ISO 23277:2015 specifies acceptance levels for indications from surface breaking imperfections in metallic welds detected by penetrant testing. The acceptance levels are primarily intended for use during manufacture examination, but where appropriate, they can be used for in-service inspection.

The acceptance levels in ISO 23277:2015 are based on detection capabilities that can be expected when using techniques specified in ISO 3452 series and parameters recommended in annex. The acceptance levels can be related to welding standards, application standards, specifications, or codes. Such a relationship is shown in ISO 17635 for ISO 5817 and ISO 10042.

Acceptance levels for grouped indications are not covered by ISO 23277:2015.