| Table | Class AKA lbs |
| I-1; Cast Iron Pipe Flanges & Fittings | 25 |
| I-2; Cast Iron Pipe Flanges & Fittings | 125 |
| I-3; Cast Iron Pipe Flanges & Fittings | 250 |
| I-4; Cast Iron Pipe Flanges & Fittings | 150 |
| I-5; Cast Iron Pipe Flanges & Fittings | 300, 400, 600, 900 |
| I-6; Cast Copper Alloy Pipe Flanges & Fittings | 150, 300 |
| I-7; Series A; Large Diameter Steel Flanges | 150, 300, 400, 600 |
| I-8; Series B; Large Diameter Steel Flanges | 75, 150, 300, 400, 600 |
| I-9; Corrosion-Resistant Cast Flanges & Fittings | 150LW |