Thread (yarn)

Last updated
An assortment of different colors of thread SpoolsOfThread.jpg
An assortment of different colors of thread
Multi-colored stranded embroidery floss Embroidery Floss Multi-Colored 10-21-09 IMG 8048.jpg
Multi-colored stranded embroidery floss

Thread is a type of yarn but similarly used for sewing. It can be made of many different materials including cotton, wool, linen, nylon, and silk.



Thread is made from a wide variety of materials. Where a thread is stronger than the material that it is being used to join, if seams are placed under strain the material may tear before the thread breaks. Garments are usually sewn with threads of lesser strength than the fabric so that if stressed the seam will break before the garment. Heavy goods that must withstand considerable stresses such as upholstery, car seating, tarpaulins, tents, and saddlery require very strong threads. Attempting repairs with light weight thread will usually result in rapid failure, though again, using a thread that is stronger than the material being sewn can end up causing rips in that material before the thread itself gives way.

Thread material
Cotton Spun traditional threadgeneral
Cotton/polyester A cotton thread with a polyester core which is slightly stretchy but retains the traditional look of cottonstrength without sheen
FusibleFuses sewn fabrics together when ironed binding and appliqué
Linen A spun thread, typically in a thicker gauge than that used for fabric garments. It may be waxed for durability and resistance to mildew.Traditional leather saddlery; leather luggage, handbags, and accessories; and beadwork.
MetallicsA delicate metallic coating protected by an outer coating providing extremely vibrant color/glitter and/or texture.decoration
Nylon A transparent monofillament which can be melted by an iron. Nylon is usually stronger than polyester.strength with transparency
PolyesterA synthetic blend which is stronger and stretchier than cotton with little or no lint (may be texturized)strength
Rayon Made from cellulose, but not considered to be a natural fibre because it is highly processed. Useful for obtaining bright colors, though not always color-fast.high sheen, soft texture
Silk A very fine, strong and hard-to-see thread; tends to degrade over time, however.high strength and often high sheen, used for attaching beads
Wool A thicker thread. homespun look, rougher texture, highly insulating, water absorbent
Water-soluble Dissolves when washedtemporary basting


Polyester/polyester core spun thread is made by wrapping staple polyester around a continuous polyester filament during spinning and plying these yarns into a sewing thread. Core Spun Thread

Measurement types and labeling

Thread gauges

Yarns are measured by the density of the yarn, which is described by various units of textile measurement relating to a standardized length per weight. These units do not directly correspond to thread diameter.

Weight (Wt.) and Gunze count

The most common weight system for thread specifies the length of the thread in kilometres required to weigh 1 kilogram. Therefore, a greater weight number (indicated in the American standard by the abbreviation wt) indicates a thinner, finer thread. The American standard of thread weight was adopted from the Gunze Count standard of Japan, which uses two numbers separated by a forward slash. The first number corresponds to the wt number of the thread and the second number indicates how many strands of fiber were used to compose the finished thread. It is common to wrap three strands of the same weight to make one thread, though this is not a formal requirement in the US standard (which is therefore less informative).

Thread Weight Table
WeightGunze CountCommon Use [2]
Light60 wt#60/3bobbin or appliqué
Thin50 wt#50/3bobbin or appliqué
Regular40 wt#40/3Quilting
Upholstery30 wt#30/3Decorative
Heavy20 wt#20/3Decorative


A denier weight specification states how many grams 9,000 metres of the thread weighs. Unlike the common thread weight system, the greater the denier number, the thicker the thread. The denier weight system, like the common weight system, also specifies the number of strands of the specified weight which were wrapped together to make the finished thread. Only embroidery threads have their weights given in denier.


Tex is the mass in grams of 1,000 metres of thread. If 1,000 m weighs 25 g, it is a tex 25. Larger tex numbers are heavier threads. Tex is used throughout North America and Europe.

Silk machine twist

Manufacturers producing fine silk threads, apply their own scales of thread measurement using "aughts" or zeroes at the finest end and FFF at the other, thus scaling 000, 00, 0, A, B, C, D, E, F, FF, FFF. The three finest threads are described as having "three aughts", "two aughts", and "one aught" respectively, and as having different "aught counts". Within a given manufacturer's spectrum, a higher "aught count" indicates a finer thread: this may be given as a single digit followed by a forward slash and a zero— for example, 3/0 indicates a three-aught thread or a thread size "000", but this number only has significance when compared to other threads produced by the same manufacturer: one manufacturer's 3/0 will always be more fine than that same manufacturer's 2/0, but may not be comparable to the 3/0 of another manufacturer. Very roughly, however, size A is 900 yards per pound of thread, and every 100 yards difference is one letter size different. The size is always given for the overall thread, not its individual silk plies.


Some heavier duty threads are given "commercial" size designations in set sizes of 30, 46, 69, 92, 138, 207, 277, 346, 415 and 554 only. Each of these numbers is merely the thread's denier size divided by 10. A commercial size 138 thread has a denier of 1380.

Conversion information

Thread weight conversion table

Converting FromConverting ToMethod
WeightDenier9000 / weight
WeightTex1000 / weight
DenierWeight9000 / Denier
DenierTexDenier / 9
TexDenierTex x 9
TexWeight1000 / Tex
CommercialDenierCommercial x 10
DenierCommercialDenier / 10
CommercialTexCommercial / 9 x 10
TexCommercialTex / 10 x 9

For example: 40 weight = 225 denier = tex 25 = [theoretical] commercial 27.8 . A common tex number for general sewing thread is tex 25 or tex 30. A slightly heavier silk buttonhole thread suitable for bartacking, small leather items, and decorative seams might be tex 40. A strong, durable upholstery thread, tex 75. A heavy-duty topstitching thread for coats, bags, and shoes, tex 100. A very strong topstitching thread suitable for luggage and tarpaulins, tex 265–tex 290. But a fine serging thread is only tex 13. And blindstitching and felling machines, an even finer tex 8.


Threads of different composition and construction may be labeled in a variety of ways. Most threads are composed of 2 or more "plies" of fiber, and this information is often provided on thread packaging along with the finalized thread's weight, according to a particular scale of measurement. The actual physical diameter of a thread is not recorded and is unhelpful.

Spools may have codes that indicate their fiber content as well such a "P" for polyester. If a fiber content is given in the label code, it will be the first piece if information located there.


120D/2Spool is 120 denier thread composed of 2 plies (each of 60 denier)
50S/3Spool has a weight of 50 and is composed of 3 plies whose individual weights are not indicated
P60/3This is a spool of polyester thread of weight 60 and is made up of 3 plies
Den 75/2Spool of 75 denier thread made of 2 plies
#60/2This is the spool's Gunze count: the spool has thread of 2 plies of 60 weight thread each

Sometimes a manufacturer does not provide any weight specification at all on its spools and instead provides only the fiber content and spool length such as "100% Silk 250 m". This means only that the spool has 250 meters of pure silk, but does not indicate how many plies make up that thread nor what the plies' or the combined thread's weight is.

Cotton count

The cotton count system is based on the number of 840 yard hanks that will result from a single pound of a particular finished thread. This is the non-metric equivalent of the Gunze count, and is given with two numbers separated by a slash: the first is the size of the thread and the second is the number of plies of that size used in the finished thread. The cotton count was developed for the cotton industry, but cotton counts are also frequently given for polyester and polyester/ cotton blends as well.

Hong Kong ticket

A Hong Kong ticket number, when present, is a cotton count number without the slash and with the final number always indicating the number of plies if more than one. A Hong Kong ticket number of 1002 is made of two plies of size 100 thread; a number of 100 is made of a single ply of size 100 thread; a size 503 is made of three plies of size 50 thread.

Single's equivalent

A spool of thread may be described in terms of its "single's equivalent". This is the cotton count size of the thread divided by the number of plies which make it up. A spool of 30/3 thread has a single's equivalent of 10, because a single strand or ply of that thread has a cotton count size of 10. A 20/2 spool has the same single's equivalent as a 30/3, but a 30/2 spool has a single's equivalent of 15, which means it is composed of individually heavier plies than a 30/3.

High-temperature sewing threads

High temperature sewing threads provide durability and resistance to extreme temperatures. Some threads can be used for applications up to 800 °C (1472 °F). There are a variety of different sewing threads available which have different applications and benefits.

Kevlar-coated stainless steel sewing threads have a high-temperature and flame-resistant steel core combined with Kevlar coating designed to facilitate easier machine sewing. The stainless steel core has a temperature resistance of up to 800 °C (1472 °F) and the Kevlar coating is heat-resistant up to 220 °C (428 °F).

PTFE coated glass sewing threads have an excellent temperature resistance combined with a PTFE coating to provide easier machine sewing. The glass core has a temperature resistance of up to 550 °C (1022 °F) and the PTFE coating is heat-resistant up to 230 °C (446 °F).

Nomex sewing threads are inherently flame-retardant and heat-resistant with a tough protective coating that resists abrasion during the sewing operation. It is temperature resistant up to 370 °C (698 °F).

Bonded nylon sewing threads are tough, coated with abrasion resistance, rot proofing, and have good tensile strength for lower temperature applications. They are temperature-resistant up to 120 °C (248 °F).

Bonded polyester sewing threads are tough, coated with abrasion resistance, rot proofing, and have exceptional tensile strength for lower temperatures but heavier-duty sewing operations. They are temperature-resistant up to 120 °C (248 °F).

See also


  1. "Thread Tips - Threads for Quilters". 2011-10-16. Retrieved 2011-11-30.
  2. "How to choose the right thread for your project and your sewing machine". Retrieved 2019-11-30.

Related Research Articles

<span class="mw-page-title-main">Crochet</span> Technique of creating lace or fabric from thread using a hook

Crochet is a process of creating textiles by using a crochet hook to interlock loops of yarn, thread, or strands of other materials. The name is derived from the French term crochet, meaning 'small hook'. Hooks can be made from a variety of materials, such as metal, wood, bamboo, or plastic. The key difference between crochet and knitting, beyond the implements used for their production, is that each stitch in crochet is completed before the next one is begun, while knitting keeps many stitches open at a time. Some variant forms of crochet, such as Tunisian crochet and broomstick lace, do keep multiple crochet stitches open at a time.

<span class="mw-page-title-main">Yarn</span> Long continuous length of interlocked fibres

Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery, or ropemaking. It can be made of a number of natural or synthetic materials, and comes in a variety of colors and thicknesses. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework.

<span class="mw-page-title-main">Fiber</span> Natural or synthetic substance made of long, thin filaments

Fiber or fibre is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.

<span class="mw-page-title-main">Fire hose</span> Flexible tube used for delivering water or foam at high pressure, to fight fires

A fire hose is a high-pressure hose that carries water or other fire retardant to a fire to extinguish it. Outdoors, it attaches either to a fire engine, fire hydrant, or a portable fire pump. Indoors, it can permanently attach to a building's standpipe or plumbing system.

<span class="mw-page-title-main">Bedding</span> Bed covering fabrics

Bedding, also known as bedclothes or bed linen, is the materials laid above the mattress of a bed for hygiene, warmth, protection of the mattress, and decorative effect. Bedding is the removable and washable portion of a human sleeping environment. Multiple sets of bedding for each bed are often washed in rotation and/or changed seasonally to improve sleep comfort at varying room temperatures. Most standardized measurements for bedding are rectangular, but there are also some square-shaped sizes, which allows the user to put on bedding without having to consider its lengthwise orientation.

<span class="mw-page-title-main">Bed sheet</span> Rectangular piece of cloth or linen cotton used to cover a mattress

A bed sheet is a rectangular piece of cloth used either singly or in a pair as bedding, which is larger in length and width than a mattress, and which is placed immediately above a mattress or bed, but below blankets and other bedding. A bottom sheet is laid above the mattress, and may be either a flat sheet or a fitted sheet. A top sheet, in the many countries where they are used, is a flat sheet, which is placed above a bottom sheet and below other bedding.

<span class="mw-page-title-main">Fly tying</span> Process of producing artificial flies used in fly fishing

Fly tying is the process of producing an artificial fly used by fly fishing anglers to catch fish. Fly tying is a manual process done by a single individual using hand tools and a variety of natural and manmade materials that are attached to a hook. Although the recent history of fly tying dates from the middle 1800s, fly tyers were engaged in tying flys since at least 200 AD.

<span class="mw-page-title-main">Metallic fiber</span> Thread wholly or partly made from metal

Metallic fibers are manufactured fibers composed of metal, metallic alloys, plastic-coated metal, metal-coated plastic, or a core completely covered by metal.

<span class="mw-page-title-main">Textile manufacturing</span> The industry which produces textiles

Textile manufacturing is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful goods such as clothing, household items, upholstery and various industrial products. Overall, many things can be made with cotton, not just clothing.

<span class="mw-page-title-main">Sailcloth</span> Strong fabric of the type used to make ships sails

Sailcloth encompasses a wide variety of materials that span those from natural fibers, such as flax, hemp or cotton in various forms of sail canvas, to synthetic fibers, including nylon, polyester, aramids, and carbon fibers in a variety of woven, spun and molded textiles.

<span class="mw-page-title-main">Polyester</span> Category of polymers, in which the monomers are joined together by ester links.

Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

Vinyl coated polyester is a material frequently used for flexible fabric structures. It is made up of a polyester scrim, a bonding or adhesive agent, and an exterior PVC coating. The scrim supports the coating and provides the tensile strength, elongation, tear strength, and dimensional stability of the resulting fabric. Depending on its formula, the PVC coating makes the material waterproof and resistant to dirt, mildew, oil, salt, chemicals and UV rays and gives the material added strength and durability. It can be sewn or heat sealed by way of RF(Radio Frequency) welding or hot-air welding.

The manufacture of textiles is one of the oldest of human technologies. To make textiles, the first requirement is a source of fiber from which a yarn can be made, primarily by spinning. The yarn is processed by knitting or weaving, which turns yarn into cloth. The machine used for weaving is the loom. For decoration, the process of colouring yarn or the finished material is dyeing. For more information of the various steps, see textile manufacturing.

<span class="mw-page-title-main">Units of textile measurement</span> Systems for measuring textiles

Textile fibers, threads, yarns and fabrics are measured in a multiplicity of units.

<span class="mw-page-title-main">Novelty yarns</span> Any yarn with special effects introduced in spinning or plying

Novelty yarns include a wide variety of yarns made with unusual features, structure or fiber composition such as slubs, inclusions, metallic or synthetic fibers, laddering and varying thickness introduced during production. Some linens, wools to be woven into tweed, and the uneven filaments of some types of silk are allowed to retain their normal irregularities, producing the characteristic uneven surface of the finished fabric. Man-made fibres, which can be modified during production, are especially adaptable for special effects such as crimping and texturizing.

<span class="mw-page-title-main">Embroidery thread</span> Any of several types of thread designed for use in embroidery and related crafts

Embroidery thread is yarn that is manufactured or hand-spun specifically for embroidery and other forms of needlework.

Crochet thread

Crochet thread is specially formulated thread usually made from mercerized cotton for crafting decorative crochet items such as doilies or filet crochet. Crochet thread produces fabric of fine gauge that may be stiffened with starch.

<span class="mw-page-title-main">Ripstop</span>

Ripstop fabrics are woven fabrics, often made of nylon, using a reinforcing technique that makes them more resistant to tearing and ripping. During weaving, stronger reinforcement yarns are interwoven at regular intervals in a crosshatch pattern. The intervals are typically 5 to 8 millimeters. Thin and lightweight ripstop fabrics have a 2-dimensional structure due to the thicker yarns being interwoven in thinner cloth. Older lightweight ripstop fabrics display the thicker interlocking thread patterns in the material quite prominently, but more modern weaving techniques make the ripstop threads less obvious. A similar effect can be achieved by weaving two or three fine yarns together at smaller intervals.

A fabric structure is a structure made of fabric, with or without a structural frame. The technology provides end users a variety of aesthetic free-form building designs. Custom-made structures are engineered and fabricated to meet worldwide structural, flame retardant, weather-resistant, and natural force requirements. Fabric structures are considered a sub-category of tensile structure.

<span class="mw-page-title-main">Finishing (textiles)</span> Manufacturing process

In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finish textile or clothing. The precise meaning depends on context.