A blade or belt size is only a few numbers, but each one means something specific. This guide explains them, how to read the size printed on a label, and when BenchRefill counts a size as documented.
Belts: width and loop length.
A sanding belt has two dimensions. Width runs straight across the belt. Length is the whole loop measured along the belt, not just the part you see on the machine. Labels usually give the width first, as in 75 × 533 mm or 3 × 21 in. If you are not sure which figure is which, the larger one is the length.
The size isn’t everything. The backing, the joint, the abrasive and the grit also have to suit the machine and the job, and the manual may name a type.
Blades: length, width, thickness and teeth.
A bandsaw blade is usually described with four figures. JET lists the blade supplied with its JWBS-9 bandsaw as “59-1/2" x 1/4" x 0.013" - 6TPI”:
- 59-1/2" is the length of the whole loop: 59.5 in, or 1511.3 mm. This is the figure that has to match your machine.
- 1/4" is the width, from the back of the blade to the tooth tips. A machine takes a range of widths; the JWBS-9 takes 1/8 to 3/8 in.
- 0.013" is the thickness of the blade body, 0.33 mm.
- 6TPI means six teeth per inch, a choice for the material you cut. Choosing TPI explains it.
Width range and thickness.
Our machine pages show the width range the manufacturer documents. A narrower blade follows tighter curves and a wider one cuts straighter; blade width and curves has the charts. Thickness is documented less often, and where it is missing we show it as unknown. Thicker blades are stiffer and bend less easily round small wheels, so where the manual gives a thickness, stay with it.
Fractions and millimetres.
One inch is exactly 25.4 mm. Inch sizes are written with fractions, such as 93-1/2 in for 93.5 in. These are the fractions you will meet most often:
| Inches | Decimal | Millimetres |
|---|---|---|
| 1/16 | 0.0625 | 1.5875 mm |
| 1/8 | 0.125 | 3.175 mm |
| 3/16 | 0.1875 | 4.7625 mm |
| 1/4 | 0.25 | 6.35 mm |
| 5/16 | 0.3125 | 7.9375 mm |
| 3/8 | 0.375 | 9.525 mm |
| 1/2 | 0.5 | 12.7 mm |
| 5/8 | 0.625 | 15.875 mm |
| 3/4 | 0.75 | 19.05 mm |
| 7/8 | 0.875 | 22.225 mm |
The unit converter handles any size, including mixed fractions such as 44-7/8.
Nominal is not always exact.
Manufacturers often round an inch size to whole millimetres: a 48 in belt is 1219.2 mm but is usually printed as 1220 mm. We keep the notation the manufacturer used, show the exact conversion next to it, and never treat a rounded conversion as the same size. Metric and inch sizes explains what the difference means in practice.
What “Documented” means here.
A size is marked Documented only when a manufacturer source, such as a manual, data sheet or product page, states every dimension we need: width and length for a belt, length for a blade. Each machine page links that source and shows when we checked it. Anything a source doesn’t state stays unknown; we don’t fill gaps from similar models. How we source sizes has the details.