Patent ID: 6138540
Filing Date: 2000-10-31
Classification: B23B,B23G,Y10T

Abstract:
Method for producing a thread in a rotary work piece, wherein a threading insert, including at least one cutting corner having a peripheral edge, creates the shape of the thread through a number of passes along the work piece during radial infeed, wherein the method comprises the following steps:providing the cutting corner with two cutting tips along its peripheral edge, each cutting tip including a radially, outwardly extending projection, said projections each extending a length in a radial, outward direction from a first imaginary line, said first imaginary line defined as a line drawn perpendicular to a bisector of adjacent flank edges of said cutting tips, wherein said lengths are different, each said cutting tip comprising a cutting edge, which is provided to form a thread top substantially between the cutting tips, wherein the total, projected length of the cutting edge is made less than two thread pitches,feeding the threading insert radially inwardly during simultaneous rotation of the work piece,passing the work piece a number of times with increased depth of infeed at each pass, wherein the cutting tips are brought to co-operate for cutting a top of a thread profile.