Sash Heritage Dual Screw with Key - 70mm - Polished Chrome

This Sash Heritage 70mm Dual Screw complete with Key is part of our Sash Window Restrictor range.Available finishes: Antique Brass, Antique Nickel, Black, Bronze, Polished Chrome, Polished Brass, Satin Chrome, Satin Nickel.Fitting Instructions:It is usual to fit two of these locks on sliding sash windows unless they are small. With the window in the closed position, mark the position of each lock on the horizontal rail of the inner sash. Then mark the half-way point between the top and bottom of this rail at these positions. Before drilling, double check that the hole will not catch and crack the edge of the glass. If needs be, oset the lock slightly to clear the glass.Using a drill bit of the recommended diameter, drill into the inner sash and on into the horizontal rail of the outer sash. The depth of the hole in the outer sash will be detailed with the lock, but this will usually be around 18mm. In order to avoid over drilling, use a depth gauge mounted on the drill and set to the required overall depth. If you don't have one of these, simply wrap a small piece of tape around the drill bit at the right depth and stop when the tape reaches the surface. Open the sashes and clean out all the residual sawdust. A vacuum cleaner does an excellent job of clearing this.Insert the barrel for the inner sash into the hole and tap it home so that it is ush with the surface. Use a small block of wood on it so as to prevent damage from the hammer. Some windows - particularly older ones with thinner glass can be quite fragile. For these, you can push the barrel into the sash by holding a clamp around the two and tightening it till the barrel sits ush. Repeat the process with the outer shorter barrel.Close the window sashes and insert the bolt into the barrels and use the key provided to secure it. Depending upon the lock and the window sizes, it may be necessary to shorten the bolt. This can easily be done by holding the bolt in a bench vice and trimming with a hacksaw