"We used the standard material" — whose standard?
Ask a factory what material they used and you will often hear a reassuring phrase: "the standard one." It sounds like a specification. It is not. It is a moving target.
The "standard" material this month is whatever the purchasing department could source at a good price this month. When markets tighten, the standard quietly slides.
How substitutions happen without any bad intent
- A buyer writes "stainless steel" — the factory reads "whatever stainless we stock" (201 instead of 304)
- A buyer writes "aluminium enclosure" — the wall thickness quietly drops by 0.5mm
- A buyer approves a sample — the bulk run uses a different resin from a different supplier because the first one raised its price
Nobody thinks of themselves as cheating. Everyone thinks of themselves as "being practical." Your product pays the difference.
How to write a specification that cannot slide
1. Name the grade, not the family. Not "stainless steel" — "304 stainless steel, 2B finish, mill certificate required."
2. Name acceptable equivalents. If alternatives are acceptable, list them explicitly. Anything not on the list requires written approval.
3. Require material certificates with each batch. Mill certificates and material test reports cost the factory almost nothing to provide — if the material is genuine.
4. Verify at the 20% checkpoint. Material testing on early production units catches substitution while the run can still be corrected.
The takeaway
Vague specifications do not save time — they delegate your quality standard to someone whose incentive is cost. Write the grade, require the certificate, and check early.
Not sure your specification is tight enough? Send it with your enquiry — we review specs before factories ever see them.*Warren Smith is the CEO of LS International, specifying and verifying materials with Chinese factories.*