Magnetism is especially problematic for customers who realize many machining operations because the copeau can remain sticked on the bar and cause disturbances in the start of production. If the bars are sheared and forgings, there is no risk of disturbance. If the bars are sawed or machined, there may be disturbances ..
If you do not impose maximum tolerance on magnetism, there is little risk for that, on your specification, it is not specified the maximum value for it, it is preferable to impose the maximum value in order not to exceeding.