It can be very confusing when talking about pocket spring counts and mattresses.
The number of springs used in a mattress are based on a king size mattress, so a smaller or bigger mattress will have less or more springs but still be classified as a 1000 or 1200 series.
Make sure the springs are fully heat-treated, as this will prolong the life of the spring. This is achieved by putting the individual springs in a furnace, taking them up to red heat, then quenching. This makes sure the spring in the metal is evenly distributed through the steel.
It is normally agreed by the experts that the optimum quantity of pocket springs in a king-size mattress is 1000 to 1200. This is to allow for a suitable size of coil, as well as the correct thickness of steel. If the coil is too small or the metal too thin, then the support and comfort may suffer. Obviously, the more coils you add the smaller the coil gets and the thinner the steel. More springs doesn't mean better comfort!
It has become a fashion with some manufacturers to offer more and more springs in a mattress - 3000, 4000, 5000 - as a way of trying to impress the customer. This is achieved by adding extra layers or sheets of small diameter mini-springs on the top and bottom of the mattress. These allow the manufacturer to claim a bigger spring count, however this does little to improve the support of the mattress. On the contrary, the mini-springs can stop the large pocket springs underneath acting independently so reducing the springs ability to take up the shape of the sleeper, which is the main advantage of individual pocket springs.
There are also justified ways of increasing the spring count and with it the support, without effecting the size of the spring. One way is to nestle the springs closer together, to produce a honeycomb structure. This will allow the manufacturer to increase the spring count from 1200 to 15000 springs, increasing the support but keeping the spring size the same. (See our Dartmouth)
The other way is to use two complete 1000 spring units, one on top of the other, making the mattress deeper but keeping the spring size the same. This means you are using 2000 springs to create a much deeper and luxurious mattress. (See our Topsham)