Marine Hardware Quality Documentation: MTR, FAI, and What to Require
MTRs verify raw material composition. FAI reports confirm the first production part meets the drawing. COCs certify shipment conformance. PMI verifies the material the fabricator actually used. Requiring all four from every supplier is standard practice for OEM boat builders managing warranty exposure.
Why Quality Documentation Is Now a Business Requirement
Purchasing managers at boat builders are increasingly required to maintain quality documentation files for every production part — not because they want to, but because ABYC compliance programs, insurance requirements, and warranty defense situations have made documentation a business necessity rather than a best practice. Most marine hardware suppliers cannot provide the documentation that serious OEM programs now require. Understanding what each document type is, what it confirms, and how to make it a standard vendor requirement is the practical skill that separates purchasing teams that manage quality proactively from those that respond to failures reactively.
Marine Hardware Quality Document Types
Mill Test Reports (MTRs)
A mill test report (MTR) — also called a material test report or material certification — is a document produced by the metal mill that manufactured the raw material. It reports the chemical composition and mechanical properties of a specific heat (production batch) of metal, traceable by heat number to the material used to produce the part. An MTR for 316 stainless steel will show chromium, nickel, molybdenum, carbon, and other element percentages, confirming the material meets ASTM A276 or A240 composition requirements. For marine hardware programs, MTRs provide chain-of-custody documentation that the specified alloy was used.
MTRs have an important limitation: they document what the mill produced, not what the fabricator actually used. Material can be mislabeled, substituted, or mixed at the distributor level between the mill and the fabrication shop. An MTR showing 316 stainless does not guarantee that 316 stainless was actually used to make the part in hand. PMI testing — using XRF analysis to verify the composition of the actual fabricated part — closes this gap. MTR plus PMI provides both the chain-of-custody paper trail and the physical verification that the paper trail is accurate.
First Article Inspection (FAI) Reports
A first article inspection (FAI) report documents that the first production part made to a drawing meets all dimensional, material, and process requirements before the full production run begins. It is the primary tool for validating that a new supplier, a new production process, or a design change has been correctly implemented. A complete FAI report includes: dimensional measurements at every callout on the drawing, material confirmation (typically referencing MTR and/or PMI results), finish verification, and a formal pass/fail disposition signed by a qualified inspector. Requiring FAI before production release is standard practice for OEM programs and eliminates the risk of discovering a systematic production error after thousands of pieces have been made.
Certificates of Conformance (COCs)
A certificate of conformance (COC) is a document accompanying a production shipment that certifies the lot conforms to the specified requirements. COCs typically reference: the part number and revision, the purchase order, the quantity shipped, the applicable specification or drawing revision, and a statement that the material was produced and inspected per the applicable requirements. For marine hardware programs, COCs provide the shipment-level documentation record that the receiving team needs to clear incoming inspection without physically measuring every part. COCs do not replace first article validation — they certify ongoing production conformance after FAI has established that the process produces conforming parts.
Dimensional Inspection Records
Dimensional inspection records document actual measured values for critical dimensions on production parts, typically on a sampling basis. Unlike a COC (which is a declaration of conformance), dimensional inspection records provide actual data: what was measured, when, by whom, using what equipment. For dimensions that are critical to assembly fit — mounting hole patterns, mating surface flatness, thread engagement length — dimensional inspection records allow the purchasing team to trend data across shipments and identify process drift before it produces non-conforming parts. Suppliers who maintain dimensional inspection records and can provide them on request are operating a measurable quality system rather than relying on end-of-line visual inspection.
ASTM B117 Salt Spray Test Reports
For programs requiring validated finish performance, ASTM B117 salt spray test reports provide documented corrosion resistance data for finished parts. ASTM B117 exposes test panels or finished parts to a controlled salt fog environment and measures how long before corrosion initiates. This is particularly relevant for anodized aluminum marine hardware where anodize depth, seal quality, and base metal preparation all affect the result. PW Marine OEM can support B117 testing requirements for programs that need documented finish qualification before production release.
How to Make Documentation a Standard Vendor Requirement
Making quality documentation a vendor requirement starts at the purchase order level. The PO should specify: MTRs required on all raw material (heat-traceable to the parts ordered), FAI required before production release for new parts and after any drawing revision or process change, COC required with every production shipment, and dimensional inspection records available on request. Suppliers who cannot meet these requirements or who treat documentation as an exceptional request rather than a standard service are signaling that their quality system is not operating at the level required for OEM production programs. PW Marine OEM provides all standard quality documentation as part of every marine hardware program, not as an add-on. Full documentation capabilities are described on our quality systems page.
Request a quote — or bring us your full Bill of Materials. Most programs start with one part category and expand from there.
Related Purchasing Topics
- Marine Hardware Supplier Qualification Framework
- The 12 Questions Boat Builders Ask Marine Metal Fabricators
- 304 vs 316 Stainless Steel in Marine Environments
- Marine OEM Parts Lead Times: Avoiding Production Delays
- How to Consolidate Marine Hardware Suppliers