This unique crochet hat is inspired by the Borromean rings, a mathematical structure where three interlocking circles create an inseparable yet non-directly-linked design. Perfect for intermediate crocheters, this pattern uses front post and back post single crochet stitches to create a ribbed texture, along with crab stitch edging for a polished finish. The result is a cozy, stylish beanie that’s fully customizable in size while maintaining its iconic interlocking structure (Source: Borromean Rings Hat Crochet Pattern).

Construction & Appearance:
The hat is constructed from three tubular crocheted circles, each worked in the round using worsted-weight yarn. The first two circles are crocheted separately, while the third is woven through them in an under-over sequence to achieve the Borromean interlock. Once complete, the circles form a snug, stretchy beanie with a distinctive layered look. Optional contrast edging adds a pop of color to the design.

Gauge & Sizing:

• Gauge: 4 stitches = 1 inch (critical for proper interlocking).
• Finished Measurements: Each circle measures 13” long × 3” wide; hat height is 9”. Fits head circumferences of 22–24” as written, but adjustments are provided for smaller (20–22”) or larger (24–26”) sizes.
• Hooks: Size K-10½ (6.50mm) for main body, I-9 (5.50mm) for edging.

Materials Needed:

• Yarn: 1 skein of worsted weight yarn (355 yards) in the main color; optional small amount of contrasting yarn for edging.
• Tools: Scissors, tapestry needle, stitch markers.

Number of Skeins/Yarn Info:
The pattern requires 1 skein of worsted weight yarn for the main color. If adding contrast edging, only a small amount of additional yarn is needed—perfect for using up scraps!

Stitch Diagrams/Charts:
This pattern does not include stitch diagrams or charts but provides detailed written instructions. A QR code links to a video guide for visual learners, particularly helpful for mastering techniques like weaving the third circle and working the crab stitch edging.

Care Instructions:
To care for your finished hat, gently hand wash in cool water with mild detergent, reshape, and lay flat to dry.

With its blend of math-inspired design and practical construction tips, this pattern is both a fun challenge and a rewarding project. Whether you’re making it for yourself or as a gift, the Borromean Rings Hat is sure to impress!