Newest FAQs

Washers for Structural Bolts

Are washers required to be used with an A325 or A490 structural bolt?

It is known that the required grade of washer to be used with an A325 or A490 structural bolt is an ASTM F436 hardened washer, however whether or not a washer is required to be used in a given application is often brought into question. The purpose of using a flat washer with a bolt... Read more

Custom F436 Washers

My plans are calling for a 1" thick, 5" outside diameter ASTM F436 plate washer. My local supplier is telling me that F436 washers only come in standard sizes that are much smaller. Are these larger F436 plate washers available?

Yes. Custom F436 washers can be manufactured to larger sizes per your job’s requirements. Portland Bolt has been involved in many projects where custom F436 washers were specifically called for on a job.  However, ASTM F436 does not technically allow for custom sizes and only allows for very specific types and styles that conform to... Read more

F1554 Grade 55 vs A307 Grade C

My plans call for an A307 grade C anchor bolt and my supplier is offering F1554 grade 55 anchor bolts as a substitution. Is this acceptable?

Theoretically, this substitution makes sense. However, one should always check with the project engineer before making any alterations to the grade or configuration of product that has been specified for the structure. Please note that for liability reasons, Portland Bolt is not recommending that this substitution be made without appropriate approval. The A307 grade A... Read more

Fully Threaded ASTM A325 Bolts

Can Portland Bolt manufacture a 1" x 6" fully threaded A325 heavy hex structural bolt?

Bolts manufactured to the ASTM A325 specification have a fixed thread length for a given diameter, which is often shorter than other grades of bolts. For example, a 3/4″ diameter A325 has 1-3/8″ of thread and a 1″ A325 has 1-3/4″ of thread, regardless of the overall length of the bolt. Our structural bolts product... Read more

Structural Bolt Connection Types

My company is looking to purchase A325SC, A325N, and A325X heavy hex structural bolts. What is the difference between these three?

There is no difference between these bolts. The “X”, “SC”, and “N” simply identify the type of connection the bolts are used in. “X” and “N” are bearing type connections, where the bolts are being used in shear. “X” means these particular A325 heavy hex structural bolts will be used in a bearing type connection... Read more

A325T

What is an A325T bolt?

An A325T bolt is a fully threaded version of an A325 heavy hex structural bolt. The A325 specification is very specific when it addresses thread lengths. Standard A325 bolts have very short thread lengths due to their application as a bolt intended for use in structural steel connections since often it is undesirable for threads... Read more

Ordering A193 Class 2 Bolts

What is an "A193 Class 2" heavy hex bolt and how do I order them?

ASTM A193 is a specification for alloy and stainless steel fasteners for high temperature service, high pressure service, or both. Within the A193 specification there are multiple grades of bolts made from either alloy or stainless steel. The stainless steel grades, such as B8 and B8M, can be ordered as either Class 1 (carbide solution... Read more

Max Temperature for Zinc Fasteners

What is the maximum service temperature limitation for hot-dip galvanized fasteners?

The answer to this question can be found in the appendix of the ASTM A194 specification, which deals with nuts for high temperature or high pressure service. Specifically, section X2.1 – Coatings and Application Limits. In this section it states that coated fasteners should not be used at temperatures above one half of the coating’s... Read more

Rebar Threading Issues and Solutions

Is it possible to put threads on rebar?

The answer is yes, however, there are several issues to consider to avoid liability. For this discussion, we will assume a requirement for threaded rebar as follows: #8 x 48″ long A615 grade 60 rebar with 8″ thread one end. What is rebar? Rebar is short for “reinforcing bar” and often used in concrete foundations... Read more

Wrench Openings and Socket Sizing

How do I determine the proper wrench opening or socket size to tighten a specific size of bolt?

Socket sizes and wrench openings for tightening nuts and bolts are determined by the dimension across the flats of either the nut or bolt head. According to the Machinery’s Handbook, 26th edition, “Wrenches are marked with the ‘nominal size of wrench’ which is equal to the basic or maximum width across flats of the corresponding... Read more