Newest FAQs
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 F3125 grade A325 heavy hex structural bolt. The F3125 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... 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
Coupling Nut Grades
What grade of coupling nut should I use?A common question that we encounter has to do with what type of coupling nut should be used in conjunction with a particular grade of bolt or rod. Typically, a coupling nut would be specified as a grade of nut, as opposed to a grade of bolt. The ASTM grade of hex nut that is... Read more
Bolt Thread Pitch Series
What are my thread pitch options when ordering bolts?There are several different thread series available for construction fasteners. Below are the three of the most common thread series utilized in the fastener industry. Coarse Thread Series Unified National Coarse (UNC) – Coarse threads have fewer threads per axial distance than fine threads and a larger thread form relative to the diameter. Coarse thread... Read more
Non-Standard Thread on Structural Bolts
Is it possible to manufacture an A325 or A490 structural bolt with a non-standard thread length?Yes. At Portland Bolt we are frequently asked this question. In order to better understand the answer, some background information on these two specifications is necessary. Both the A325 and the A490 specifications cover high strength, heavy hex, structural bolts from ½” diameter through 1½” in diameter. Both ASTM A325 and A490 specify shorter thread... Read more