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Are Garbage Disposals Universal (Yes, They Are)

There are around a hundred garbage disposal models made by different brands like Waste King, InSinkErator, Moen, etc. But do they all fit all sinks?

Garbage disposals are universal, they are made to fit all kitchen sinks with standard drain hole sizes of 3.5 to 4 inches. Since this is the standard drain hole size of all kitchen sinks, you can install a garbage disposal on any sink.

There are a few exceptions to the above, though. Kitchen sinks made of metals like stainless steel or copper are very thin, so there is no problem connecting garbage disposals to them. However, in the case of fireclay sinks, they are thicker; you will need to use an extended sink flange to connect garbage disposals.

Why garbage disposals are universal

As mentioned earlier, all kitchen sinks have a universal drain size ranging from 3.5 to 4 inches. This is to make the sink compatible with any standard drain pipes in the US. Since garbage disposals are installed at these sink drains, they also need to have a standard size.

As a result, any garbage disposal can be installed on any standard kitchen sink.

But where exactly is this ‘universality’? Does this mean all garbage disposals have the same height, width and grinding power? How are they made compatible with all sinks?

The secret is, all garbage disposals have the same size mounting assembly and drain outlet.

The mounting asseblies of all garbage disposals have the same size

The installation of any garbage disposal follows the same procedure. It is installed on a sink using a sink mount assembly. This consists of a flange, which is inserted through the drain hole of the sink, and a mounting assembly to which a garbage disposal can be hooked up by a simple twist and lock.

Connecting a garbage disposal to a sink
Connecting a garbage disposal to a sink

There are two types of mounting assemblies; 3-bolt and EZ. 3-bolt mounts are used mainly by brands like InSinkErator and Moen, whereas EZ mounts are mostly used by brands like Waste King and Waste Maid. The installation of garbage disposal using these mounting assemblies are slightly different. However, they can be used on all kitchen sinks.

Here is a detailed installation video of a garbage disposal that uses a 3-bolt mounting assembly;

As mentioned before, any garbage disposal using any of the mounting assemblies are compatible with any sinks that have a drain hole size of 3.5 to 4 inches.

All garbage disposals have the same drain outlet size

All garbage disposals, irrespective of their brand names, have a standard drain size of 1.5 inches. This is exactly the standard size of drain pipes in all households, whether one uses a garbage disposal or not.

Connecting a garbage disposal to the drain pipes
Connecting a garbage disposal to the drain pipes

What does this mean to you? It means that you can buy whichever garbage disposal you want and install them without changing the existing pipe connections. This makes the process of installation much easier.

Are garbage disposals compatible with a farmhouse sink?

Even though garbage disposals are universal, there are certain constraints like space that check the installation of some of these units under deep sinks like farmhouse sinks.

Image of a farmhouse sink
Image of a farmhouse sink

Garbage disposals can be installed on farmhouse sinks; however, not all models can be. As you know, a farmhouse sink is deeper than a standard kitchen sink. Therefore the space available under the sink is limited. Garbage disposals with large heights cannot be installed in such short spaces.

In such cases where deep sinks are used, only compact garbage disposals like Evolution Excel or Evolution Compact can be installed. This limitation is not due to the incompatibility of the garbage disposals to the kitchen sink but rather the limited space availability under the sink.

Further reading: Short garbage disposals for deep sinks

Are my existing electrical compatible with a new garbage disposal?

All garbage disposal units in the USA operate on 120 volts, and those sold in the UK operate on 240 volts. So whatever disposer unit your purchase, it will be compatible with your existing electrical. If you have a plug socket under the sink, or you use an air switch which I highly recommend, buying a garbage disposal with a pre-installed power cord makes the installation easier.

Additional Reading:

Are garbage disposal splash guards universal?

My name is Thomas Anderson, author of DisposalQA. I have 15 years experience working as a plumber in CA, and this is where I answer common questions about garbage disposals.

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