An x-ray tube includes a cathode and a target assembly positioned to receive electrons emitted from the cathode. The target assembly includes a target and a spiral groove bearing (SGB) configured to support the target. The SGB includes a rotatable component having a first surface and a first material attached to the first surface, a stationary component having a second surface and a second material attached to the second surface, the stationary component positioned such that a gap is formed between the first material and the second material, and a liquid metal positioned in the gap. At least one of the first and second materials has a thickness greater than 0.1 mm.