Newest FAQs

Stainless Yield & Tensile Strength

What are the strength and yield values for stainless steel bolts?

Typically when bolts are ordered, they are called out by a specific ASTM or SAE grade. Stainless steel bolts are a bit different though, as they are commercially available and regularly ordered simply by the material itself, most commonly 316 or 304 stainless steel. Unlike bolts that fall under ASTM specifications, there are no specific... Read more


What is the RCSC?

RCSC is the Research Council on Structural Connections. It is a non-profit, volunteer organization, comprised of over 85 leading experts in the fields of structural steel connection design, engineering, fabrication, erection and bolting. Its goal is to support research and gain knowledge to publish standards in structural steel connections.

Lock Washers with A325

Can I use a lock washer in an A325 structural connection?

Looking through both the ASTM specification F3125 Grade A325 and the Research Council on Structural Connections (RCSC) website, we have found neither mentioning the use of lock washers in a structural steel connection.  We interpret this as neither allowing nor forbidding the use and that it would ultimately be up to the engineer of record... Read more

Stainless Grade 55 All Thread

Can I get stainless steel all thread rod in grade 55?

The reference to “Grade 55” is for getting a stainless steel all thread rod with a minimum yield strength of 55,000 psi.  There are currently no stainless steel specifications commonly stocked that will guarantee a 55,000 psi yield strength. The most commonly stocked grades of stainless all thread rod are A193, A320, and F593. The... Read more

Bridge Washers

What is a bridge washer?

This is a term that is frequently used across the industry. More often than not, “bridge washers” will refer to cast iron malleable iron washers. These washers are typically used in dock and wood construction. Malleable iron washers are specifically designed to prevent bolt heads and nuts from pulling into the wood. Detailers will also... Read more

Galvanizing A193 Grade B7M

Can A193 Grade B7M bolts be hot-dip galvanized?

A193 Grade B7M is a grade variation of the common A193 Grade B7 used in high-temperature, high-pressure applications.  Nowhere in the A193 specification does it discuss whether or not A193B7M fasteners can be galvanized.  In theory, there is nothing preventing someone from galvanizing the material, however, the application in which these bolts are intended to... Read more


Does Portland Bolt sell hot-dip galvanized bolts that meet the A153 specification?

ASTM A153 is a broad specification covering zinc coating (hot-dip) of iron and steel hardware. In the past, A153 was the hot-dip galvanizing specification referenced by ASTM construction fasteners. The problem was that ASTM Committee F16 on Fasteners did not have any jurisdiction over this specification. Therefore, in 2005 the F2329 fastener-specific hot-dip galvanizing specification was established.... Read more


Does Portland Bolt sell zinc plated bolts that meet the B633 specification?

ASTM B633 is a broad specification covering electrodeposited zinc coating applied to iron or steel. In the past, this was the zinc plating specification referenced by ASTM construction fasteners. The problem was that ASTM Committee F16 on Fasteners did not have any jurisdiction over this specification. Therefore, in 1998 the F1941 fastener-specific zinc plating specification was... Read more

Coupling Nut Tapping

Are Portland Bolt’s stock coupling nuts tapped from one end or from each end?

Portland Bolt’s stock ungraded coupling nuts are tapped all the way through from one end, while our high strength and custom manufactured coupling nuts are tapped from both ends. What does this mean for your project? Coupling nuts are typically intended to connect two separate threaded fasteners together, although some applications require the coupling nut... Read more

3/8″ Diameter F1554 Grade 36

Are 3/8” diameter F1554 Grade 36 anchor bolts available?

No they are not, although this is a somewhat recent change. In the 2015 version of the ASTM F1554 specification, the smallest diameter allowed was changed from ¼” to ½”. This means that prior to 2015, 3/8” diameter F1554 anchor bolts were allowable, but since then it is no longer an option. The F16 committee of... Read more