5 mm dia drill bit
A 4 mm drill bit is equivalent to 5/32 inch.
the answer you seek is a 5 mm, - or a tiny fraction over 3/16 inch.
If you are hoping to insert a 5mm anchor, the hole must be close. I would drill a 5mm hole.
I use a 5/32 drill bit for an 8 gauge screw.
I use 1/4 drill bit for a 5/16 lag screw in most materials.
An 'O' drill bit is a decimal size, 0.3160 inch, which is between 5/16 and 21/64 on the fractional inch scale.
5 mm = 0.1969 inch (rounded) Direct Conversion Formula 5 mm* 1 in 25.4 mm = 0.1968503937 in
I would use a 5/8 drill bit which is almost exactly 16mm.
3.5mm is almost exactly 5/32inch
8mm is almost exactly 5/16 inch. The wrenches are interchangable.
without being exact-- I believe it is about 1/8ANS 2 - Not wanting to be a nit-picker, but it's actually 5/32 almost exactly.