How to Do a Single Crochet Tube Spiral. The French began this needle art during the 18th century. Learning to crochet a tube-shaped or cylindrical spirals is useful in projects like sweater arms, socks, and hats. Tube-shaped spirals are simple to work and, unlike common stacked tubes, turn out seamless.
Chain the length required for your project. Join the chain and form a ring by inserting the hook through both loops of the first stitch and making a slip stitch. If possible, measure or check the size of your tube before continuing.
Mark the end of the last round or start of the new round, if you are tracking rounds. Form round 2 by working one single crochet (sc) in each stitch in the chain.
Complete the round. Create round 3 of the tube spiral by working one single crochet in each stitch you made round 2.
Continue working the pattern working around. Finish off with a slip knot if you are ending your project with the tube spiral. Cut the yarn 2 to 3 inches from the slip knot. Use a yarn needle to weave the trailing end into the tube.
Be careful not to increase or decrease the tightness of your stitches as you work. Changing the size of your stitches will cause your tube to contract or expand. Track the rounds you've crocheted by using a marker, such as a safety pin, attached at the start of each round. Move the marker to start a new round.