Abstract: The invention concerns inner spring assemblies for mattresses, typically bed mattresses. The invention proposes an inner spring assembly having open-ended coil springs arranged in first rows and second rows transverse to the first rows and a connecting arrangement which connects the coil springs to form a unitary assembly. For ease of manufacture all the coil springs in the assembly are of the same hand, those in the first rows are oriented similarly to all other springs in the same first row and in at least some of the second rows there are springs which are oriented oppositely to other coil springs in the same second row.