On Monday, February 5, 2018 at 7:01:33 PM UTC-8, Charles Longley wrote:
Yeah I didn’t punctuate that correctly. It should have read- “ They need to be aircraft screws. Hardware store screws have the wrong taper on them.

One example a part number of a countersunk metric screw is 22256BC040010L.
22256 is the type of screw,
BC is the metal type,
040 is the diameter,
010 is the length,
If you google the part, number lots of suppliers come up. If you need a few, contact a helicopter operator that maintains Eurocopter Astar AS350 helicopters. There are thousands in the US, if that is where you are. there may be one close to see what you are getting.
Rob