How Drawer Slides Work

4 min readFeb 19, 2024

Drawer slides are the mechanism that drawers use to move. They are ubiquitous and mostly invisible, except when they don’t work as we expect. Despite how many take it for granted, this underlying technology in drawers is essential to supporting low friction interactions in our daily lives (pun intended).

Drawer slides invisible to most users, until they don’t work like they should

To function, drawer slides must hold the drawer in place and provide support for the drawer and its contents. The simplest drawers¹ use a groove and rail mechanism. In this design, an interlocking groove slides along a track.

This track provides both a downward and an upward force to keep the drawer in place. The rail and groove are interchangeable, so long as they are used together. In other words, the drawer may have a groove and the enclosure may have a rail or visa versa.

Sketch of a groove and rail drawer slide.

While this interlocking design is simple and affordable to construct, it is sometimes difficult to move a drawer that uses this mechanism (especially if the drawer is full of heavy items). This resistance is caused by friction from the rail and groove sliding along one another.

Kinetic friction makes groove and rail drawers difficult to move (left), other designs use rolling friction to reduce force required (right)²

However, several strategies have been used to overcome this frictional force. Most commonly, drawer slides leverage rolling friction to reduce the total force required to move the load by a factor of 100 to 1000 ³. For instance, some drawer slides use a roller which slides along a track. These designs are still relatively easy to manufacture and low cost, but they are much easier to move than a groove and rail design¹.

Product image showing two interlocking parts of rolling drawer slides (left) and diagram of assembled rolling drawer slides (right)⁴

Despite the lower force required to use a rolling drawer slide compared to a groove and rail design, this design can sometimes still be difficult to pull when the load on the drawer is high from heavy contents. In addition, like groove and rail, these designs can only be extended to the length of the drawer.

To overcome these shortcomings, a third drawer slide is used — ball bearing mechanisms. Similar to rolling drawer slides, ball bearing drawer slides utilize rolling friction, which makes them easier to move smoothly. However, this design utilizes several metal ball bearings on a track to make drawers slide with minimal friction. Compared to rolling drawer slides, ball bearing drawer slides are able to move freely with higher loads¹. However, these mechanisms more complex and expensive.

Notably, ball bearing drawer slides enable drawers to extend beyond the length of the drawer as they are able to hold more weight and can be combined to produce longer drawer extension. For instance, full extension drawer slides based on an interlocking ball bearing-based mechanism enable users to pull out the drawer farther than its length.

all bearings inside of drawer slide⁷ (left), side view of full extension drawer slide with two sets of interlocking rails and ball bearings⁵ (center), drawer extended past drawer length using ball bearing drawer slide⁶ (right)

Although ball bearing drawer slides are easy to move, they cause the drawers to move too easily — making them prone to slamming. To solve this issue, soft close drawer slides have been introduced. Soft close drawers use a combination of a latch, spring, and damper, which uses fluid and a spring inside of a closed chamber to resist forces applied to it.

This combined design first latches onto the drawer as it is nearly closed to prevent the damper from pushing it back open. Then, the damper slows the drawer, absorbing any remaining momentum from the drawer closing. Finally, tension from a spring pulls the drawer the rest of the way closed.

Soft close drawer mechanism on ball bearing drawer slide⁸

References

How Drawer Slides Work

Written by Casey Hunt