Loom Shafts Explained: What a Shaft Does and How Many You Need

Guide · Updated 22 October 2026

The order the ends are put on the shafts is the threading, and it has a guide of its own. This one is about the frames: what they do, why their number matters, and what a mill means when it asks how many shafts your design needs.

What a shaft is

To weave, the loom opens a gap between the warp threads, the shed. Some ends go up, the rest stay down, and the weft is passed through between them. Each warp end passes through the eye of one heddle (Turkish: gücü), a wire or cord hanging on a shaft. When a shaft is lifted, every end on it is lifted with it.

That is the whole job, and it is also the limit. A shaft cannot lift some of its ends and not others. Every end on one shaft always moves with the others. So the number of shafts is the number of independent groups the warp can be split into, and every pick of the cloth has to be made from those groups.

How many shafts a structure needs

A structure needs one shaft for every group of ends that lift the same way on every pick of its repeat. Ends that always move together can share a shaft. Ends that differ on even one pick need separate shafts. Applied to the common structures:

The figures for the first five are what our software works out from each structure's drawdown. Two things in the table surprise people. A basket needs no more shafts than plain weave, and a herringbone no more than a twill. In both cases the extra effect comes from how the ends are distributed on the shafts, not from extra shafts. Satin is the exception that sets the ceiling: the long floats that give it its sheen need at least five groups, which is why it is missing from a four-shaft loom.

Four, eight, sixteen, twenty-four

Looms are built with a fixed number of shafts, and the usual sizes go up in steps:

• 4 shafts: the common hand loom. It weaves plain, basket, every twill above and herringbone. Most tartans and checks fit here.
• 8 shafts: room for 8-end satin, more elaborate twills, and two structures side by side.
• 16 and 24 shafts: usually a dobby loom (Turkish: armürlü tezgâh). Shirting stripes with a woven texture, small all-over figures, and cloths that change structure from stripe to stripe.

On a hand loom, treadles lift the shafts and the tie-up says which shafts each treadle lifts. A dobby replaces the tie-up and treadles with a lift plan, a list of which shafts rise on each pick. That frees it from the handful of treadles a weaver's feet can reach, but it is still limited by its shafts.

Block weaves: where the shaft count climbs

Put two structures next to each other in one warp, for example a band of 2/2 twill beside a band of plain weave. The twill ends need their four shafts. The plain ends lift on a pattern the twill ends never use, so they cannot share those shafts and need two of their own. Working it out gives a threading of 1 2 3 4 1 2 3 4 5 6 5 6: six shafts, so this cloth needs an 8-shaft loom even though each half on its own would weave on four.

That is the usual surprise when a design reaches a mill. Each block of a different structure adds the groups it needs, and a few bands can push a design past what the loom on the other end has. Our designer works this out for you: when you open the export sheet, it reports how many shafts and treadles the cloth needs and whether that fits a 4, 8, 16 or 24-shaft loom, and it warns you when it does not.

Jacquard: no shafts at all

A jacquard loom (Turkish: jakar) takes the idea to its end. It has no shafts. Every warp end has its own hook and can be lifted on its own. Nothing has to move in groups, so the cloth can carry any figure: damask, brocade, a woven photograph. The trade is cost and set-up. For a check, a stripe or a twill, shafts do the job, and a dobby or a hand loom will weave it for a fraction of the cost.

What to tell a mill

• The structure, by name or as a draft, and the twill direction if there is one. See weave structures.
• The shaft count it needs, so they can say at once whether their looms take it.
• The full draft if the cloth changes structure across the warp, best as a WIF file. It carries the threading, tie-up and treadling together, and any weaving program can open it.

Frequently asked questions

What is a shaft on a loom?

A frame holding a row of heddles. Each warp end is threaded through one heddle, and lifting the shaft lifts every end on it at once. The number of shafts is the number of independent groups the warp can be lifted in.

Is a shaft the same as a harness?

Yes. Shaft is the usual word in British and most hand-weaving writing, and harness is common in American usage. Both mean the frame that carries the heddles.

What does çerçeve mean in weaving?

Çerçeve is the Turkish weaving word for a shaft, literally "frame". A mill asking for the çerçeve sayısı wants the shaft count. The heddles on it are the gücü, and the order the ends are put on the shafts is the tahar, the threading.

How many shafts do I need for twill?

Three for a 2/1 twill and four for 2/2 or 3/1. A herringbone needs the same four as the twill, because the reversal comes from the threading rather than from more shafts.

Why can't a four-shaft loom weave satin?

Satin ties each end down on a different pick so that no diagonal forms, and with only four groups there are not enough distinct positions for that. The smallest satin, the 5-end, needs five shafts.

What is the difference between a dobby and a jacquard loom?

A dobby still lifts the warp in shafts, often 16 to 24 of them, following a lift plan instead of treadles. A jacquard has no shafts and lifts every warp end individually, so it can weave any figure, at a much higher cost to set up.