Although most designers are familiar with the basic criteria used to select slides for load bearing applications (drawer size, anticipated load, and available side space), a closer look at these criteria and other pertinent factors is necessary to make sure that the best slide is chosen for the project.
Drawer or Chassis Width
Whether the slides are intended to hold a drawer, component, or chassis, the width of the pullout unit has a large effect on performance. If the slide does not have the strength and load capacity that corresponds to the width, it can cause racking or side-to-side movement. Excessive racking causes instability and can result in drawer failure.
When widths are 24” or greater, adding stability by using a slide with a larger cross section and a higher load rating is often the best solution.
When designing slides into a product, determining the load capacity required is typically based on the estimated weight of the contents, or net load of the drawer. However, the weight of the actual drawer, tray, or framework that will carry the load is often overlooked. Although this may seem to be an obvious point, a miscalculation here will negatively affect performance.
Additionally, choosing a slide with a sufficient cross section and load capacity will prevent heavily loaded units from sag or deflection when fully opened.
Most manufacturers specify a maximum load rating for each product. That maximum is apt to be based on specific conditions, such as a pair of 18" slides mounted on a 16"-wide drawer and tested to a particular cycle count. Check with your supplier to determine how the product’s load capacity is effected if your application calls for a pullout unit that is deeper or wider than the tested specifications.
Available Side Space
Side space is the amount of room needed between the pullout and the case or cabinet. Providing sufficient side space is critical for optimal slide movement, and as mentioned previously, based on width and load factors, the designer must evaluate whether the project requires a slide with a larger cross-section width than the design initially intended. It is difficult and costly to increase side space if this dimension is not considered early in the design stages.
Slides rated for heavy-duty applications have a cross section dimension of .75" or greater, which means a minimal difference of 1.5" must be considered between the width of the pullout unit and case. The use of brackets to mount slides is another factor that may affect the amount of side space needed.
Usage & Lifetime
Will usage be infrequent and require a low cycle count or will the application require greater durability with usage reaching 50,000 to 75,000 cycles? Another factor to consider when researching slides is that much of the load rating and cycle-life criteria published may be geared to less demanding applications, so it's important to inquire as to what can be expected in your specific application.
Be sure to choose slides designed to withstand exposure to extreme temperatures and moisture. High or low temperatures can negatively affect slide performance, inhibiting smooth travel and movement. In the case of moist environments, seek a slide finish that resists corrosion or has critical components made of stainless steel or aluminum. Find out what kind of salt-spray testing has been conducted; will the slides withstand 96, 200, or 500 hours in a corrosive environment?
Consider extension (travel) as well as special options, such as soft closing or locking, all of which may further enhance the product.
If an off-the-shelf solution won't meet the specifications, be sure to consider custom options. Manufacturers can offer affordable customized options, such as additional slide lengths, varied hole patterns, materials, finishes, and mounting brackets in order to help meet the specific project needs.