A machine tool has pass-through pallet loading allowing pallets to be loaded or discharged from either side of the machine. The pallet receiver is mounted on the X-axis of the machine, and the pallet is loaded onto the pallet receiver with the pallet in a vertical orientation. Cross axis rollers on the pallet receiver support the pallet and spacing rollers maintain the pallet spaced from Z-axis locating pads as it moves to a centered position on the pallet receiver. The Z-axis pads present a relatively large surface area to the rear face of the pallet, and are configured to provide vacuum clamping to lock the pallet in all three axes once it is centered on the pallet receiver. A rotating key is provided to center and lock the pallet relative to the pallet receiver before the vacuum clamping is applied.