Newest FAQs

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

Hex Coupling Nut

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

Bolt Insurance

What is Product Liability Insurance? Which companies should have it?

Truly an asset you may not always like paying for but one you surely cannot live without. All manufacturers, wholesalers, distributors, in fact all those involved in the “stream of commerce” should have adequate product liability insurance. Product liability insurance is an insurance policy that would provide protection against liabilities, within the policy limits, for... Read more

Galvanizing Bolts for Pressure Treated Wood

Are current ASTM galvanizing standards suitable for use with the new chemicals being used in pressure treated wood? Some people have told me I need to use double or triple dipped fasteners. Is this true?

Since the new chemicals (alkaline copper quat [ACQ], copper azole [CBA-A and CA-B], and sodium borates [SBX]) now being used in pressure treated wood have been shown to be up to two or three times more corrosive than the previously used chromate copper arsenate (CCA), the recommended galvanizing thickness for materials being used with the... Read more

UL Listings and ICC-ES Reports

Do your products have a UL Listing or ICC-ES report available?

No. The products manufactured by Portland Bolt do not fall under the umbrella of products that would require a UL listing or ICC-ES report. There are three main governing bodies that cover specifications for fasteners. ASTM (American Society for Testing and Materials) covers primarily bolts and fasteners for construction applications. SAE (Society of Automotive Engineers)... Read more

Cutting Bolts in the Field

Is it acceptable practice to alter a bolt’s length in the field if it is too long?

Altering a bolt’s length or configuration in the field is acceptable as long as it does not change the length originally specified by the designer or engineer. If a bolt is longer than what was originally needed, the bolt can be cut down in the field. How the bolt is cut is important to consider.... Read more

ASTM A325 vs. Grade 5 bolts

What is the difference between Grade 5 and A325 bolts?

While these two bolts are virtually identical in terms of chemical and physical strengths and properties, there are several differences between the two. The Grade 5 specification falls under the Society of Automotive Engineers (SAE) classification system, while A325 is an ASTM specification. ASTM A325 bolts are more commonly specified by engineers for use in... Read more

Stainless Steel Grades

What are the differences between 18-8, type 304, and type 316 stainless steels?

To answer this question, you first need to know some basic information about stainless steel. “Stainless Steel” is the general name for a large family of alloy steels that contain at least 10.5% chromium as part of their composition. At and above this level of chromium, a complex chrome-oxide surface layer forms that prevents further... Read more