Ball Slide Load Rating Demystified: What It Means & How to Calculate It

When selecting ball bearing slides for your application, one of the most critical specifications to consider is the load rating. But what exactly does it mean? And how can you be sure you’re choosing the right slide for your needs?

Simply put, load rating refers to the maximum weight a ball slide can carry without failure. It’s the threshold beyond which performance degrades, lifespan shortens, or structural failure may occur. Exceeding this limit risks jamming, deformation, or complete breakdown—especially under repeated use.

At Accuride, every ball slide undergoes rigorous testing to determine its load capacity. This isn’t just internal testing—our results are validated by independent third-party agencies such as the Builders Hardware Manufacturers Association (BHMA) and Woodworkers Institute (WI). These certifications ensure that the published load ratings are reliable, repeatable, and reflective of real-world performance.

But here’s what many overlook: load rating is typically specified per pair of slides. For example, if a slide model is rated for 100 lbs (45 kg), this means two slides (left and right) working together can safely support a 100-lb load. A single slide would carry half that weight.

Also, the rating assumes even weight distribution and full extension under static or dynamic conditions, depending on the test standard. Dynamic load (moving) is usually the key metric for drawers and moving platforms.

So, how do you calculate your required load rating?

Weigh your fully loaded drawer or moving component.
Add a safety margin (typically 20–30%) to account for shock, impact, or uneven loading.
Ensure the total load is within the paired slide’s rated capacity.

For instance:
A drawer with a max load of 80 lbs should use slides rated for at least 100 lbs (80 lbs + 25% safety margin). This ensures smooth operation, long life, and compliance with industry standards.

In high-demand applications—like medical carts, industrial equipment, or heavy-duty storage—choosing slides with verified load ratings from trusted manufacturers like Accuride isn’t just smart—it’s essential.

Bottom line: Never guess on load capacity. Rely on tested, certified data. When you understand load ratings, you design with confidence.