ASTM A333 Gr 6 FlangesASTM A350 LF2 · Manufacturer, stockist & exporter, India
Also sold as SA-333 Gr 6 · Low-temperature carbon steel pipe · LTCS
ASTM A333 Gr 6 flanges are forged to ASTM A350 LF2 and machined to ASME B16.5 (½"–24", Class 150–2500) or ASME B16.47 for larger sizes. It is a low-temperature carbon steel pipe, impact-tested to −45 °C, chosen for cold-climate and refrigerated piping down to −45 °C. 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 A333 Gr 6 Flanges?
ASTM A333 Gr 6 flanges is a low-temperature carbon steel pipe, impact-tested to −45 °C supplied as flanges to ASTM A350 LF2. Buyers specify it for cold-climate and refrigerated piping down to −45 °C. It is also sold as SA-333 Gr 6, Low-temperature carbon steel pipe, LTCS.
- What it is
- Low-temperature carbon steel pipe, impact-tested to −45 °C
- Material
- ASTM A350 LF2
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Classes
- 150 · 300 · 600 · 900 · 1500 · 2500
- Facing
- RF · FF · RTJ
- Best at
- Cold-climate and refrigerated piping down to −45 °C
ASTM A333 Gr 6 Flanges Specification & Sizes
| Material standard | ASTM A350 LF2 |
|---|---|
| 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 |
Standards on this page
ASTM A333 Gr 6 Flange Pressure–Temperature Rating
The class is not a pressure: the allowable pressure for A333 Gr 6 flanges comes from the ASME B16.5 table for its material group, and falls as temperature rises (how ratings work). ASTM A350 LF2 is in material group 1.1. A350 LF2 flanges are impact-tested for low-temperature service.
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 A333 Gr 6 Flanges
For ASTM A333 Gr 6 flanges the usual bolting is ASTM A320 L7 studs with A194 Gr 7L 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 A333 Gr 6 Flanges Chemical Composition
| Element | Weight % |
|---|---|
| Carbon | 0.30 max |
| Manganese | 0.29 – 1.06 |
| Silicon | 0.10 min |
| Phosphorus | 0.025 max |
| Sulphur | 0.025 max |
ASTM A333 Gr 6 Flanges Mechanical Properties
| Minimum values | Value |
|---|---|
| Tensile strength | 415 MPa · 60 ksi |
| Yield strength 0.2% | 240 MPa · 35 ksi |
| Elongation | 30% |
| Charpy impact | Tested at −45 °C |
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Melting range | 1420 – 1530 °C |
| Magnetic | Magnetic |
ASTM A333 Gr 6 Equivalent Grades
Values follow ASTM A333 Grade 6. Always check against the edition named on your purchase order.
ASTM A333 Gr 6 flange dimensions — ASME B16.5 Class 150 & 300
Outside dimensions depend only on size and class, not on the alloy, so A333 Gr 6 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 A333 Gr 6 Flanges Price — What Decides It
Two quotes for "A333 Gr 6 flanges" can differ by 20% and both be fair. We quote A333 Gr 6 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 A333 Gr 6 flanges by type
ASTM A333 Gr 6 Flanges Applications
ASTM A333 Gr 6 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 A333 Gr 6 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 and material is PMI-tested before processing.
- 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 A333 Gr 6 Flanges
ASTM A333 Gr 6 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | E7018-1 / ER80S-Ni1 |
|---|---|
| Over-alloyed filler | Impact-tested procedure required |
| 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 A333 Gr 6 fittings and A333 Gr 6 flanges for the matching pipe-system parts.
How to Order ASTM A333 Gr 6 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 A333 Gr 6 flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A333 Gr 6 flanges — questions buyers ask
Is ASTM A333 Gr 6 the same as SA-333 Gr 6?
Yes. SA-333 Gr 6, Low-temperature carbon steel pipe, LTCS all refer to the same material, and flanges is ordered to ASTM A350 LF2 whichever name is on the enquiry.
Which standard covers ASTM A333 Gr 6 flanges?
ASTM A350 LF2 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 A333 Gr 6 Class 300 flange take?
It depends on temperature. ASTM A350 LF2 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 A333 Gr 6 flanges?
Usually ASTM A320 L7 studs with A194 Gr 7L nuts. In corrosive or sour service the bolting material is set by the project specification.
Can a ASTM A333 Gr 6 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