Shoe Eyelet Corrosion Testing: An ASTM B117 Buyer Guide

Why corrosion on a small eyelet can matter

An eyelet is a small component, but it sits at the intersection of material choice, surface finishing, installation and consumer use. A visible stain around a lace opening can affect how a shoe looks. A change in surface condition may also prompt questions about assembly, packaging or storage. The right response starts with identifying the actual failure mode instead of assuming that every discoloration has the same cause.

Corrosion behavior depends on the substrate and its surface condition, the deposited coating and any post-treatment, the shape and edges of the component, and the environment to which the finished product is exposed. The way an eyelet is set can also matter: deformation during installation may damage a finish, while contact with another metal, adhesive, textile dye or cleaning chemical can create conditions different from those of a loose component.

For footwear buyers, the most useful first step is to describe the product context. Is the part a brass eyelet, a zinc-alloy hook, a steel washer or a finished assembly? Is it used on a fashion sneaker, a work shoe or outdoor footwear? Will it be exposed to perspiration, rain, storage humidity, salt water or cleaning products? These details guide the test plan and prevent a generic number of chamber hours from becoming a substitute for a product requirement.

What ASTM B117 can—and cannot—tell you

ASTM B117 is a practice for operating salt-spray (fog) test apparatus. The official ASTM listing describes a controlled corrosive environment used to produce relative corrosion-resistance information for metal and coated-metal specimens. It also states that the practice does not prescribe the specimen or exposure period for a specific product, nor how a buyer should interpret the result. ASTM cautions that stand-alone salt-spray results have seldom correlated with natural-environment performance and that correlation is not always predictable. See the current ASTM B117 standard listing and the requirements agreed with your customer or laboratory.

Use a salt-spray test when the customer specification, product risk assessment or agreed qualification plan calls for it. Do not infer chemical compliance, restricted-substance status, corrosion life in the field or suitability for every destination market from a salt-spray result. Those are separate questions and may require different evidence.

The test report should be read as evidence about the sample under the stated conditions. If a brand requires an internal method, a different edition, a particular inspection schedule or a named laboratory, record that requirement before samples are prepared.

Define the test before requesting samples

Before a supplier sends parts to a laboratory, align the buyer, supplier and test provider on what is being evaluated. A short written test plan prevents a common cycle: the supplier tests one finish, the buyer expected another, and both sides later debate what “pass” meant.

1. Identify the component and finish

Record the item or drawing reference, substrate if known, dimensions, color, coating or plating system, any passivation or topcoat, and the intended installation. If the finish is not yet fixed, mark it as a development variable. Ask the supplier to distinguish confirmed construction from a visual sample reference.

2. Name the method and edition

Write down the test method and edition requested by the brand or laboratory. If the project uses a customer-specific method, attach it or identify its controlled document number. Do not assume that “salt spray test” means the same procedure across different buyer specifications.

3. Define exposure and inspection points

State the planned exposure duration and when observations should be recorded. For a project that needs staged review, list the inspection points rather than asking only for a final pass/fail result. The required duration should come from the buyer’s specification or an agreed validation plan—not from a generic website claim.

4. Agree what counts as failure

Describe the acceptance criteria in observable terms: which surfaces are evaluated, what types of corrosion or finish change are relevant, how edges and cut areas are treated, and whether appearance, function or both matter. Include photographs or reference panels if the customer has an approved visual standard. Record who makes the final assessment.

Choose a sample that represents production

A report is only useful for a sourcing decision if the tested sample can be connected to the proposed production specification. Before testing, confirm whether the sample is a loose component, a finished eyelet with washer, or an eyelet installed in the footwear upper. These configurations answer different questions.

Document the finish batch or sample identification, the preparation steps, the date received, and any handling or packaging conditions that could affect the surface. If the test is performed on loose components but the customer’s concern is the installed assembly, discuss whether a second assembly-level evaluation is appropriate. Avoid comparing results from samples that differ in base material, coating thickness, geometry, post-treatment or preparation unless the difference is intentional and recorded.

For development programs, test the same configuration that is expected to be approved. If the finish changes after the report is issued, do not treat the old report as automatic approval of the new construction. Ask the buyer or quality contact whether the change requires a new sample, a risk review or repeat testing.

How to review a corrosion test report

Request the complete report, not just a screenshot of a pass statement. Check that it identifies the issuing laboratory, report number, dates, method and edition, sample description, preparation, exposure conditions, inspection observations and result. Confirm that the tested item can be traced to the part number, drawing revision or approved sample used in the quotation.

If any key field is missing, ask the laboratory or supplier for clarification before using the report for approval. A report for one substrate or finish should not be generalized to every eyelet in a catalog. Likewise, a facility audit and a product test report are different types of evidence and should not be substituted for one another.

Five avoidable sourcing mistakes

1. Specifying only hours. A duration without a method, edition and evaluation criteria is not a complete requirement.
2. Testing the wrong configuration. A loose component may not represent an installed eyelet, washer and upper assembly.
3. Changing the finish after approval. A new coating or post-treatment can change applicability of the earlier report.
4. Treating chamber exposure as field-life prediction. Accelerated test results need context and should not be presented as a guaranteed service period.
5. Using one report for unrelated claims. Corrosion performance does not establish restricted-substance compliance or prove every market requirement is met.

These mistakes can be avoided by tying each requirement to a named product configuration, written acceptance criteria and an approval owner. The supplier can then quote a defined request instead of guessing at a test target.

Copy this checklist into your RFQ

When a requirement is not yet defined, state that clearly and ask the supplier to identify what information is needed to scope a representative test. Confirm all final requirements with the brand, test laboratory and applicable technical or regulatory contacts.