When purchasing any crowbar, you should be on the lookout for manufacturing defects such as the burr shown opposite.
Burrs occur when strips of metal fold away from the blade during machining. A defect like this one indicates that the nail slot was not deburred after machining, and renders the bar unusable.
Additionally, it reveals a subpar manufacturing process in which steps have been missed and post-production inspection is lacking – even if a burred bar were to be usable, it should be avoided in favour of a better quality of manufacture.
If you own a burred bar and do not have the option of returning it to the seller, you can deburr the nail slot yourself using a grinder – but if you don’t already have the necessary tools for deburring, it would be much cheaper to buy another bar.