Can all three grades of F1554 anchor bolts be galvanized?
The answer to this question is yes! All three grades within the ASTM F1554 specification, Grade 36, Grade 55, and Grade 105, can be either hot-dip galvanized or mechanically galvanized.The issues of hydrogen embrittlement and/or mechanical proterties being alerted during galvanizing are not an issue with any of these three grades. In Section 7 – Protective Coatings, the F1554 Specification states that hot-dip galvanizing must be done in accordance with ASTM Specification F2329,as well as stating that mechanical galvanizing must be done in accordance with Specification B695,Class55.
Can high strength bolts be hot-dip galvanized?
Some high strength bolts can be galvanized while others cannot. In the construction fastener industry, typically the phrase “high strength” refers to bolts that have been quenched and tempered (heat treated) to develop the proper strength requirements of a given specification. In many cases, low alloy steels like ASTM A572g50 or F1554g55 are called “high strength”. There are no issues galvanizing those low alloy grades.
Hydrogen Embrittlement Concerns
The first issue involves a phenomenon called hydrogen embrittlement which may occur when atomic hydrogen is absorbed by the steel during the acid pickling process that takes place prior to galvanizing. This embrittlement can potentially lead to the loss or partial loss of ductility in the steel and consequently result in the premature failure of the fastener in the field.
This information taken directly from the ASTM specifications supports our belief that hot-dip galvanizing of ASTM A354 grade BD and SAE J429 grade 8, whereas not specifically prohibited, should be avoided due to the risk of hydrogen embrittlement. Additionally, F3125/A490 bolts are specifically prohibited from being coated with any non approved metallic coating.
