The washer/spacer is with overall dimensions of 8x18mm, designed for a 1/4" 19mm long screw, but it can be easily modified to meet your needs, as long as the fastener has a countersink head. Through the User Parameters in Fusion 360, all the necessary dimensions can be adjusted; however, the finishing details (e.g., chamfers and fillets) must be modified in the Timeline.

The Step and Fusion 360 files are also here.