Thought i would ask before before digging out the yellow pages. I need 8 x thread adapters to fit some spikes to speakers. Already have the speakers and spikes/cones. Speakers have 1/4UNC and cones have 3/8UNC. So i need a stud, with 10mm of 3/8UNC one end and 15mm of 1/4UNC at the other. Measurements are approx, if anyone can help i can send a diagram. TIA.