I made the mistake of handing over the lug nut key to Costco when getting new tyres instead of taking them off myself. They went at it with an air ratchet and exploded the end. Fortunately they had one lug nut off so I was able to measure the notches and machine a new one. Six 3/16" x 1/2" dowel pins serve as the drive.
This style lug nut is apparently no longer available, besides four lug nuts and matching key would be needed since they came in several patterns and there is no marking on the key or lug nut to indicate which pattern.
In an emergency, a single pin is all that is needed to remove the lug nut.
