Do headed F1554 anchor bolts have a standard hex head or a heavy hex head?
ASTM F1554 does not specify whether the headed configuration is to be a standard hex pattern or heavy hex. There are three primary configurations covered by the ASTM F1554 specification which include straight rods, bent anchor bolts, and forged headed anchor bolts. Whether or not a headed anchor has a standard hex head or a heavy hex head can differ depending on the application. Since the head is embedded in the concrete, the designer or engineer may want a larger bearing surface than what a standard hex head would provide. If the head dimension is unspecified in the plans or specifications, it is best to leave the option of head style up to the manufacturer. Portland Bolt stocks headed F1554 anchor bolts and headed blanks in standard hex configurations and this flexibility may result in shorter lead times and less expensive bolts.
Although the ASTM F1554 specification does not specify what the head pattern should be, some ASTM grades do have specific requirements when it comes to the head style. Below is a chart specifying some common ASTM grades and whether or not they have requirements on the hex pattern of the head. It is important to keep in mind that this chart only specifies requirements in regard to hex headed bolts. These ASTM grades may also allow for other configurations such as bent anchor bolts, straight rods, or bolts with other head styles.
|ASTM Specification||Specified Head Configuration|
|A307 Grade A||Standard hex head (unless otherwise specified)|
|A307 Grade B||Heavy hex head (unless otherwise specified)|
|A325||Heavy hex head (only)|
|A449||Standard hex head (unless otherwise specified)|
|A193||Heavy hex head (unless otherwise specified)|
|A320||Heavy hex head (unless otherwise specified)|
|A354||Standard hex head (unless otherwise specified)|
|A490||Heavy hex head (only)|
|SAE J429 Grade 2, 5, 8||Standard hex head (unless otherwise specified)|