Label the Parts of a Windmill – Worksheet With a Key

All 15 parts on the diagram

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Start here: 7 main parts 7

Sails The frames that catch the wind and turn the windshaft.
Cap The top of the mill, which turns the sails into the wind.
Tower The fixed body of the mill, built of brick or stone.
Fantail A small wheel behind the cap that turns it into the wind.
Windshaft The axle turned by the sails; it carries the brake wheel.
Brake wheel The big gear on the windshaft; a brake grips its rim.
Runner stone The upper millstone, which turns.

The mill from outside 2

Stage A platform round the tower, from which the miller tends the sails.
Stocks The long timbers, fixed through the windshaft, that carry the sails.

The mill cut through 6

Wallower The gear atop the upright shaft, driven by the brake wheel.
Upright shaft The tall shaft down the middle, carrying the drive to the stones.
Great spur wheel The wide gear on the upright shaft that drives the stone nuts.
Stone nut A small gear that drives one pair of stones.
Bedstone The lower millstone, which stays still.
Hopper A funnel above the stones that feeds the grain to them.

How this list was compiled: Read 2026-09-30; a name is kept only where two of these use it. (1) Wikipedia, Windmill (the horizontal windshaft carries the sails; the brake wheel is fitted on the windshaft and has the brake round its rim; it drives the wallower at the top of the vertical upright shaft; the great spur wheel, lower on the upright shaft, turns one stone nut or more on the shaft of each millstone; the cap), Tower mill (a brick or stone tower with a cap that rotates to bring the sails into the wind; stock; gallery), Windmill fantail (a small rear windmill at right angles to the sails, which turns the cap automatically) and Windmill sail. (2) R. J. Brown, Windmills of England (1976), https://archive.org/details/windmillsofengla0000brow , read as passages through the Internet Archive's full-text search: fantail, windshaft, brake wheel (the largest gear), wallower, upright shaft, great spur wheel, stone nuts, stocks (two heavier timbers set at right angles through the windshaft), whips, the curb the cap turns on, the stage from which the miller adjusts the sails, hopper; millstones were in pairs, only the upper runner stone revolved and the lower bed stone was stationary. (3) John Vince, Discovering Windmills, https://archive.org/details/discoveringwindm0000vinc , read the same way: its gear diagrams list windshaft, brake wheel, wallower, vertical shaft, great spur wheel, stone nut, hopper, runnerstone and bedstone; fantail, cap, curb, stage and gallery in its text. (4) F. H. Shelton, Windmills, Picturesque and Historic (1919), https://archive.org/details/windmillspicture00shel : sails or sweeps, the great shaft and great wheel, the pinion or lantern or trundle or wallower wheel on a vertical shaft, mill stones, the cap, tower mills. (5) Peter Barlow's description quoted in Brangwyn and Preston, Windmills (1923), https://archive.org/details/windmills_202003 (wind shaft, whips, brake-wheel and its brake), and Knight's American Mechanical Dictionary (1882), https://archive.org/details/knightsamericanm03knig (sails, whips, the windmill-cap, upright shaft). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. A schematic, not to scale. Licence: own work

How it works

To label the parts of a windmill, write a name on the line for each number. Numbers 1 to 6 are on the mill from outside, 7 to 15 on the mill cut through to its gears and stones.

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Windmill worksheet word bank

In alphabetical order, to copy onto the board: bedstone, brake wheel, cap, fantail, great spur wheel, hopper, runner stone, sails, stage, stocks, stone nut, tower, upright shaft, wallower, windshaft.

Numbers that get swapped

Outside, 1 is a lattice frame (sails) and 6 the bar it is fixed to (stocks). Inside, four wheels run from the top down: 8 the upright one, seen edge-on (brake wheel), 9 the flat one under it (wallower), 11 the wide one below (great spur wheel) and 12 the small one at its end (stone nut). 7 is the sloping bar (windshaft), 10 the post down the middle (upright shaft). 13 is the upper slab (runner stone), 14 the lower (bedstone).

When marking, sweeps is right on line 1, gallery on line 5 and vertical shaft on line 10.
Two stone nuts are drawn, one at each end of the wide wheel. Number 12 covers both.

Questions and answers

What are the main types of windmill?

Post mills, tower mills and smock mills. The whole body of a post mill turns on one post. On a tower mill of brick or stone, only the cap turns. A smock mill has a wooden frame in place of the masonry.

How many sails does a windmill have?

Most have four. Five-, six- and eight-sail mills were built too, in Great Britain and Germany above all. A mill with an even number can keep working after one sail is damaged, once that sail and the one opposite are taken off.

What does the brake wheel do in a windmill?

Two jobs. Teeth in the side of its rim drive the wallower, which sends the turning down the upright shaft. And the brake runs around the outside of the same rim.

Does the windmill worksheet have an answer key?

Yes. The answer key prints both drawings with the fifteen names on their numbered lines, from sails to hopper.