ASTM A106 Gr B FlangesASTM A105 · Manufacturer, stockist & exporter, India
Also sold as SA-106 Gr B · Seamless carbon steel pipe · UNS K03006
ASTM A106 Gr B flanges are forged to ASTM A105 and machined to ASME B16.5 (½"–24", Class 150–2500) or ASME B16.47 for larger sizes. It is a seamless carbon steel pipe for high-temperature service, chosen for high-temperature process and steam piping in refineries and power plants. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- Mill test certificates
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is ASTM A106 Gr B Flanges?
ASTM A106 Gr B flanges is a seamless carbon steel pipe for high-temperature service supplied as flanges to ASTM A105. Buyers specify it for high-temperature process and steam piping in refineries and power plants. It is also sold as SA-106 Gr B, Seamless carbon steel pipe, UNS K03006.
- What it is
- Seamless carbon steel pipe for high-temperature service
- Material
- ASTM A105
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Classes
- 150 · 300 · 600 · 900 · 1500 · 2500
- Facing
- RF · FF · RTJ
- Best at
- High-temperature process and steam piping in refineries and power plants
ASTM A106 Gr B Flanges Specification & Sizes
| Material standard | ASTM A105 |
|---|---|
| Dimensional standards | ASME B16.5 (½"–24") · B16.47 Series A / B (26"–60") · B16.36 orifice · B16.48 line blanks · EN 1092-1 |
| Pressure classes | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | Raised face (RF) · flat face (FF) · ring type joint (RTJ) · tongue & groove |
| Bore | To match the pipe schedule — specify it on the order |
| Types | Weld neck flange · Slip-on flange · Blind flange · Socket weld flange · Threaded flange · Lap joint flange · Long weld neck flange · Orifice flange · Spectacle blind · Reducing flange · Ring type joint flange · Expander flange · Anchor flange · Swivel ring flange |
| Testing | PMI · dimensional · UT of forgings · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
ASTM A106 Gr B Flange Pressure–Temperature Rating
The class is not a pressure: the allowable pressure for A106 B flanges comes from the ASME B16.5 table for its material group, and falls as temperature rises (how ratings work). ASTM A105 is in material group 1.1.
Take the actual pressures from the B16.5 rating table for group 1.1. A class is not a project pressure rating — your piping class sheet and design conditions govern.
Bolting & Gaskets for A106 B Flanges
For ASTM A106 Gr B flanges the usual bolting is ASTM A193 B7 studs with A194 2H nuts. Spiral-wound gaskets with carbon-steel outer rings are standard for raised-face carbon-steel flanges. Facing and gasket options are compared in the flange guide.
ASTM A106 Gr B Flanges Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Chromium | As specified |
| Copper | As specified |
| Nickel | As specified |
| Molybdenum | As specified |
| Vanadium | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A106 Grade B.
ASTM A106 Gr B Flanges Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A106 Grade B — condition per order.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Melting range | 1420 – 1530 °C |
| Magnetic | Magnetic |
ASTM A106 Gr B Equivalent Grades
ASTM A106 Gr B flange dimensions — ASME B16.5 Class 150 & 300
Outside dimensions depend only on size and class, not on the alloy, so A106 B flanges bolt to any B16.5 flange of the same size and class. Values in mm; thickness excludes the 1.6 mm raised face.
| NPS | Cl 150 OD | Cl 150 thickness | Cl 150 bolt circle | Cl 150 bolts | Cl 300 OD | Cl 300 thickness | Cl 300 bolt circle | Cl 300 bolts |
|---|---|---|---|---|---|---|---|---|
| ½" | 90 | 9.6 | 60.3 | 4 × ½" | 95 | 12.7 | 66.7 | 4 × ½" |
| 1" | 110 | 12.7 | 79.4 | 4 × ½" | 125 | 15.9 | 88.9 | 4 × ⅝" |
| 1½" | 125 | 15.9 | 98.4 | 4 × ½" | 155 | 19.1 | 114.3 | 4 × ¾" |
| 2" | 150 | 17.5 | 120.7 | 4 × ⅝" | 165 | 20.7 | 127.0 | 8 × ⅝" |
| 3" | 190 | 22.3 | 152.4 | 4 × ⅝" | 210 | 27.0 | 168.3 | 8 × ¾" |
| 4" | 230 | 22.3 | 190.5 | 8 × ⅝" | 255 | 30.2 | 200.0 | 8 × ¾" |
| 6" | 280 | 23.9 | 241.3 | 8 × ¾" | 320 | 35.0 | 269.9 | 12 × ¾" |
| 8" | 345 | 27.0 | 298.5 | 8 × ¾" | 380 | 39.7 | 330.2 | 12 × ⅞" |
| 10" | 405 | 28.6 | 362.0 | 12 × ⅞" | 445 | 46.1 | 387.4 | 16 × 1" |
| 12" | 485 | 30.2 | 431.8 | 12 × ⅞" | 520 | 49.3 | 450.8 | 16 × 1⅛" |
Full chart: ASME B16.5 flange dimensions.
Six-digit Harmonized System heading (iron and steel, chapter 72–73). Your country adds its own digits — confirm with your customs broker. All HS codes.
ASTM A106 Gr B Flanges Price — What Decides It
Two quotes for "A106 B flanges" can differ by 20% and both be fair. We quote A106 B flanges per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
ASTM A106 Gr B flanges by type
ASTM A106 Gr B Flanges Applications
ASTM A106 Gr B is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
How your A106 B flanges order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI before processing is available on request.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Standards on this page
Welding & Fabricating ASTM A106 Gr B Flanges
ASTM A106 Gr B welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ER70S-6 / E7018 |
|---|---|
| Over-alloyed filler | Preheat thick walls per the WPS |
| Preheat | As required by the WPS and code for the thickness |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also A106 B fittings and A106 B flanges for the matching pipe-system parts.
How to Order ASTM A106 Gr B Flanges: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Flange type and dimensional standard (B16.5 / B16.47 / EN 1092-1)
- Size, pressure class and facing
- Bore / schedule for weld neck and socket weld flanges
- Material standard and grade marking
- Certificate type and extra tests
- Delivery port, Incoterm and required date
ASTM A106 Gr B flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A106 Gr B flanges — questions buyers ask
Is ASTM A106 Gr B the same as SA-106 Gr B?
SA-106 Gr B, Seamless carbon steel pipe, UNS K03006 are names used for ASTM A106 Gr B, and flanges is ordered to ASTM A105 whichever name is on the enquiry.
Which standard covers ASTM A106 Gr B flanges?
ASTM A105 is the material specification for the forging; dimensions follow ASME B16.5 for ½"–24" and ASME B16.47 for 26" and above. European projects use EN 1092-1.
What pressure can a ASTM A106 Gr B Class 300 flange take?
It depends on temperature. ASTM A105 is in ASME B16.5 material group 1.1; read the Class 300 column of that group's table at your design temperature.
Which bolts should I use with ASTM A106 Gr B flanges?
Usually ASTM A193 B7 studs with A194 2H nuts. In corrosive or sour service the bolting material is set by the project specification.
Can a ASTM A106 Gr B flange be welded to a different pipe material?
Yes — matching carbon or low-alloy filler is used; joints to stainless need ER309L. Weld neck bores must match the mating pipe schedule.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026