We supply these tricky custom 17-7PH springs to our aerospace customer - unlike the other compression and extension 17-7PH springs we supply the same customer, these are C shaped with two .165" length oval openings.  The material thickness was set to .020" and the outside diameter at .550-.555".  The angle between the ends was the more challenging part, set at 130 +/-5 degrees.  The oval openings incorporated a full radius on both sides and the width was limited to .062" max.  A FAIR and material certs were provided with the parts.