Join standard-sized steel and cast iron pipe flanges—these kits come with the screws and nuts in the right size and number to match the bolt holes. The screw heads and nuts are 10% wider than standard hex fasteners, so they spread force over a larger area, and you can tighten with more torque.

The most common heavy hex head screw, these steel screws meet ASTM A325 regulations for structural joints, such as mating I-beams and scaffolding.

About half as strong as medium-strength steel screws, these screws are best for light duty fastening applications, such as securing access panels. The flange distributes pressure where the screw meets the surface, so you don’t need a separate washer.

These steel screws are hot-dipped galvanized to resist corrosion in wet environments.