Wera 05104672001 843 stepped drill bit 4 to 20mm wera 05104672001 this stepped drill bit from wera has 9 drill steps ranging from 4mm to 20mm and is suitable for use on material up to 4 5mm thick this bit also has an edge breaker for use on 1mm sheet metal wera 05104672001 843 stepped drill bit 4 to 20mm