Fitting and removal of rivet

The plates were held on by a Hammer Drive Screw — that is to say a screw that is fitted by using a hammer into an interference-fit hole. They are threaded, although the block is not. If you want to remove, do not chisel off and hope to drill out the remains – they go so hard as to resist a drill and require a spark eroder to remove.

First, soak with penetrating oil and tap the head of the screw to loosen the bond it has with the head. Removal will be easier if you turn the head of the screw anti-clockwise to remove it. Taking care if you want to retain the existing plate, get a pry bar, chisel or screwdriver (depending on your level of technicality) under the head of the screw (damaging the aluminium of the plate a little) to start it. This will allow you to hold the head of the screw – shown here using a pair locking pliers (Mole grips) to pull and turn whilst removing it. You can sometimes remove just by careful application of a pry bar. The main thing is not to shear it off

Re-fitting just requires hammering in, although I would recommend some oil or grease to make removal easier if ever needed. If the old screws have been sheared off, you will have to drill two new holes to one side or cut the heads off the new screws and glue the whole assembly onto where it should go.

This is courtesy of Tim harbour who supplies new correctly stamped engine number tags which are available to order from Mini Spares by request.