing ASTM / ASME specifications, summarised for convenience; the current edition takes precedence.
Pressure rating
Pressure–temperature ratings follow the ASME B16.5 / B16.47 material group for the grade. The applicable rating table is issued with every quotation, and flanges are marked with class, material and heat number.
Types we manufacture
Dimension charts
Where Alloy 20 (Carpenter 20) is used
- Wet chlorine and chlorine dioxide service (C-276, C-22)
- Flue-gas desulphurisation and pollution control
- Hydrofluoric acid alkylation and seawater (Monel 400)
- Hot sulphuric acid piping (Alloy 20)
- Pharmaceutical and fine-chemical reactors
Testing & certification
- PMI on every piece
- ASTM G28 intergranular corrosion testing when specified
- Solution annealing per specification
- EN 10204 3.1 certificate; 3.2 on request
Related materials
FAQ
Alloy 20 (Carpenter 20) flanges: common questions
What specification covers Alloy 20 (Carpenter 20) flanges?
Alloy 20 (Carpenter 20) flanges are forged to ASTM B462 N08020 and dimensioned to ASME B16.5, ASME B16.47 or EN 1092-1.
What is the chemical composition of Alloy 20?
Alloy 20 (UNS N08020): C 0.07, Cr 19.0–21.0, Ni 32.0–38.0, Mo 2.0–3.0, Cu 3.0–4.0, Nb 8×C – 1.00 (weight %; single values are maximums).
What are the minimum mechanical properties of Alloy 20?
Tensile strength 551 MPa (80 ksi), yield strength 241 MPa (35 ksi), elongation 30 %.
Is Teshi Group a manufacturer of Alloy 20 (Carpenter 20) flanges in India?
Yes. Teshi Group has manufactured flanges and fittings in India since 1971 and is ISO 9001:2015 certified and IBR approved. Every Alloy 20 (Carpenter 20) piece is hard-stamped with its heat number and supplied with an EN 10204 3.1 certificate; 3.2 with third-party inspection on request.
What is Hastelloy C-276 used for?
C-276 (UNS N10276) resists a very wide range of media including wet chlorine, ferric and cupric chlorides, and oxidising and reducing acids, so it is used in chemical reactors, FGD scrubbers and pollution-control systems.
Which specification covers Monel 400 flanges?
Monel 400 (UNS N04400) forged flanges are made to ASTM B564 and butt weld fittings to ASTM B366 WPNC.
Ready to build to spec?
Share your drawing, bill of materials or technical requirements with the Teshi team.