openscad module to model countersunk screw (with head), useful for subtracting when constructing attachment bores

screw_countersunk.scad

// model countersunk screw for 3d printing
// useful for creating attachement bores
// which fit these screws
// default values are for 3mm x 20mm screw with 6mm head (3.2mm bore for tolerance)
module screw_countersunk(
        l=20,   //length
        dh = 6,   //head dia
        lh = 3,   //head length
        ds = 3.2,  //shaft dia
        )
{
    union() {
        cylinder(h=lh, r1=dh/2, r2=ds/2, $fn=6);
        polyhole(h=l, d=ds);
    }
}