ANSI BHMA A156-7:2003 pdf download.AMERICAN NATIONAL STANDARD FOR TEMPLATE HINGE DIMENSIONS
2.1 Scope: This Standard covers the requirements for the length, width, thickness, offset, and screw hole spacing for builders template hinges. Included in the standard are hinge identification symbols and screw sizes. Methods for identifying template hinges that conform to the Standard are provided.
3.1 General: Products represented as complying with this Standard shall meet all of the requirements specified herein.
3.2 Types, Sizes, and Dimensions: The types, sizes, and dimensions of the hinges covered by this standard shall be as specified in Figures 1 through 24. The figures are for illustration only to assist in identifying the hinge types and in locating dimensions. All dimensions are in inches and millimeters. The figures do not show requirements for the design, type of bearings, or contour of the offset. The tolerances for the specified dimensions shall be as follows
3.2.1 V ariable dimensions: The offset dimensions and machine screw sizes are included with the template dimensions for each hinge. Hinges that are represented as conforming to this Standard and which comply with the template dimensions but vary in the recommended screw sizes, shall be accompanied by information clearly describing the variation. The off-sets shown herein for half surface, half mortise and all swing clear hinges may be smaller or greater according to the individual manufacturer's regular practice, provided that the widths of affected leaves are changed to conform with any increase or decrease in offset. The template dimensions shall not be affected by such modifications.
3.2.2 Template identification symbols: The first letter of the symbol indicates the thickness:A = Standard weight and B = heavy weight. The next two digits indicate the vertical height of hinge; for example, 20 = 2 inch (50.8 mm), 25= 2 1/2 inch (63.5 mm), 30 = 3 inch (76.2mm), 35 = 3 1/2 inch (88.9 mm), etc. The last letter(S), indicate(s) the type of hinge: M = full mortise, H = half surface, HM = half mortise and S = full surface，SMA = slip-in with one leaf in cavity (normally jamb leaf), SMB = slip-in with both leaves in cavities, the suffix S added to M, H, HM or S = swing clear in full mortise half surface, etc. Thus A45MS indicates a standard weight full mortise swing clear hinge in4 1/2 in(114.3 mm) size.
3.4 Half Surface, Full Surface and Half Mortise Hinges: The surface leaves of full surface, half surface and half mortise hinges shall have beveled edges. The mortise leaves of half mortise and half surface hinges shall have straight edges and square or radius corners.ANSI BHMA A156-7 pdf download.