Choosing the Right Drawer Slides


Selecting the right drawer slides for your application can seem complicated.  There are so many types available on the market, some very complicated to install and require a professional and others very simple and can be done by anyone. So how do you choose from all the options?

There are three basic things you need to consider when choosing the ideal drawer slides.

  1. Drawer slide travel or extension: This refers to how far open you want the drawer to fully extend. 
  2. Weight capacity:  Most big box store style drawer slides are cheaply made and don't offer much in a way of weight capacity. To make things worse, when the drawer slides are fully extended that weight capacity decreases significantly, typically by 50%.  It is important to determine if the weight capacity refers to when the drawer is closed or open.  All Firgelli drawer slides weight capacities are rated for fully open.  Hardware stores usually give this weight capacity when closed, so be careful. 
  3. Mounting location: Side mounted drawer slides are the most popular and easiest to install.  Center mount and undermount are also options.

What Length of Drawer Slides do you need?

drawer slides extension description

Drawer slides generally come in extension lengths between 10 and 32 inches to fit a wide range of cabinetry requirements. We recommend you choose a slide length that corresponds to the size of your drawer, so you have to first measure your drawer depth.  Once you know the length of extension required you also need to measure the closed length to make sure that whatever drawer slide length you buy will actually fit once closed without sticking out of the cabinet.  For this reason you probably want to pick a telescopic style drawer slide. 

What is a Telescopic Drawer Slide?

Telescopic drawer slides typically have three sections within each slide.  This, for example, allows for a 20" extension even when the drawer slides are 20" in length when closed.  If this was a two section drawer slides it would not be possible to extend 100% of its closed length, the maximum you could get would maybe be 15" but the weight capacity would be very low as a result. 

How to choose the right drawer slides

Next, take into consideration the type of mount and measure out the slide length requirement accordingly. If you are going for side or side-under mount slides, you have to measure the distance from the inside face of the back of the cabinet to the front edge of the cabinet. Then, subtract  approximately 1” from that for the required slide length.

In the case of center slides, just measure the length of the drawer, as the slide length has to be equal to that. However, be aware that there is a problem with this mounting style that we will go into in the next section.

It is very important to get the measurements correct. If your slides are shorter than the drawer length, they may not provide  enough opening length or adequate support once fully opened. They might even cause the drawer to give out and fall off at some point. 

How Strong of Drawer Slides do I Need?

The weight capacity determines the maximum load a drawer slide will be able to handle. Determining the typical holding capacity of the drawer and taking that into account is especially important if you are installing slides for heavy-duty use because most big box store type drawer slides don't offer weight capacities much over 50 lbs weight.  All of Firgelli's drawer slides start at 400 lbs weight capacity.

Drawer slides are usually rated for 50 - 100 lbs and for household purposes slides with lower weight capacities are fine and will do the job nicely. Our specialty when it comes to drawer slides is for heavy duty and extra long stroke drawer slides.  

Mounting Types

Deciding the mount type is important but more than likely it has already been decided for you by the cabinet design.  There are three mount types: side mount, center mount, and undermount. When determining the most suitable mount type, you have to consider the space between the cabinet opening and the drawer box.

1. Side-Mount

Side mount drawer slidesDrawer slides for side mounting usually come in sets or pairs with slides for each side of the drawer. They come in either roller or ball-bearing mechanisms and require a clearance of at least 1/4″ between the sides of the cabinet opening and the slides. There are basically two types of drawer slides suitable for side mounting: telescopic extension slides and roller bearing slides.  The simple two section roller bearing slides are what you will find in the majority of kitchen cabinetry.  They are cheap and widely available but they do not allow for a very long extension and their weight capacity is limited to 50 lbs. 

Telescopic extension slides offer any extension length you require and can hold huge amounts of weight.  Firgelli heavy duty drawer slides can carry up to 500 lbs of weight with extensions up to a whopping 60 inches.

Installation of both these types of drawer slides is pretty simple and can be done by anyone with a tape measure, screw driver and wood screws. 

2. Center Mount

center mount drawer slides

Center mount drawer slides are sold individually as they mount under the drawer in the center and lay flat.  The downside of this is that the drawer slide looses 80% of its weight capacity when turned in this orientation, however the benefit is that the slides are hidden even when the drawer is open and you only need one per drawer.   This style is ideal if you want to keep the slides hidden and have a low weight capacity.  The required clearance will be determined by the slide’s thickness in this style. 

3. Undermount

Drawer Slide side under Mount Type

These slides are the ball-bearing style, and they come in pairs but don't extend the full length  that matches the closed length. They are mounted to the cabinet’s sides and are connected to locking devices that go on the underside of the drawer. They require less clearance, usually around 3/16″ to 1/4″ for each side and may be a little more work to install. 

If you are looking for quality drawer slides with exceptional weight capacity and extension length, see the links below to Firgelli Autmations drawer slides.

10" to 50" Drawer slides with 400-lbs weight capacity

40" to 60" Drawer slides with 500-lbs weight capacity

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