ASTM_D_6193_-_11.pdf

Designation:D619311Standard Practice forStitches and Seams1This standard is issued under the fixed designation D6193;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This practice covers the requirements and characteristicsof stitches and seams used in the fabrication of sewn items.1.2 This practice identifies the category,formation,andgeneral purpose for stitch types and seam types used in thefabrication of sewn items.1.3 Subsequent to a general discussion of stitches and seamsthat include schematic indices,this practice is comprised of thefollowing sections that are listed in the order in which theyappear:1.3.1 Section 5Classification of Stitch Types for whichdrawings are shown in Stitch Figs.1-69,1.3.2 Section 6Classification of Seam Types for whichdrawings are shown in Seam Figs.70-288,and1.3.3 Annex A1Seam Assembly Recommendations.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to Textiles3.Terminology3.1 Definitions:3.1.1 bartack,na reinforcement stitch that effectivelyminimizes tearing at the ends of critical stress stitchlines.3.1.1.1 DiscussionExamples of critical stress stitchlinesinclude:ends of seams,zippers,pocket flaps,crotch/seatseams,collars,webbing and other components.If the bartack-ing process exhibits an insufficient number of stitches,im-proper thread size relationship or shortened bartack stitchedlength then it will fail under stress.Bartacking,because of thestitch density,can exhibit severe needle-cutting,thus creating aself-destructive characteristic if number of stitches isexcessive,or sewing needle or thread size is too large forfabric.Bartacking is specified strictly as a relationship betweenlength,width or throw and total stitches.It does not incorporatestitches per inch as a typical seam may specify.3.1.1.2 DiscussionCounting finished bartack stitches isvirtually impossible since the overall process consists of threecomponents.The process begins in a horizontal position toachieve the required length and then forms the familiar zig-zagstitch-line along the horizontal plane including backstitching atboth ends to lock in the zig-zag stitches to prevent raveling.The zig-zag stitches criss-cross the initial horizontal stitch linethus virtually hiding the initial stitch line.3.1.2 needle damage,nin sewn fabrics,the partial orcomplete yarn severance or fiber fusing caused by a needlepassing through a fabric during sewing.3.1.2.1 DiscussionThis can also be referred to as needlecuts.3.1.3 seam,na line where two or more fabrics are joined,usually near the edge.See also sewn seam,glued seam,stapledseam,thermally bonded seam.)3.1.4 seam allowance,nin sewn fabrics,the distance fromthe edge of a fabric to the parallel stitch line furthest from thatedge.3.1.5 seam assembly,nthe composite structure obtainedwhen fabric(s)are joined by means of a seam.3.1.6 seam damage,n in sewn fabrics,an adverse changein the physical condition of one or more of the components ina seam which would reduce the seam acceptability such as yarnslippage,needle damage,or fabric rupture.3.1.7 seam effciency,nin sewn fabrics,the ratio of seamstrength to fabric strength.3.1.7.1 DiscussionFor some constructions,yarn strengthand stitch type can contribute to a higher seam efficiency value.3.1.8 seam slippage,nin sewn fabrics,the displacementof the fabric yarn parallel and adjacent to the stitch line.1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.54 on Subassemblies.Current edition approved Jan.1,2011.Published May 2011.Originally approvedin 1997.Last previous edition approved in 2009 as D6193 09.DOI:10.1520/D6193-11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.9 seam type,nin sewn fabrics,an alphanumeric des-ignation relating to the essential characteristics of fabricpositioning and rows of stitching in a specified sewn fabricseam.3.1.10 sew,vto unite or fasten with stitches.3.1.11 sewing thread,na flexible,small-diameter yarn orstrand,usually treated with a surface coating,lubricant,orboth,intended to be used to stitch