Machinery's Handbook, 31st Edition
WING NUTS, WING SCREWS AND THUMB SCREWS 1929 nuts may be somewhat larger than the Unified Thread Class 2B maximum but shall in no case exceed the minimum pitch diameter. Materials and Finish for Wing Nuts.— Types A, B, and D wing nuts are normally sup plied as specified by the user in carbon steel, brass or corrosion resistant steel of good quality and adaptable to the manufacturing process. Type C wing nuts are made from die- cast zinc alloy. Unless otherwise specified, wing nuts are supplied with a plain (unplated or uncoated) finish. Wing Screws.— A wing screw is a screw having a wing-shaped head designed for manual turning without a driver or wrench. As covered by ANSI/ASME B18.17-1968 (With- drawn) wing screws are classified first, by type on the basis of the method of manufacture, and second, by style on the basis of design characteristics. They consist of the following: Type A: Type A wing screws are of two-piece construction having cold formed or cold forged wing portions of moderate height. In some sizes they are produced in regular, light, and heavy series to best suit the requirements of specific applications. Dimensions are given in Table 5. Type B: Type B wing screws are of hot forged one-piece construction available in two wing styles: Style 1, having wings of moderate height; and Style 2, having high wings. Dimensions are given in Table 5. Type C: Type C wing screws are available in two styles: Style 1, of a one-piece die-cast construction having wings of moderate height; and Style 2, of a two-piece construction having a die-cast wing portion of moderate height. Dimensions are given in Table 6. Type D: Type D wing screws are of two-piece welded construction having stamped sheet metal wing portions of moderate height. Dimensions are given in Table 6. Materials for Wing Screws and Thumb Screws: Type A wing screws are normally sup plied in carbon steel with the shank portion case hardened. When so specified, they also may be made from corrosion resistant steel, brass or other materials as agreed upon by the manufacturer and user. Type B wing screws are normally made from carbon steel but also may be made from corrosion resistant steel, brass or other materials. Type C, Style 1, wing screws are supplied only in die-cast zinc alloy. Type C, Style 2, wing screws have the wing portion made from die-cast zinc alloy with the shank portion normally made from carbon steel. Where so specified, the shank portion may be made from corrosion resistant steel, brass or other materials as agreed upon by the manufacturer and user. Type D wing screws are normally supplied in carbon steel but also may be made from corrosion resistant steel, brass or other materials. Thumb screws of all types are normally made from a good commercial quality of carbon steel having a maximum ultimate tensile strength of 48,000 psi (331 MPa). Where so spec ified, carbon steel thumb screws are case hardened. They are also made from corrosion resistant steel, brass, and other materials as agreed upon by the manufacturer and user. Unless otherwise specified, wing screws and thumb screws are supplied with a plain (unplated or uncoated) finish . Thumb Screws.— A thumb screw is a screw having a flattened head designed for manual turning without a driver or wrench. As covered by ANSI/ASME B18.17-1968 (With- drawn) thumb screws are classified by type on the basis of design characteristics. They consist of the following: Type A: Type A thumb screws are forged one-piece screws having a shoulder under the head and are available in two series: regular and heavy. Dimensions are given in Table 7. Type B: Type B thumb screws are forged one-piece screws without a shoulder and are available in two series: regular and heavy. Dimensions are given in Table 7.
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