Thread

Many Thin Fibers, One Usable Strand

A single textile fiber is usually too short, too fine and too weak to sew with or to build cloth from on its own. Thread solves that by combination: it is a large number of very thin fibers spun together. Spinning overlaps the fibers and twists them so they grip one another along the length of the strand. Friction between the many fibers, multiplied by the twist, turns a loose bundle that would pull apart into a continuous strand that can be pulled, wound, threaded through a needle and worked without separating. The definition is therefore also a description of manufacture. Change the fibers, the amount of twist or the number of strands combined, and the thread changes with them, becoming finer or heavier, softer or harder, suited to delicate cloth or to heavy material that demands a strong seam.

Used in the manufacture of textiles and in sewing, thread does two related kinds of work. As a material of manufacture it is among the spun strands from which textile goods are built and finished. As a sewing material it is the strand that forms stitches, joining pieces of cloth along seams, attaching trimmings, and closing openings, so the strength and behavior of a garment depend in part on a component most wearers never notice until a seam gives way. Choosing thread is matching: the strand must pass cleanly through needle and fabric, hold its twist under the repeated pull of stitching, and bear the loads the seam will bear in wear and washing, without being so coarse that it damages the cloth it joins.

Thread and Yarn

The textile definition of thread points directly to yarn, and the two words name closely related things. Both are continuous strands made by spinning fibers together, and in general use yarn is the broader term for strands intended for weaving, knitting and other textile construction, while thread is the word most often used for the finer strand prepared for sewing. The distinction is one of customary use and intended purpose rather than of structure: a strand is judged as thread by the work it is wound, sold and threaded for. That is why sewing notions, bobbins and needlework supplies speak of thread, while weaving and knitting supplies speak of yarn, even though the spinning that produced both strands relied on the same principle of twisting many thin fibers into one.

The same word serves several other trades, and the shared idea is a long, thin line that connects or runs through. The helical blades of a screw are also called threads, and in hardware a thread is used to connect two things together, such as a screw to a piece of wood or two segments of a hose. In computer science, thread is short for thread of execution, and a string of consecutive message postings to a newsgroup, mailing list or other forum is also known as a thread. Each use borrows the textile image of a single line drawn out and followed from end to end. In the sewing room that line is literal and physical: fibers spun together into a strand strong enough to hold the pieces of a garment together for the life of the cloth.