KitchenAid ranges (a Whirlpool brand) generally use 6mm D-shafts.
OEM KitchenAid knobs are often $25–$100 each — when they're still made. Design a replacement
with the exact bore for your shaft, in any color, printed in durable PETG and shipped for about $20.
Don't see your part number? Pull the broken knob off, check the
shaft (D-shafts: measure the diameter and the flat), and design yours — the bore presets cover
6mm, 8mm and 9mm D-shafts.