About the Box Thickness of Kitchen Cabinets
The thickness of cabinet box side panels varies by manufacturer and product line. Thicknesses typically range from 3/8" to 3/4".
Your cabinets hold a substantial amount of weight from stacked dishes, canned goods and other kitchen items. Thinner panels may bow or twist, particularly if they're not reinforced in some way. Thicker panels provide the support you need.
3/4" Thickness for Cabinet Boxes 
Cabinet boxes that use a 3/4" thickness for their material are the strongest and most durable. They will support whatever you put in them and will not be very susceptible to warping. Many cabinet lines offer this at the highest upgrade level but it is standard on all of Mei Kitchens’ cabinets.
5/8" Thickness for Cabinet Boxes 
Many cabinet lines use a 5/8" thick material for their boxes. This thickness is not the best quality but if coupled with a strong material, it should be an ok compromise.
1/2" Thickness for Cabinet Boxes 
This is where quality begins to decline quickly. Cabinets built with 1/2" thick materials start sacrificing quality. You can see how much of a difference it really is from 3/4" and that it is more prone to any type of damages or warping.
Durability will start to be compromised from here on.
3/8" Thickness for Cabinet Boxes 
The visual difference from 3/8" to 3/4" should be all you need to see to know that this is just not a good idea. It is extremely thin and should definitely be avoided if you are looking for strong and durable cabinets.