This machinist patent shirt is for Patent #4,276,692 issued in 1981 for Kant-Twist clamps produced by Clamp Manufacturing Company, Inc. If you are like me, you use these Kant-Twist clamps almost daily.
From abstract of the Kant-Twist clamps patent:
Clamp capable of mechanical clamping and optionally useful for providing especially high electrical conductivity having a pair of juxtaposed clamping jaws for gripping an object. One important use of the clamp is to grip an article through which high current is required to flow as, for example, in electric welding. At least one of the jaw blocks is of deep case-hardened cold rolled steel, and when used for high electrical conductivity, is copper coated. The face of this block is provided with concentric teeth which bite into the article. The outer faces of the teeth are perpendicular to the surface of the article being gripped.
Show your pride of Kant-Twist clamps with this 100% cotton t-shirt (except for heather colors, which contain 10% polyester). Pre-shrunk to make sure your size is maintained throughout several washes, and a classic fit.
• 100% jersey knit
• Seamless, double-need ⅞” collar
• Taped neck and shoulders
• Classic fit