Casegoods Construction and Materials. Slides perform better when mounted in rigidly constructed furniture. Construction with soft or thin materials often results in flexing. This causes the drawer to rack from side to side, placing considerable stress on the slides. Do not use drawer slides as support members carrying structural loads.

Location of Pull. The location of the drawer handle affects slide performance. Center pull positions are recommended because they permit a balanced pull force evenly carried by both slides. Side or edge pulls put more force directly on one slide than the other, causing the two slides to progress at different speeds. The additional force required to open and close the drawer hinders performance and shortens slide life.

Installation. Most slide designs require installation in a single position. Carefully study the application before installing the slides in different or abnormal positions.

1.   Orientation. Slides should not be installed in an orientation other than for their intended usage. For example, a slide designed for side mounting may lose 75 percent or more of its load-carrying capacity if mounted flat underneath a drawer.

2.   Location. Drawer construction, pull position, and type of load are all key considerations to determine the best location to fasten the slides.

3.   Balance. Most slides are designed for use in pairs. For example, suspending a load from just one side (cantilevered load) causes excessive stress and may result in premature slide failure.

Fastening. For best performance, slides require proper fastening. Use the recommended fasteners in sufficient quantity to properly secure the slide. Too few fasteners can cause the slide to pull loose and cause damage. Abnormal fastening methods should be carefully evaluated, because methods such as gluing, riveting, or welding may have unanticipated effects.

Alignment. Slides run in a straight motion. The more precisely the slides are aligned, the less chance they will work against each other.

Load Ratings. KV designates drawer slides in “Pound Class” categories, and uses dynamic (rather than static) loading to determine load ratings.

The “Pound Class” categories are used within the slide industry as general guidelines for drawer slide selection. These categories are not the same as actual load ratings. Load ratings vary based on slide length, application, and casegoods construction.

The categories provide a reference point in selecting which slide may fit a particular application. The “Pound Class” designations are not intended as a substitute for actual product testing. Proper slide selection may be significantly different from the “Pound Class” designation, depending on the application or other use factors.

Representative testing of the selected drawer slide in the fully configured application is the only way to assure proper performance, durability, and safety.

Static Loads. A static load is a resting load without any motion. Static load capacity is significantly higher than dynamic load capacity.

Dynamic Loads. A dynamic load is a load in motion. When a dynamic load gains momentum, it induces more stress and fatigue. Slides must withstand more forces when in motion than when still.

Dynamic loads affect the life and performance of any slide. Other load factors affecting performance are:

1.    An evenly or unevenly distributed load
2.    A centered or off-centered load
3.    The load’s center-of-gravity relative to the slide’s centerline-of-travel
4.    The number of cycles
5.    The speed or frequency of the cycles
6.    The length of the cycle stroke
7.    The percent of travel
8.    The stopping force and distance

Abnormal Loads/Vibration. Shipping, abusive loads, and impact loads — even those of short duration — put large stresses on the slide and can cause immediate or premature failure. Excessive or continuous vibrations can also reduce slide performance and life.

Corrosion. Excessive humidity, salts, or other chemical agents can corrode the finish and attack metal or plastic components. The effects may be immediate, or they may develop over time.

Lubrication. Knape & Vogt lubricates slides at the factory. However, contaminants such as dirt, filings, sawdust, paints, etc. can rapidly break down the effectiveness of the factory-applied lubricant.

Temperature. Extreme high or low temperatures can cause lubricants to thin or gel. Extreme temperatures caused by equipment such as finishing ovens can deteriorate a slide’s plastic and rubber components.

Finishing. Overspray from stains, paints, varnishes, or other finishing agents may degrade the quality of a slide’s “fit and feel.” These types of chemical agents can also attack plastic, rubber, and metal slide components. It’s important to properly mask or otherwise protect installed slides before finishing furniture and cabinetry.

Proper slide specification and installation are keys to long and problem-free operation. To help you select the drawer slides best-suited to your specific applications, Knape & Vogt offers a free consultation service. KV also offers a “no charge” testing service.

KV strongly recommends that manufacturers test representative samples of the complete application. Appropriate industry standards should be followed to assure proper performance, durability, and safety.

NOTE: Knape & Vogt’s testing service does not include product cost nor freight cost to or from the KV test laboratories. Product is properly disposed of shortly after testing, unless otherwise requested.