These flanged head pozi pan self tappers are ideal for securing car trim, fabric, plastic or other thin materials and are often referred to as trim screws.  They have been very useful in refurbishing a Mazda Bongo so we can vouch for their longevity. Cross recessed drive suiting pozi drive type screwdrivers.

As the name suggests, this type of screw forms its own thread as it is installed into a pre-drilled hole. Not to be confused with self drilling screws, the main difference is that self-tapping screws cannot go through metal without a pilot hole, which must be pre-drilled or pre-punched.

Exact drill or punch hole size is also important. The screw will become loose and not thread properly and securely if the hole’s too big. If the hole’s too small, the screw can break or cause the material to split or crack.

This set contains a selection of  of No.4, No.6, No.8 and No.10 (2.9mm, 3.5mm, 4.2mm & 4.8mm thread diameter) screws. They are type C (AB) which is the sharp pointed version.

Black oxide plated mild steel has a limited resistance to the elements so best suited to internal applications. It is harder than stainless steel, however, and can be tightened with greater force.