Well, a nut might be too hard to crack; I would suggest a screw, but, I think you would get the implications of that. A button, a bolt, a washer, a thing-a-ma-jig, a-what-cha-ma-call-it, or a whirlygig might suffice, but, a roll of the dice might cause the Medium Help Desk to fear accusations of just playing Craps.