UNF Phillips Fillister Head Machine Screws ASME B18.6.3 in A2 Stainless Steel
UNF Phillips Fillister machine screws have a large cylindrical head, with a slightly convex top surface.
Fillister head screws are the preferred head type for counterbored holes and can also be used for protecting
a surface by raising the level which the screw diver is used to tighten the fixing. They are similar
to a Pan head machine screw, but with greater side height. Height to diameter ratio is larger than a
cheese head. Imperial Unified Fine thread version.