Anchor Bolts
Anchor bolts are covered by the standard ASTM F1554 specification for anchor bolts used to secure structures to concrete foundations. The standard covers configurations such as 90-degree bent anchors, rods with threads on both ends, fully threaded rods, and anchor bolts with a forged head. Each configuration can be manufactured custom from ½” to 4” diameter, depending on the grade. Anchor bolts are commonly installed in environments exposed to the weather, making hot-dip galvanizing a preferred option for corrosion protection. The F1554 specification is designed to ensure that anchor bolts provide adequate strength and performance for securing structural elements in concrete foundations, with clear guidelines for materials, design, and fabrication. It defines three material grades for anchor bolts:
Grade 36 – Minimum yield strength of 36 ksi
Grade 55 – Minimum yield strength of 55 ksi
Grade 105 – Minimum yield strength of 105 ksi
Structural Bolts
A structural bolt, as defined by the ASTM F3125 specification, is a high-strength fastener designed for use in structural applications, typically for steel connections. The specification covers various grades of bolts, such as A325 and A490, which are designed to have a heavy hex head. An alternate style of structural bolts is also available, known as TC bolts or Tension Control Bolts. Both styles are made of carbon or alloy steel and heat-treated for strength. These bolts are used with matching nuts and washers to secure steel members in construction. The F3125 standard outlines requirements for dimensions, mechanical properties, testing, and marking to ensure the bolts meet the necessary performance standards for safety and reliability in structural assemblies.
Hex and heavy hex nuts
Hex and heavy hex nuts are used with plate washers to create secure connections in structural applications. They distribute the load of the bolt over a larger area, preventing damage and minimizing stress concentrations. When tightened against plate washers, these nuts provide a firm grip, ensuring the fastener remains secure under dynamic loads. Plate washers also help maintain bolt alignment during installation, enhancing stability. Made from corrosion-resistant materials, hex, and heavy hex nuts improve durability in harsh environments. Their combination with plate washers streamlines the installation process, making them essential components in construction and manufacturing applications.
Common Hex and Heavy Hex nut Specifications: A563, A194, J429