Commissario
Reading the above reminded me, if there is a farm/agricultural supply place near your they can often do quite good prices on fixings and fittings, there is one near me where they do all sorts and IIRC for the smaller stuff it's usually a case of you pick up a bag and create what is effectively a high iron content pick and mix, complete with the guys at the counter weighing your bag to work out the price.
Last time I needed a few locking washers I think I paid pennies for a couple of dozen.
Last time I needed a few locking washers I think I paid pennies for a couple of dozen.