This milled aluminum mold is for the production of spike leads weighing 100-125-150-175 grams, inserting the 2 mm diameter rods automatically creates the holes to house the hooks. https://www.abbocca.com/images/piombi/stampo_spike.jpg The recesses are partly made on the mold partly thanks to the insertion of some steel spheres with a diameter of 6.3 (which we supply together with the mould, even a few more in case of loss, however they can be easily found...) positioned on the die.