Yes, an MOT tester will have a small hammer tool called a 'Corrosion Assessment Tool' or CAT for short, a VOSA-approved MOT test hammer.
The CAT is a VOSA-approved MOT test hammer that is used by MOT testers. It is a small tool that is used to check for corrosion on the car's surface. The CAT is used to check for signs of rust and corrosion on vehicle bodywork, including windows, bumpers, skirting and exhausts.
The actual head of this hammer is made out of a type of hard-wearing plastic which can be used only on suspect corroded and weakened areas of the vehicle. By using this type of MOT tool, you can avoid causing unnecessary damage to the surrounding surface adjacent to which you are using the Corrosion Assessment Tool (CAT).
Needless to say, a standard hammer cannot be used during an MOT test, and the tester cannot intentionally damage the chassis or vehicle bodywork, but only discover if there are hidden problems otherwise not seen to the naked eye, that may cause serious vehicle failure or danger in the coming year.