Saw on FB an add for a set of 5 fostner hole drills , arrived today and I'm very impressed nice carry case and fitted with a depth stop on each drill that's removable, tungsten carbide tipped and hexagonal shank so no slipping in drill the 5 sizes are 15mm,20mm,25mm,30mm and 35mm which is ideal for blum hinges £8.99 +pp+vat will post after Christmas how they perform