by other connectors as for example as illustrated in fig7 by barbs 24 formed on the inside edge of the downwardly extending sections 19 of the channels 17 formed in the valleys 16 of the support wires 13 in the event that barbs formed in the channels 17 of the support wires are used to connect the wire core 4 to the base frame 2 the completely assembled core may be simply pressed downwardly onto the base frame 2 to secure the assembled wire core to the base frame with the barbs 12 locked into the sides of the slats 3 with particular reference now to fig2 and 4 it will be seen that the support wires 13 are arranged in pairs with each pair having riser sections 22 extending downwardly and inwardly from the top peak sections 15 in one embodiment of the invention these pairs of support wires define an included angle of approximately 35 u00b0 therebetween as illustrated in fig5 this included angle between the pairs of support wires 13 facilitates nestable stacking of the assembled wire cores for shipment or storage before these assembled wire cores 4 are secured to base frames with reference to fig6 and 7 the slats 3 of the base frame 2 are there illustrated as being secured on edge as for example by nails not shown to the side boards 26 of the base frame 2 this differs from the slat of fig1 4 wherein the slats are illustrated as lying flat on.