An axle stand is a device that securely supports the axle at one corner of a vehicle, so that a pair of axle stands enables a person to work safely underneath. Unlike a trolley jack, which has seals that can fail (with potentially disastrous consequences for anyone underneath), axle stands are held in place by either pegs or ratchets. Also they allow the weight of the vehicle to be spread evenly over two points.

Stands should be marked with a Safe Working Load (SWL). The larger the number, the better. As each stand supports only corner of the vehicle, a one-ton rating is more than enough for most applications. However, be aware that some manufacturers give a "per pair" rating.

Another important factor is the size and shape of the saddle that supports the axle. A wide top with a cupped design is preferable, as it gives more stability. However, the cup shouldn't be so deep that its upper edges can damage the underside of the vehicle. An iron saddle is less likely to cause damage than a steel one.

Ratchet stands are easier to use than peg types and afford a wider range of height settings. Other factors to look for include feet on each leg to spread the load and prevent the stand digging into the floor. As far as height goes, an 11-inch (280 cm) maximum is fine for the average car; owners of 4x4s should add an extra 4 inches (100 cm) to this.