ASTM A6, the general requirements standard for rolled structural steel, includes a section on supplementary requirements labeled S1 through S14. These requirements — covering everything from Charpy impact testing (S5) to vacuum treatment (S7) to ultrasonic testing (S8) — are explicitly optional. The standard states they apply only when specified in the order.
That optionality is the source of confusion for distributors. Material can be fully ASTM A6-compliant without any supplementary testing. But if a customer's PO says "S5 required," the material is not compliant for that customer without S5 Charpy test documentation on the MTC. The supplement is optional in the standard and mandatory in the transaction.
Most distributors hold inventory without tracking which heats have supplementary testing documented. The consequence: when a customer order requires S5, the inside sales rep doesn't know whether their stock qualifies. They either quote blindly and discover the problem at shipment, or they spend time manually pulling certs to check before quoting.
How Supplementary Requirements Work in Practice
When a mill receives a purchase order that invokes S5, they perform Charpy impact testing on the heat and document the results on the MTC. The cert will show the test temperature, the energy values (in ft-lbs or Joules), the number of specimens, and the individual results. If the order didn't invoke S5, the MTC won't have that section at all — not because the steel failed, but because the test wasn't required.
This creates a meaningful distinction between two plates of the same grade. Both might be SA-516 Grade 70. Both meet all required chemical and mechanical properties. One has S5 Charpy data at -50°F on the cert. The other doesn't. For a customer whose PO requires S5, only the first plate is usable — not because the second plate would have failed the test, but because the test wasn't performed and documented.
Distributors who stock material from multiple mills and multiple orders will have a mix of certs — some with supplementary testing, some without — even within the same grade and size.
The Problem With Not Tracking Supplementary Requirements
Quoting the wrong material. An inside sales rep receives an inquiry for SA-516-70 with S5 Charpy at -50°F. They quote from the available SA-516-70 inventory without checking whether the heats in stock have S5 documentation. The customer places the order. At shipment, someone pulls the cert. No S5 section. The material has to be sourced elsewhere, the order date slips, and the customer has a legitimate complaint.
Losing high-value orders. Customers requiring supplementary testing are often in regulated industries — pressure vessel fabrication, offshore construction, chemical processing. These are higher-value orders with repeat potential. If your quoting process can't confirm supplementary requirement coverage, you either quote everything as "pending cert review" (which slows response time and signals uncertainty) or you decline orders you might actually be able to fill.
Post-delivery rejections. The worst version: material ships, customer starts fabrication, quality check reveals no S5 on the cert. Material is rejected after work has begun. The distributor faces return freight, potential re-processing costs, and a quality nonconformance against their supplier record.
What Changes When You Track Supplementary Requirements in Inventory
When MTC data is structured and queryable — including supplementary requirement fields — the inside sales workflow changes.
At receiving, the cert intake process captures which supplementary requirements are documented on each MTC. For each heat received, the record notes: S5 at -50°F with specific energy values, S7 vacuum treatment, S8 ultrasonic testing to a specific level, or none. This becomes part of the heat's cert record.
When a customer order specifies supplementary requirements, the sales team can query inventory for qualifying heats in real time. The query returns heats where the documented supplementary testing matches what the customer requires.
The operational result: the inside sales team can give definitive answers on supplementary-requirement orders without cert chasing. They quote accurately, confirm availability with cert data, and avoid post-sale mismatches.
Building the Tracking Process
The entry point is cert intake. When an MTC is logged at receiving, the operator captures the supplementary requirement fields — what was tested, at what parameters, with what results. This requires a structured intake form rather than simply filing the PDF.
The secondary step is flagging orders. When a customer PO specifies supplementary requirements, that flag is captured on the order and matched against the cert record for the material being allocated.
For a distributor managing hundreds of heats across multiple grades and sizes, this process adds roughly 2 to 3 minutes per receipt for cert data entry. The return is the ability to serve supplementary-requirement orders with confidence — and the ability to stop losing those orders because your team couldn't confirm coverage before quoting.
Supplementary requirements are optional in the standard. In your customer's PO, they're a hard requirement. The only question is whether you know which of your heats covers them.