Traditional / Public Domain — a popular variation of the classic Pinwheel block
An energetic block featuring two interlocking pinwheel motifs created by combining half-square triangles in a specific rotation. The overlapping pinwheels create a sense of depth and movement that is surprisingly easy to achieve with basic half-square triangle units.
The Double Pinwheel is a natural evolution of the simple Pinwheel block, dating to the mid-1800s. While the basic Pinwheel uses four half-square triangles, the Double Pinwheel typically uses eight or sixteen, arranged to create two overlapping spinning motifs. It was a popular block for teaching more advanced HST arrangements while still using only basic piecing.
Pinwheel patterns have been popular across cultures, echoing the windmills, weather vanes, and children's pinwheel toys that were familiar objects in rural life. The Double Pinwheel added sophistication to an already beloved motif. During the late 1800s and early 1900s, the pattern was frequently featured in farm journals and ladies' magazines as an intermediate step between the simple Pinwheel and more complex spinning designs like Kaleidoscope blocks.
Also known as: Double Windmill, Whirligig, Twin Pinwheels, Double Flutter
finished Block Size
12"
seam Allowance
1/4"
grid Basis
4x4 grid of half-square triangle units (each finishes to 3")
units Required
16 half-square triangle units
All measurements include 1/4" seam allowance unless noted.
| Piece | Fabric | Cut Size | Qty | Notes |
|---|---|---|---|---|
| HST Square | Color A | 4 1/4" x 4 1/4" | 4 | Pair with background for 8 HSTs |
| HST Square | Color B | 4 1/4" x 4 1/4" | 4 | Pair with background for 8 HSTs |
| HST Square | Background | 4 1/4" x 4 1/4" | 8 | Half pair with Color A, half with Color B |
Draw a diagonal line on the wrong side of each 4 1/4" background square. Pair 4 background squares with 4 Color A squares and 4 background squares with 4 Color B squares. Sew 1/4" on each side of the line. Cut on the line. Press toward the colored fabric. You will have 8 HSTs of Color A and 8 HSTs of Color B (16 total).
Tip: Trim all HSTs to exactly 3 1/2" square before arranging the block.
Layout 16 HSTs in a 4x4 grid. Create two interlocking pinwheels: Color A HSTs form one pinwheel spinning clockwise in the upper-left area, while Color B HSTs form a second pinwheel spinning counterclockwise in the lower-right area. The two pinwheels share the center four positions.
Sew the four HSTs in each row together with 1/4" seams, right sides together. Press seams in alternating directions between rows: Row 1 to the left, Row 2 to the right, Row 3 to the left, Row 4 to the right.
Nest seams at each intersection and pin. Sew the four rows together with 1/4" seams. Press row-joining seams in one direction.
Tip: Pin at every seam intersection — there are many points to match in this block.
Press the completed block from the front. It should measure 12 1/2" square. Both pinwheel motifs should be clearly visible, spinning in their respective directions. Trim if needed.
See how this traditional pattern looks in different color combinations.
Straight set — pinwheels create continuous spinning patterns across the quilt
With sashing to isolate each double pinwheel
Alternating with plain blocks for breathing room between the busy blocks