Inconel 718 Spectacle BlindASME B16.48 · Manufacturer, trader & exporter, India
Alloy 718 · UNS N07718 · SB
An Inconel 718 spectacle blind is a figure-8 plate with one solid end and one open ring, fitted between two flanges, made from Inconel 718 to project / purchase specification dependent. A spectacle blind lets operators positively isolate a line: rotate the solid end into the line to block flow, or the ring end to allow it. Larger sizes use separate spacers and paddle blanks.
- Inconel 718
- ASME B16.48
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Inconel 718 Spectacle Blind?
- What it is
- A figure-8 plate with one solid end and one open ring, fitted between two flanges
- Material
- project / purchase specification dependent
- Dimensions
- ASME B16.48
- Grade
- Inconel 718 · UNS N07718
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Spectacle Blind Specification
| Product | Inconel 718 Spectacle Blind |
|---|---|
| Material standard | project / purchase specification dependent |
| Dimensional standard | ASME B16.48 |
| 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 | PMI (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose a Spectacle Blind
A spectacle blind lets operators positively isolate a line: rotate the solid end into the line to block flow, or the ring end to allow it. Larger sizes use separate spacers and paddle blanks.
- Thickness set by class and size
- Paddle blank and spacer versions for large bores
- Handle or lifting lug to order
More on choosing: Spectacle blind guide.
Inconel 718 Spectacle Blind: Why 718 for spectacle blinds
A spectacle blind lets operators positively isolate a line: rotate the solid end into the line to block flow, or the ring end to allow it. Larger sizes use separate spacers and paddle blanks. In Inconel 718, 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 | Nickel-alloy flanges are used where acids, chlorides or heat defeat stainless. Inconel 718 is picked for very high strength at temperatures up to about 650 °C. |
|---|---|
| Typical service | Oil & gas — Wellhead parts, hangers and high-strength bolting. |
| Bolting | B7 (coated), B8M or nickel-alloy studs in Inconel 718 (bar to ASTM B637, where applicable), as the project specifies |
| Welding to carbon steel | A nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel |
| Matching filler | ERNiFeCr-2 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 718 Spectacle Blind Chemical Composition
| Element | Weight % (producer reference) |
|---|---|
| Nickel (+Co) | 50.00 – 55.00 |
| Chromium | 17.00 – 21.00 |
| Iron | Balance |
| Niobium (+Ta) | 4.75 – 5.50 |
| Molybdenum | 2.80 – 3.30 |
| Titanium | 0.65 – 1.15 |
| Aluminium | 0.20 – 0.80 |
| Cobalt | 1.00 max |
Inconel 718 Spectacle Blind Mechanical Properties
No specification requirement is asserted for this product form; requirements are to the purchase specification.
Full chemistry, properties and equivalents are on the Inconel 718 grade page.
Other Inconel 718 flanges
Inconel 718 Spectacle Blind — questions buyers ask
When should I use a spacer and paddle blank instead of a spectacle blind?
In large sizes a spectacle blind becomes too heavy and awkward, so ASME B16.48 provides separate paddle blanks and spacers.
Can Inconel 718 spectacle blinds be welded to carbon steel?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel.
Which standard covers Inconel 718 spectacle blinds?
The finished flange specification is project / purchase specification dependent, so none is named here; dimensions follow ASME B16.48. State the flange specification your project requires on the purchase order.
What decides the price of a Inconel 718 spectacle blind?
The alloy price, the size and pressure class, quantity, and the testing and documents required. Send your list and we quote the same working day.
Can you supply Inconel 718 spectacle blinds to NACE MR0175?
Yes. Inconel 718 is listed in NACE MR0175 / ISO 15156-3 within its limits; state NACE compliance on the order and it is confirmed on the certificate.
What documents do you supply?
EN 10204 3.1 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026