by wefalck » Wed Mar 04, 2026 6:18 am
If it's multifilament stranded material, i.e. twisted like rope, its diameter is not very well defined. Its actual diamter depends on how much it was twisted when measured. This is why the thread and fabric industry came up with denier and similar weight and length-based measures.
1 denier is the weight in grams of 9000 metres of the thread in question. As the specific density of different fibre materials is different, for the same denier fibres of different materials will have different diameters. Lycra has a density of 1.21 to 1.35 g/cm^3, Nylon of 1.15 g/cm^3, polyester of 1.3 to 1.4 g/cm^3, and cotton of around 1.55 g/cm^3.
So, if my calculations are correct and assuming that it were a monofilament, a 110 denier Lycra thread should have a diameter of around 0.12 mm, while the diameter of the same 110 denier cotton fibre would have an approximate diameter of only 0.10 mm. In reality the effective thread diameters would be somewhat larger, as the thread is made up of three to four strands with airspace in the 'keeps'.
Established thread brands, such as Alterfil or Gütermann offer threads down to 2.5 tex = 23 den = 0.05 mm diameter.
I made myself an MS Excel spreadsheet for calculating the approximate diameters of various commercially available threads.
If it's multifilament stranded material, i.e. twisted like rope, its diameter is not very well defined. Its actual diamter depends on how much it was twisted when measured. This is why the thread and fabric industry came up with denier and similar weight and length-based measures.
1 denier is the weight in grams of 9000 metres of the thread in question. As the specific density of different fibre materials is different, for the same denier fibres of different materials will have different diameters. Lycra has a density of 1.21 to 1.35 g/cm^3, Nylon of 1.15 g/cm^3, polyester of 1.3 to 1.4 g/cm^3, and cotton of around 1.55 g/cm^3.
So, if my calculations are correct and assuming that it were a monofilament, a 110 denier Lycra thread should have a diameter of around 0.12 mm, while the diameter of the same 110 denier cotton fibre would have an approximate diameter of only 0.10 mm. In reality the effective thread diameters would be somewhat larger, as the thread is made up of three to four strands with airspace in the 'keeps'.
Established thread brands, such as Alterfil or Gütermann offer threads down to 2.5 tex = 23 den = 0.05 mm diameter.
I made myself an MS Excel spreadsheet for calculating the approximate diameters of various commercially available threads.