Ordering Bolts to A572 Grade 50

ASTM A572 is a common structural steel standard that covers five grades (42, 50, 55, 60, 65) of high strength, low-alloy structural steel shapes, plates, and bars that is intended for riveted, bolted, or welded construction. Fasteners are not specifically included in the scope of A572, but that doesn’t stop engineers and contractors from asking for A572 bolts.

Why is that an issue?

The inherent problem with trying to order bolts to a ASTM steel standard, is that steel standards like A572 do not include the necessary fastener information like bolt configuration, type of or amount of threads, style of head, compatible nut or washer, acceptable coatings, etc.  For example, ASTM A307, which covers low carbon general purpose bolts and studs, has the following sections detailing bolt specifics:

• Section 1.3, suitable nuts
• Section 7.1, thread geometry
• Section 7.2, head dimensions, thread length, other bolt dimensions
• Section 7.3, nut over-tapping allowances for hot dip galvanized bolts
• Section 9, test methods
• Section 13, product marking

Without these details, every mundane aspect of the fastener would need to be discussed and decided between the purchaser and the manufacturer, or assumptions would need to be made that may or may not meet the needs of the application the bolts are being used in.

ASTM A36 addresses this by including an appurtenant materials chart, guiding the reader to which fastener specific standards may be more appropriate.  A572 however, does not, so we are left without any clear fastener equivalents or recommendations.  Depending on your application and needs, we are happy to discuss what fastener options are available to you, although we cannot make recommendations.  That said, we do have several grades of A572 material available to us, so we are able to manufacture many varieties of fastener from that material.  We would simply need to discuss the specifics of the fastener configuration, using industry standards as our guide.  We will also provide a shop drawing with our quote, so that you can see exactly what you are getting before we begin.

Portland Bolt is happy to answer questions like these or similar.  We are the bolt experts; feel free to use us as a resource.