Yes counterbore and countersink at the entry to threads are common on heat treated / highly stressed threads. Not having this functionality makes it hard to make a proper parametric drawing callout as the chamfer dims don't allow for a normal CS_diameter x 90deg callout. LikeReply Log In...
like most wood screws. The other important thing is to always drill a pilot hole first, then a clearance hole and then the counterbore or countersink. If you don't drill a proper clearance hole, the screw will try separate the two parts you're trying to screw together. It'll also make...