GlossaryKind of term: Manufacturing termCertificate of conformity (CoC)
What is a certificate of conformity?
A certificate of conformity is your signed statement with a delivery that the parts were made to the drawing, revision and order.
Usually called the CoC, it is a short document that travels with the shipment. It carries order number, part number with revision, quantity and date, signed by someone authorised to do so. It often refers to the heat number of the material and to the certificates for outsourced operations such as anodising or hardening. It holds no measured values.
What does the standard say about a certificate of conformity?
ISO/IEC 17050-1 gives a general framework for a supplier's declaration of conformity, but in practice the content is set mostly by the customer's order and purchasing terms. For metallic products, EN 10204 has a comparable declaration, type 2.1: compliance with the order, without test results. Type 3.1 is a different document: an inspection certificate with test results, validated by a representative independent of the manufacturing department.
How does a certificate of conformity work in practice?
Drafting a CoC is little work, but the statement is only as strong as the records behind it. Whoever signs must be able to trace which material, which revision and which inspection belong to the delivery; that takes the certificates from material supplier and finisher on every order. The time falls per delivery, not per part, and under a framework agreement it comes back with every call-off. If the customer wants an inspection report as well, those are two items.
What is a certificate of conformity often confused with?
A certificate of conformity is not a material certificate: that covers a batch of material, the CoC covers your parts. The EU declaration of conformity behind CE marking is separate too: it is drawn up by the manufacturer of a product that falls under EU product legislation, such as a machine, not by the supplier of a single part.
Frequently asked questions
What should a certificate of conformity contain?
Whatever the customer specifies. Usual contents are your company name, the customer, order number, part number with revision, quantity delivered, a statement that the parts meet drawing and order, references to certificates, the date and an authorised signature.
Is a CoC the same as a 3.1 certificate?
No. A 3.1 certificate under EN 10204 is an inspection certificate with test results for a batch, usually from the material producer. A CoC is your statement about the delivered parts, without measured values.