ISO 5817 Quality Levels B, C and D: What They Mean

Find the specified level first

The inspector should not choose a quality level after seeing a result. Establish the level required by the drawing, product standard or contract, and the applicable edition. Where a project assigns different requirements to different joints, retain that mapping in the inspection plan.

A quality level is not a universal statement of fitness for every service condition. The standard concerns production quality and workmanship; the designer and governing requirements determine suitability for the application.

Use the right examination and acceptance reference

Agree which imperfections the examination is intended to reveal and which method-specific acceptance rules apply. A visual dimension and an ultrasonic response are different observations. Do not convert a UT amplitude directly into a workmanship limit without a valid basis.

Keep the examination procedure, coverage and reporting threshold distinct from the final acceptance decision. If the method cannot assess a specified feature, identify that limitation before declaring the joint acceptable.

Make the record reproducible

Identify the joint, drawing revision, specified level, examination method and reference used for the decision. Describe each reportable indication with its location and measured characteristics. Record any repair and re-examination against the same joint identity. Use a licensed copy of the applicable standard for limits; a short web summary cannot reproduce its tables and conditions.

References and next steps

ISO 5817: scope and published edition provides further background. Use the governing specification and approved procedure for the actual job.

Discuss the examination scope. Include the component, material, service history and decision the inspection needs to support.