gauge

In textiles, gauge is the count of stitches per unit length along the courses (rows) of a knitted fabric. It is measured most often in stitches per inch (SPI) in imperial systems or stitches per centimetre (SPC) in metric. A 15-gauge fabric has 15 stitches across one inch of finished width; a 28-gauge has 28. This single number governs fabric weight, drape, texture, and production speed more than almost any other variable.

Gauge is inherent to the machine, not a setting the operator adjusts mid-run. A knitting machine is built with a specific needle spacing, usually expressed as the gauge number itself. Fine-gauge machines (24 gauge and higher) produce dense, smooth fabric and require finer yarn; coarse-gauge machines (7 to 12 gauge) work with heavier yarns and run faster. Industrial circular and flatbed machines come in fixed gauge sizes. Changing gauge means changing machines, not adjusting a dial.

Gauge and yarn relationship

The relationship between machine gauge and yarn count is not arbitrary: a 12-gauge machine expects yarn around 2 to 4 ply (in worsted weight terms), while a 28-gauge machine works with singles or 2-ply fine yarns. Running yarn too heavy for the gauge causes loops to pile up and jam; too fine yarn produces baggy, uneven stitches. The mill specifies a working range for each gauge and enforces it through yarn procurement and quality control.

Confusion sometimes arises because 'gauge' also refers to the looseness or tightness of knitting itself, controlled by tension settings and needle depth. This is different from the machine gauge. A 15-gauge machine running at tight tension still produces denser fabric than a 12-gauge running loose, but both fabrics differ fundamentally in stitch count per inch, which is the true gauge.

Mills record final fabric gauge when spec'ing products because it determines suitability for end use. A T-shirt jersey typically runs 20 to 24 gauge; hosiery may be 168 gauge or higher (referring to the number of needles on a single-feed circular machine). The gauge appears on shade cards, inspection logs, and customer specifications as a control point that prevents the wrong fabric from reaching finishing or shipment.