ASME B107.16M:1998 pdf download SHEARS (METAL CUTTING, HAND)
3.4 Identif cation Marking
All shears shall be marked in a plain and permanentmanner with the manufacturcr’s name or with a trademark of such known character that the source of
manufacture may be readily determined.
3.5 Finish
Shears may have a painted, lacquered, enameled,plated, black oxide, or natural finish.
3.6 Blades
Except for the cutting edges, all other blade cormersand edges shall be smooth and rounded. Blade bearingand mating surfaccs shall be ground truc and shall besmooth They shall be of ample width to prevent theblades from twisting or springing open under ordinarycutting loads likely to be encountered in service.
3.6.1 Type I Shears, Blade cutting edges shall besharp, suitably beveled, and properly hardened andtempered. Cutting edges shall be so designed that theproper cutting angle shall be maintained throughout thefull length of cut.
3.6.2 Type II Shears. The blades on Type Il shearsshall have one or two serrated cutting edges and shallbe curved in the cutting (shearing) plane, Serrationsshall be of suffcient depth and shaped to ensure thatthe requirements of para. 4.6.3 are met. The serrationsshall be evenly spaced and well-defined throughout theeffective length of the cutting blade. Blades shall bedesigned to divert the sheared portion of the metalaway from the handles
3.6.21 Requirements. Blades shall be madefrom high carbon steel having 0.75% carbon, min,oralloy steel with at least 0.60% carbon content and atleast a total of 0.20% alloying elements (excludingmanganese). Blades shall have a hardness from 55 to61 HRC,and matching locations on the blades of anyone pair of shears shall be within 4 HRC. Readingsshall be taken within 012 in.(3.1 mm) from the
cutting edge.
3.7 Pivot Fastener and Tensioning FastenerThe center fastener shall serve as a pivot joint holdingthe blades together and shall provide a mcans formaintaining blade adjustment,The tensioning fastenermay be of a self-locking type or jam type if the pivotfastener is threaded into one blade.
3.7.1 Pivot Fastener Material. The pivot fastenershall be of high shears strength material. The bearingsurface finish (shank portion) shall not exceed 63 in(1.6 m) when tested in accordance with ASME B46.1
3.7.1.1 All Type I shears, pivot fasteners, andType Il shears tensioning fasteners shall be made inaccordance with one of the following optional require-ments:
(7)hardened from 30 to 40 HRC(2) case hardened from 83 to 90 HR15N with aminimum case depth of 0.007 in.(0.18 mm)(3)unhardened material having a minimum tensilestrength of 80,000 psi (552 MPa)
3.7.1.2 The center pivot fastener of Type II shearsshall be material having a minimum tensile strengthof 150,000 psi (1035 MPa) and a hardness of 32 to39 HRC.
3.8 Handles for Type I and Type Il
Handles shall be shaped to provide a smooth andcomfortable grip for the hand. Handles shall be freefrom flash and irregular or sharp projections and edges.All shears shall be provided with stops arranged topreclude the possibility of the handles being closedbeyond the effective blade cutting point.