hole saw drill bit further adds to the level of security that prevents damages and accidents in terms of dimension the sizes of various parts of the drill safety system may vary according to drill beings used the intended drilling results and the size and the shape of the workpiece the collecting cup 60 is preferred to provide sufficient coverage of the drilling site 240 the covered area of the collecting cup 60 measure by the area within the cup rim 63 is preferred to range from 1 cm 2 to 1 m 2 with the more preferred range of 10 to 200 cm 2 the overall length of the vacuum unit 50 may range from 10 cm to 5 m with the preferred range of 30 to 100 cm when the magnetic unit 10 has a ring shape as indicated in fig3 5 the inner diameter may range from 1 cm to 1 m with the preferred range of 5 to 30 cm the outer diameter may range from 1 cm to 1 5 m with the preferred range of 5 to 50 cm and the ration of outer diameter inner diameter may range from 1 1 to 5 with the preferred range of 1 2 to 2 5 the length 99 of the hole saw 95 may range from 0 5 to 100 cm with the preferred range of 1 to 20 cm it is preferred that various parts of the drill safety system are not too heavy so that they may be held transported and used with easy in particular the vacuum unit 50 is preferred to be light because in some cases a user is supposed to hold the vacuum unit 50 during drilling the overall weight of the.