These custom slotted flat copper machine screws are one of multiple sizes we have supplied our electronics customer over the years.  They are custom made each time as ordered due to relatively small usage and are typically shipped within 2-3 weeks of order.  This specific 4/40 X 5/16 version was produced domestically at 5,000 pcs under our internal part number MSF-0405-Z.  Material certs are made available upon request and expedited processing is typically available, depending on raw material availability.