Tesco Steel & Engineering is a trusted global supplier, exporting ASME B16.5 Class 300 spectacle blind flanges to countries such as the USA, Germany, France, Italy, Saudi Arabia, UAE, and Kuwait. Our Figure 8 Blanks #300 are relied upon by customers across key industries like oil & gas, offshore platforms, petrochemicals, power generation, and water treatment. With a commitment to world-class manufacturing and customer satisfaction, we continue to support projects that demand durable, high-performance flange solutions built to international standards.
Manufactured at our high-tech Mumbai factory, every flange benefits from precision CNC machinery, laser cutting systems, and advanced in-house testing for performance and dimensional accuracy. Tesco Steel & Engineering is known for its superior quality manufacturing, ensuring that our Class 300 spectacle blind flanges are not only corrosion-resistant but also capable of withstanding demanding operating conditions. We offer these flanges in carbon steel, stainless steel, and various alloy grades to suit the needs of global customers across different sectors.
ASME B16.5 Class 300 Spectacle Blind Flanges, also referred to as Figure 8 Blanks #300, are specially designed for isolating sections of piping during inspection, repair, or shutdown. These flanges feature a unique dual-plate design—one solid and one ring—connected by a small bridge, allowing operators to alternate between open and closed positions without removing the unit. Ideal for medium-pressure systems, Tesco Steel & Engineering's spectacle blind flanges offer both operational safety and long-term reliability across a variety of industrial applications.
| NPS | Outside Ø A |
Inside Ø B |
Centerline C |
Thickness t |
Web Width W |
| 1/2 | 51 | 16 | 65 | 6.4 | 38 |
| 3/4 | 64 | 21 | 80 | 6.4 | 38 |
| 1 | 70 | 27 | 90 | 6.4 | 38 |
| 1¼ | 79 | 42 | 100 | 6.4 | 38 |
| 1½ | 92 | 48 | 115 | 6.4 | 38 |
| 2 | 108 | 61 | 125 | 9.7 | 51 |
| 2½ | 127 | 73 | 150 | 9.7 | 51 |
| 3 | 146 | 89 | 170 | 9.7 | 64 |
| 3½ | 162 | 102 | 185 | 12.7 | 64 |
| 4 | 178 | 114 | 200 | 12.7 | 64 |
| 5 | 213 | 141 | 235 | 15.7 | 76 |
| 6 | 248 | 168 | 270 | 15.7 | 76 |
| 8 | 305 | 219 | 330 | 22.4 | 76 |
| 10 | 359 | 273 | 385 | 25.4 | 102 |
| 12 | 419 | 324 | 450 | 28.4 | 102 |
| 14 | 483 | 356 | 515 | 31.8 | 108 |
| 16 | 536 | 406 | 570 | 38.1 | 108 |
| 18 | 594 | 457 | 630 | 41.1 | 114 |
| 20 | 651 | 508 | 685 | 44.5 | 121 |
| 24 | 772 | 610 | 810 | 50.8 | 140 |