Lubricant - SD-40 (200ml)

The 200 millilitre can of the penetrating spray Hatch stocks as both BS-40 and SD-40 - the same lubricant in three sizes, of which this is the middle. Two hundred millilitres is the van and toolbox size: more than the small can for somebody who uses it most days, without the bulk of the 400ml on a workshop bench. It frees seized bolts and rusted mechanisms, silences hinges and pivots, drives water out of damp electrics and ignition, and lifts grease and adhesive residue off metal. Soak a seized fastener properly and give the penetrant a few minutes to creep into the thread before applying force - that waiting is what makes the difference between a bolt that turns and a head that rounds off.