Manufacturers who want to apply the API monogram on their equipment and materials must apply to API for a license to do so. If API determines, through an on-site audit, that a manufacturer has the capability to produce products that consistently conform to API specifications, API shall license that manufacturer to use the API monogram and their license number on specific products made at specific locations. Although any manufacturer may claim that its products meet API specifications without monogramming them, only manufacturers with a license from API can apply the API monogram to their products.

When the API monogram, in conjunction with the manufacturer’s license number, actually appears on the product, it constitutes a warranty by the licensed manufacturer (licensee) to the American Petroleum Institute and to the purchaser of such equipment or materials: that the product complies in every detail with the applicable standards and specifications. No such warranty to API exists when the monogram does not appear.

API does not recognize claims about API-specified products to which manufacturers do not apply the monogram. Users who want an “API standard product” from an API licensed manufacturer should require in their purchase order that the monogram and the manufacturer’s license number appear on the product itself.

The API evaluation and licensing system has superiority to other quality system evaluations — such as ISO 9000 — because API issues Monogram Licenses only after an on-site audit has verified both: that the licensee’s quality management system conforms to the requirements described in API Specification Q1 in total, and that manufactured products bearing the API Monogram meet the requirements of individual API product specifications. In contrast, other systems do not require auditors to verify product conformance to individual specifications

Woodco USA has license certificates, API 6A and 16A. For a list of manufacturers API has licensed to date, see The API Composite List, Latest Edition, updated weekly, online at For more information on the American Petroleum Institute, visit