These are custom captive stainless steel screws we supplied to our construction customer, who refers to them as “Gripper Screws”.  Production was done domestically in the USA at approximately 5,000 pieces and a lead time of 6-8 weeks.  The multi-step flat head was made using a cold heading process and the 10-32 thread was rolled at 0.2″ in length.  The diameter of the unthreaded shoulder was set at 0.14″ +/-.015.