The plastic knob that regulates my crock pot broke right in half.

If super glue isnt strong enough as an adgunct -epoxy putty around the knob circumferentially. Every DIY and craftsperson should have this valuable putty.It does so much more than plumbing.

Ive repaired candlesticks, jewelry, elliptical foot pedals, pottery, ceramics, concrete dog, wood rot and firewire cable damage with the putty and so much more!

This putty stick is my all time favorite repair crafting item to have on hand. Its less than six dollars at your local Lowe's hardware store in the plumbing department. You can buy similar brands for twice the cost in boating rv and wood repair departments......

Putty characteristics

Steel-filled material, mixes in your hand and hardens in minutes

Suitable for plastics, metals, fiberglass, concrete and ceramics

May be drilled, tapped, filed, sanded, sealed and painted when hardened

Non-toxic material contains no solvents

Will not shrink

I strongly suggest your considerion of the epoxy putty for your repair needs.

https://www.oatey.com/2373255/Product/Oatey-Fix-It-Stick-Epoxy-Putty

Glue it together, but make sure you can get it back onto the crock pot so that you can use it right.

I have had good luck glueing plastic objects with crazy glue. Wear plastic or silicone gloves though, putting them on before you glue the knob, as the glue is wicked enough to rip your skin off.

Glue the pieces, and hold tightly together until the glue sets dry.

fun fact - super glue a sterile version...is used to seal surgical incisions.