What are the liability issues involved in substituting one fastener grade or configuration for another?

can-of-wormsHave you ever had a fastener company try to talk you into substituting A193 grade B7 all thread rod for F1554 grade 55 anchor rods, claiming it’s “better”? Have you allowed them to substitute an all thread rod with a nut tack welded in lieu of a headed bolt? These are scenarios that come up quite often in the fastener world. If you have allowed any type of grade or product substitution without an engineer’s approval, you may have opened a can of worms and exposed your company to a tremendous amount of liability. Worried? You probably should be.

Why do fastener salespeople try to substitute products?

Before we explore why these and other types of substitutions are often unacceptable, let’s take a step back and figure out why salespeople are so anxious to substitute one product for another. Whether you’re selling bolts, shoes, or cars, any Sales 101 course teaches that if you don’t have exactly what the customer is looking for, substitute something else before that customer has a chance to buy what they really want from your competitor. Trying to sell a customer a pair of Nike running shoes instead of the Adidas they preferred because you were out of stock in their size has no potential liability issue attached. Salespeople, especially commissioned ones, simply want to close the sale regardless of whether or not you end up with what you need. However, shoes don’t hold up bridges, support high-rise buildings, or secure light poles to their foundations. Allowing a salesman to substitute a different grade or configuration of fastener that an engineer has specified, could have catastrophic implications.

Most fastener companies do not employ engineers

Most fastener companies, whether they are a manufacturer like Portland Bolt or a distributor who simply buys and resells standard fasteners, do not employ structural engineers who are qualified to recommend substituting anything other than the exact grade and configuration of product that was originally specified. Engineers identify a specific grade of fastener for a connection based on a variety of factors that include strength, ductility, configuration, thread pitch, corrosion resistance, etc.

Limited or no manufacturing capabilities

To further understand why bolt salespeople attempt to sell you a different grade or configuration of product than you actually need requires a deeper understanding of the types of companies that comprise the fastener industry. Let’s start with bolt manufacturers. Portland Bolt is a manufacturer of nonstandard anchor bolts and construction fasteners. Our manufacturing capabilities are extremely broad and encompass headed bolts through 2-1/2″ diameter, bent bolts through 4-1/2″ diameter, and threaded rods through 6″ diameter. We inventory over one million pounds of round bar that will allow us to manufacture to virtually any ASTM bolt specification. On the other end of the spectrum are fastener distributors. These companies buy and resell mass-produced and imported fasteners in addition to wrenches, ladders, tools, hard hats, and other construction-related equipment. They have no manufacturing capabilities whatsoever. Somewhere in the middle of manufacturers and distributors lie hybrid companies who are primarily distributors, but also have limited manufacturing capabilities. Perhaps they thread mild steel round bar but don’t have the ability to forge headed bolts or thread high strength round bar. If you don’t know the manufacturing capabilities of your primary fastener supplier you should ask.

With a better understanding of the industry, it is easy to see that companies who do not have access to specific grades of steel or who do not have the ability to manufacture specific types of fasteners will undoubtedly attempt to pass off a different grade or style of fastener that they claim is “equal or better” than the grade or type of fastener that has been specified on your project. In this economy, desperation to consummate a sale may result in a salesperson attempting to substitute just about anything. If you take their word as gospel, you could be exposing your company to a tremendous amount of liability. Do you really want to gamble that a person who has been selling fasteners for six months really knows if the bolt they are passing off as an acceptable substitute really is? Knowingly supplying incorrect product can have devastating legal implications.

Product liability insurance… what’s that?

Ever asked your primary bolt supplier how much product liability insurance they carry? What if they suggest a substitution that gets rejected…worse yet…..after installation? What now? Well, they will certainly step up and replace the product, pay for the cost of labor to remove and reinstall the correct fasteners that should have been supplied in the first place, and cover any back charges….won’t they? Don’t be so sure. Next time you talk with them you might find out if they carry enough insurance to fix their mistake. You might discover you’ll be on your own.

Common misconceptions

Let’s look at the two most common misconceptions in the fastener industry.

Misconception #1 – Stronger is always better

In the fastener industry, stronger is NOT always better. An engineer may have wanted a certain combination of strength and ductility that a particular fastener specification offers. Substituting a stronger fastener results in a reduction in ductility which could have disastrous results.

In the opening of this FAQ, we used an example of the common practice of substituting A193 grade B7 for F1554 grade 55 anchor rods (or just about any other ASTM specification for that matter). A193 Grade B7 all thread rod is a high strength material that will exceed the strength of many other ASTM specifications. The tantalizing thing about B7 rod is that virtually every fastener company in the country stocks it. It is a quick fix for just about any situation due to its relatively low cost and immediate availability. However, B7 doesn’t meet the requirements of F1554 grade 55 due to the fact that F1554 grade 55 has a maximum tensile strength requirement of 95ksi that A193 grade B7 will always exceed (125 ksi minimum). In essence, B7 is too strong to meet the requirements of F1554 grade 55. There is a good chance that the engineer specifying the fasteners wanted the combination of strength, ductility, and/or weldability that F1554 grade 55 provides.

Misconception #2 – Threaded rod with a nut tack welded can be substituted for headed bolts

First, only mild steel rods should be welded. AISC recommends against welding high strength materials. Applying heat during a welding operation could alter the mechanical properties of high strength steel. Second, Portland Bolt’s in-house testing of certain rods with nuts in lieu of forged heads found a significant reduction in strength.


If you are a purchasing agent, project manager, superintendent, or in any other role that empowers you to procure fasteners for your company, you have a tremendous responsibility to your organization to purchase the exact product that has been specified on your project. If you allow a fastener company to sell you an alternate product they claim will be an acceptable substitute, it is your responsibility to make sure that product will work for your application. If you don’t, you may be opening a can of worms.

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    Gentlemen, thank you for your continued efforts to lift the fog from manufacturing and construction eyes who, through no one’s fault, would otherwise be totally out to lunch on Headed bolts.
    I have an issue that you might be able to help with. I have a project with F1554 Gr36 anchor bolt (in concrete) requirement. What was supplied was A307 gr36 headed bolts. Is this ok or should i now ask for the mill test report and look for the (yield strength testing)?


    @John- I would look at the mill cert and see if the requirements of F1554g36 are met. If they are, then it is a non-issue. If they are not, you’ll need to decide if they are acceptable. It also sounds like someone is trying to dual-certify bolts by marking them both A307 and AB36. Theoretically there is nothing wrong with that, but per the F1554 standard, if they are marked, they are supposed to be marked on the end that projects from the concrete. If marking not required (it is a supplemental requirement), then the bolts should be painted blue on the projection end.

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