Nuts supplied with galvanized anchor bolts will meet ASTM grades A563 or A194, while washers will conform to ASTM grade F436 or F844.

Nuts

A563: This is the most commonly used nut specification. Lower strength bolts will typically use Grade A nuts, while higher strength bolts will typically use Grade DH nuts. A563 grade Grade DH nuts are suitable replacements for lower grades per A563 table X.1. A194 Grade 2H nuts are a suitable replacement for A563 grade DH per A563 table 3 notes C and D. Galvanized nuts are tapped oversize per A563 table 5 to accommodate the galvanized coatings on the bolts. Galvanized A563 grade DH nuts are required to have a wax lubricant and dye coating per section 4.8.1 of the ASTM specification.

A194: This is a nut specification for high temperature or high-pressure service, or both. Grade 2H nuts are more readily available than A563 grade DH nuts and are a suitable replacement per A563 table 3 notes C and D.

Washers

F436: This is the ASTM specification for hardened steel washers. It is the preferred washer for the ASTM F1554 anchor bolt specification.

F844: This is the specification for unhardened washers. Unhardened washers have a larger outside diameter than F436 washers.

Nut and Washer Compatibility Chart

This chart provides compatible nuts and washers for various ASTM grades of anchor bolts. The nuts listed in this chart meet or exceed the minimum compatibility requirements and are based on products that are readily available in the marketplace. Many of the nuts “recommended” by ASTM for various grades of anchor bolts are not available in certain diameter ranges, finishes, or domestically manufactured. Portland Bolt’s website contains a more detailed Nut Compatibility Chart as recommended by ASTM, with the understanding that many of those nuts will simply not be available.