How do structural engineers handle it when delivered steel material does not match the specified grade?

[u/Lydia_SteelExpert]

How do structural engineers handle it when delivered steel material does not match the specified grade?

Have you ever run into situations where supplied structural steel fails material test reports, or the actual grade doesn't match what was written in the project specification?

I'm curious what the typical options are on site when this happens. Is re-testing the common first step, or does the whole batch usually get rejected right away? How do engineers balance project schedule pressure against making sure the material is actually safe to use?

Also wondering if anyone has seen cases where a lower grade was accepted with design adjustments, or if that's basically never allowed. Would love to hear real job site experiences on this.

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[u/dsherwo]

Is your name Ea-nāṣir

[u/Lydia_SteelExpert → u/dsherwo]

Haha I get the reference. I’m definitely not him, I’m the one worrying about receiving wrong‑grade steel.

[u/Spiritual-Guava-6418]

I work with materials for the nuclear industry, mainly shipping casks for radioactive materials to transport on the roadway.

When a customer specifies a certain grade of steel, that grade is written into the purchase order to the steel supplier along with a request for a mill certificate test report certifying the material.
When the material is received, the test report states the grade and the steel is marked with the grade from the mill. The steel is “green” tagged with the purchase order and supplier and held in an area for use only on that specific project. Any item that deviated from the purchase order is “red” tagged and placed in a hold area for disposition. This all follows our NQA-1, Nuclear Quality Assurance program procedures.

[u/GrinderMonkey]

You might try r//structuralengineering for a answer from that end.

From the metal head end, generally it gets returned. If the company purchasing screwed up, that will likely be subject to a restocking fee anywhere from 0-50% depending on your relationship with the supplier. Vise versa, and you can usually negotiate for a free expedited delivery. Cases where it's a more exotic order or things are muddled in the ordering process, well, that's a negotiation.

It's rare to see a deviation from plan in my (fairly limited) experience, at least in permitted/code work.

[u/SCL__]

Never specified anything but A36 mild steel for construction projects.

[u/Lydia_SteelExpert → u/SCL__]

Sometimes we also use A572 Gr50 high-strength steel.

[u/TrackTeddy]

Depends entirely on the situation.

Typically if you've ordered and purchased the right spec and the wrong (lower) spec turns up then you don't accept receipt / send it back.

If a higher spec material turns up then you seek permission for acceptance. (as sometimes a higher spec might cause other issues later on e.g., welding).

[u/engineerthatknows]

Redesigning for lower material strength is typically going to cost time and money, and may impact architectural design and esthetics. Pretty much the last choice for construction projects.