Knitting Machine Gauge or Size explained

Knitting machines come in different sizes or gauges, just like knitting needles come in different sizes. Each machine is designed to knit a specific size range of yarn. 

For instance, Bulky weight yarn, fits the Bulky machines.

Worsted weight yarn (e.g., Red Heart Super Saver) fits the bulky machine and mid-gauge machine. 

Double Knitting weight yarn fits the mid-gauge machine. It's too fine for the Bulky.

Fingering weight or sock yarn, fits the standard gauge machine.

There are dual gauge machines like the Studio LK150 that can knit both worsted and double knitting yarn.

What exactly is gauge? This is the spacing between each needle on the knitting machine. The bulky has 9mm between each needle. The mid-gauge (depending on brand/model) has 6, 6.5 and 7mm between each needle.

The standard gauge machine has 4.5 mm between each needle.

The hook of the needle is sized to fit around the yarn the machine uses to knit. The bulky machine having the largest hook, the standard gauge have the smaller sized hook. The yarn used has to fit into the hook. If the yarn is too thick, the hook will pierce the yarn and either jam the machine or shred the part of the yarn that is not in the hook.

The mid-gauge and bulky gauge are the most popular gauges if you want to use hand knitting yarn and have a hand knitted look. 

The standard gauge or 4.5 mm machine has finer fabric results and looks more like commercially produced knitting.