Kevlar sewing thread

Para-Aramid fibers such as Alkex® & Kevlar®,  offer a multitude of properties that make them an excellent choice for various applications. Their exceptional strength-to-weight ratio and high break strength provides high tensile strength and modulus, making them ideal for applications requiring robust and durable materials. Para-aramid fibers are great solution for applications where the fiber will be under constant load or a high cycle count, taking advantage of low elongation and creep properties.

Para-aramid fibers exhibit excellent resistance to high temperatures, maintaining their mechanical properties even at elevated temperatures. This heat resistance makes them suitable for applications in thermal insulation and protective clothing. Additionally, para-aramid fibers demonstrate good chemical resistance, enabling them to withstand exposure to acids, alkalis, and many organic solvents without significant degradation. However, para-aramid fibers are known to have poor resistance to ultraviolet (UV) radiation, which can cause degradation and loss of strength over time. Therefore, they require proper protection and shielding from direct sunlight or prolonged exposure to UV radiation to maintain their performance and longevity.

Stronger than steel, para-aramid is a high tenacity, high modulus fiber that maintains its strength even after heat aging at elevated temperatures. It is specifically developed to meet the stringent fire and heat safety standards required in industries such as aerospace, automotive, and insulation, making it an excellent choice for safety products and protective garments. Additionally, it is used in military applications and for tape edging operations on mattresses.


 Composition: 100% para-aramid continuous twisted filament yarn

 Specification: 200D/2, 200D/3, 400D/2, 400D/3 1000D/2, 1000D/3, 1500D/2, 1500D/3, 3000D/2, 3000D/3


Color: yellow, black

Kevlar/Chinese brand para aramid

We can tailor make any bobbin size per requirement.

Features & Benefits

  • High Strength-Stronger than steel, para-aramid is a high tenacity, high modulus fibre and delivers high retained strength after heat ageing at elevated temperatures
  • Decomposition-Para-aramid starts to decompose (turn to ash) at approximately 800°F (426°C), withstanding much higher temperatures than nylon or polyester. PTFE-coated fiberglass offers even greater heat resistance, operating at temperatures up to 1022°F (550°C). For perspective, a disposable butane lighter burns at around 3578°F (1970°C). 
  • Melting – para aramid does not melt. This is essential in fire retardant gear.
  • Stretch – Kevlar thread stretches approximately 2% before breaking. For instance, a 100-foot piece of Kevlar would extend to 102 feet just before it breaks. When used to sew stretchy fabrics, Kevlar can cause the seams to pucker.
  • Acids and Alkalis – Kevlar thread has good resistance to dilute acids and bases. It is degraded by strong mineral acids and to lesser extent, by strong mineral bases. This is important when Kevlar thread is used in a laboratory setting.
  • Bleaching and Solvents – Kevlar thread should not be bleached. It has excellent solvent resistance. This matters when Kevlar gear is reused.
  • Mildew and Aging – Kevlar/Chinese brand para aramid thread has excellent resistance to mildew and aging.
  • UV Resistance – UV rays cause Kevlar to fade more quickly than many other thread types, and prolonged exposure to sunlight or even bright interior lighting can lead to deterioration. Therefore, it is recommended to store Kevlar thread in a dark place.
  • Abrasion – Kevlar thread has good abrasion resistance.


  • Bonded and Soft – “Bonded” refers to thread that has a coating, which reduces heat at the needle tip and prevents unraveling. “Soft” means the thread lacks this coating
  • Machine Sewing – Use bonded thread for sizes 69 and higher; for thinner threads, bonding typically isn’t necessary. Bonding can interfere with adhesives. It can be removed by soaking the thread in alcohol, but this may compromise its strength and heat resistance.
  • Hand Sewing and Hanging – Whether the thread is soft or bonded does not matter
  • Monocord – “Monocord” refers to thread made from a single ply with a bonded coating, giving it a flat, ribbon-like shape suitable for double-needle machines. Some of our lighter weight threads use this construction. When machine sewing with monocord, a tensioning adjustment is often necessary
  • S- Twist / Z- Twist Loose Twist / No Twist / and Yarn
  • Kevlar Thread Spool Sizes
    We sell most of our Kevlar/Chinese brand para aramid filament thread in small spool (100gram/200gram) as twisted filament are very smooth and in order to keep it stable we need it big bottom size. Any size can be tailor made per buyer requirement.


Para aramid  will degrade with prolonged UV light exposure. These fibers will brown and weaken over time.  Please keep this fiber stored away in a dark room and in the UV protective bag the fiber was shipped in.

Para aramid fiber will absorb atmospheric moisture up to 5-7% in weight. This fiber should be stored in a cool, dry room with low humidity. A desiccant bag was included with this fiber to prevent regain during transit and short-term storage at your facility.

Acid: Prolonged exposure to concentrated strong acids will cause degradation
Alkali: Degrades with prolonged exposure to Sodium Hypochlorite
Organic Solvent: Moderate degradation in Carbon Tetrachloride and Ethylene Glycol