Many products have elements of quick fixing which uses a special manual nut or screws with knurled head. Losing such detail — it is simple, but to pick up then another of the same — much more difficult.
It is easier to make such a fastener from the usual, standard: apply to the faces of the nut or screw head bluntly triangular and rhombic nail file or needle files frequent risks (mutually diagonal or along the axis).
I. GLUKHOV, G. a R a n with it, Mordovia