What yarn is recommended to use with the 4.5 mm (7) crochet hook?

It is recommended that "Weight 2 - Fine" and "Weight 3 - Light" yarn weights are used with the 4.5 mm (7) crochet hook size.

What is the comparable UK size of a 7 crochet hook?

The United Kingdom size of 7 is the same as the US crochet hook size of 7.

The metric size of 4.75 is the same as the US crochet hook size of 7.

The US size of 7 is the same as the metric crochet hook size of 4.75.

US Name:	7
UK Name:	7
Metric Name:	4.75
Yarn Weight:	This crochet hook size works well when paired with the following yarn weight(s). Fine Weight #2: Sport and Baby Light Weight #3: DK or Light Worsted

These free crochet patterns were all created using various yarn types and brands, but all use the 4.5 mm (7) sized crochet hook.