Thick thread is called heavy-duty, upholstery, topstitching, or jean thread, depending on its use, with specific strong types like Kevlar or heavy nylon for extreme durability, and identified by weight systems like Tex (higher number = thicker) or Denier (higher number = thicker).
Thick embroidery thread is defined by its increased weight, measured in tex or denier units, and enhanced fiber construction. These threads typically range from 40-weight to 12-weight, with lower numbers indicating thicker threads.
Heavy weight threads (12 – 30 wt)
Heavy weight threads are used when you need strong or decorative stitches. They are perfect for topstitching, decorative stitching, and working with heavy fabrics like denim or canvas.
Kevlar(TM) thread is one of the strongest and most fire retardant commercially available threads. It is about 2.5 times stronger than nylon or polyester, has almost no stretch, does not melt, and decomposes at 800F.
Twine is a strong thread, light string or cord composed of string in which two or more thinner strands are twisted, and then twisted together (plied). The strands are plied in the opposite direction to that of their twist, which adds torsional strength to the cord and keeps it from unravelling.
Most common threads
Fine threads are stronger in tension due to the increased contact area and smaller pitch. The smaller pitch of fine threads provides greater resistance to vibration-induced loosening. Fine threads are suitable for harder materials, as they allow for tighter engagement and stronger connections.
A string has a larger diameter than a thread. Usually string is made by twisting multiple threads together.
What Is a Coarse Thread Screw? Coarse thread fasteners have a wider thread pitch — the distance between each row of threading. Since this pitch is wider, coarse thread screws have a low number of threads across the distance of the fastener.
General purpose threads are about Tex 30, and the lighter weight of "upholstery thread" is often called V69, and is Tex 70. The even heavier weight upholstery thread is often called v96, and is Tex 100.
Cotton Perlé is available in four sizes (3, 5, 8 and 12) with size 3 being the thickest thread and size 12 the finest.
cord cotton fiber filament hair ribbon strand string wire wool yarn.
Class 3 threads are often specified for tight tolerance fastener applications in critical use situations where safety and strength are a primary concern, such as the aerospace industry.
Nylon Thread: Nylon thread is known for its exceptional strength, making it suitable for sewing projects that require high tensile strength. It is often used for heavy-duty applications such as upholstery, leatherworking, and outdoor gear construction.
In uk yarn is called wool.
E string: This is the thickest string. It is usually closest to you and is often called the 6th string. When played open (without pressing down any frets) it produces the Low E note.
Size for size, a fine thread is stronger than a coarse thread. This is both in tension (because of the larger stress area) and shear (because of their larger minor diameter). Because of the smaller pitch, they allow finer adjustments in applications that need such a feature.
polyester threads
While I don't often sew with polyester fabrics, polyester thread is usually a good choice. Polyester thread is smooth, strong, absolutely regular, and requires no special skills. It works in all home sewing machines.
The threading process produces many types of threads (there are more than 20 types), depending on the different parameters established, such as the position, shape, number of threads or the direction of the helix. Thus we have the general or common use threads (ISO metric, UNF…) and those for pipes (BSP, NPT…).
In this case, the 40 wt thread is slightly thicker (heavier) than the 50 wt thread. Note bene: you can tell at a glance which weight you're grabbing from your collection: 40 wt is always on a green spool while 50 wt is always on an orange one.
What is the 3-Thread Rule? The 3-thread rule ensures that a bolt or stud extends at least three full threads beyond the nut to guarantee full engagement. This prevents improper fastening, which could lead to loosening or joint failure.