ASTM A333 Gr 6 Blind FlangeASTM A350 · ASME B16.5 · Manufacturer, stockist & exporter, India
SA-333 Gr 6 · Low-temperature carbon steel pipe · BLRF
An ASTM A333 Gr 6 blind flange is a solid disc that closes the end of a pipe, valve or vessel nozzle, for use with ASTM A333 Gr 6 pipe. ASTM A333 Gr 6 itself is a pipe or plate specification, so the matching blind flange is made to ASTM A350 LF2 — which is what we supply for A333 Gr 6 lines. Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class.
- ASTM A350
- ASME B16.5
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an ASTM A333 Gr 6 Blind Flange?
- What it is
- A solid disc that closes the end of a pipe, valve or vessel nozzle
- Material
- ASTM A350 LF2
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Grade
- ASTM A333 Gr 6
- Best at
- Cold-climate and refrigerated piping down to −45 °C
ASTM A333 Gr 6 Blind Flange Specification
| Product | ASTM A333 Gr 6 Blind Flange |
|---|---|
| Material standard | ASTM A350 LF2 |
| Dimensional standard | ASME B16.5 · B16.47 · EN 1092-1 |
| Sizes | ½" – 24" (ASME B16.5) · 26" – 60" (ASME B16.47) |
| Pressure class | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | Chemical & mechanical per heat · NDT · impact where specified |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Blind Flange
Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class.
- No bore; thickness set by the pressure class
- Can be drilled and tapped for an instrument connection
- Often cut from plate in large sizes or special alloys
More on choosing: Blind flange guide.
ASTM A333 Gr 6 Blind Flange: Why A333 Gr 6 for blind flanges
Use a blind flange to terminate a line, close a nozzle for future connection, or allow pressure testing. It takes the full line pressure plus bolting load, so it is often the heaviest flange in a class. In ASTM A333 Gr 6, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Carbon and low-alloy flanges carry most utility, hydrocarbon and high-temperature service. ASTM A333 Gr 6 is picked for cold-climate and refrigerated piping down to −45 °C. |
|---|---|
| Typical service | LNG & refrigeration — Cold process lines. |
| B16.5 material group | 1.1 — A350 LF2 flanges are impact-tested for low-temperature service. |
| Bolting | ASTM A320 L7 studs with A194 Gr 7L nuts |
| Welding to carbon steel | Matching carbon or low-alloy filler is used; joints to stainless need ER309L |
| Matching filler | E7018-1 / ER80S-Ni1 |
ASTM A333 Gr 6 Blind Flange 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 Blind Flange 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 |
Full chemistry, properties and equivalents are on the ASTM A333 Gr 6 grade page.
Other ASTM A333 Gr 6 flanges
ASTM A333 Gr 6 Blind Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A333 Gr 6 Blind Flange dimensions — ASME B16.5 Class 150 & 300
Outside diameter, thickness and bolting are set by 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.
ASTM A333 Gr 6 Blind Flange — questions buyers ask
Can a blind flange be cut from plate?
For many sizes and classes, yes — especially in nickel alloys where forgings are expensive. The material then follows the plate standard and must be approved by the purchaser.
What pressure rating does a ASTM A333 Gr 6 blind flange have?
It depends on class and temperature. ASTM A333 Gr 6 forgings are in ASME B16.5 material group 1.1; read your class column in that group's table at the design temperature.
Can ASTM A333 Gr 6 blind flanges be welded to carbon steel?
Yes — matching carbon or low-alloy filler is used; joints to stainless need ER309L.
Which standard covers ASTM A333 Gr 6 blind flanges?
The material is ASTM A350 LF2; dimensions follow ASME B16.5 · B16.47 · EN 1092-1. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a ASTM A333 Gr 6 blind flange?
The steel price, the size and pressure class, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026