This International Standard specifies acceptance levels for indications from imperfections in ferromagnetic steel welds detected by magnetic particle 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 this International Standard are based on detection capabilities that can be expected when using techniques specified in ISO 17638 and parameters recommended in Annex A. 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.