No. Reliable fastening with bigHead collar products does not depend on identifying a single ‘correct’ screw pairing. In most cases, there is a range of suitable screws that can be used successfully.
Fastening performance is governed by internal thread loadability, thread engagement, and tightening control. When these factors are managed appropriately, variations in screw grade or property class are unlikely to be the determining factor in pairing compatibility with bigHead collars.