Patent ID: 8196493

Claim:
A method for manufacturing combination wrenches comprising: preparing a material plate including first and second edges spaced in a width direction and top and bottom edges extending between the first and second edges, with the top and bottom edges spaced in a length direction perpendicular to the width direction, with the material plate further including upper and lower faces extending between the top and bottom edges and between the first and second edges, with the upper and lower faces defining a thickness therebetween in a thickness direction perpendicular to the width and length directions, with the material plate including a plurality of wrench material pieces arranged in the length direction, with each of the plurality of wrench material pieces including first and second ends spaced in the width direction and an interconnecting section interconnected between the first and second ends; shearing each of the plurality of wrench material pieces from the material plate; pressing each of the plurality of wrench material pieces in a sealed mold at a temperature without generating carbon scale to form a wrench semifinished product, with each of the wrench semifinished products including first and second driving ends formed from the first and second ends of one of the plurality of wrench material pieces, with each of the wrench semifinished products further including a handle interconnected between the first and second driving ends and formed from the interconnecting section of one of the plurality of wrench material pieces, with each of the wrench semifinished products further including upper and lower surfaces extending between the first and second driving ends and spaced in the thickness direction, with the first driving end of each of the wrench semifinished products having a height between the upper and lower surfaces and not larger than the thickness of the material plate, with the second driving end of each of the wrench semifinished products having a height between the upper and lower surfaces and larger than the thickness, with the handle of each of the wrench semifinished products having a first height between the upper and lower surfaces adjacent the first driving end, with the handle of each of the wrench semifinished products further having a second height between the upper and lower surfaces adjacent the second driving end, with the first height smaller than the height of the first driving end, with the second height smaller than the height of the second driving end; and processing the first and second driving ends of each of the wrench semifinished products to form a combination wrench having two ends with different shapes.