{
  "slug": "head-gas-bearing",
  "term": "HDD head gas bearing",
  "aliases": [
    "head air bearing",
    "slider gas bearing"
  ],
  "definition": "An HDD head gas bearing is the thin moving gas film whose pressure supports the head-carrying slider against its suspension load.",
  "note": "The established name air-bearing surface (ABS) also appears in helium research. Liu's chapter 8 numerically couples gas flow and thermal deformation for one slider: unheated and heated clearance respond differently to helium fraction [gas-model]. This is not the spindle bearing, and its behavior cannot be inferred from bulk gas density alone [card].",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "head-disk-interface",
    "flying-height",
    "thermal-flying-height-control",
    "helium-hdd"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "gas-model",
      "title": "Nan Liu (2010), UC Berkeley dissertation, chapter 8: TFC sliders in air-helium mixtures",
      "url": "https://cml.berkeley.edu/wp-content/uploads/gold-reports/G10002.pdf",
      "accessed": "2026-10-16"
    },
    {
      "id": "card",
      "title": "Hesela: helium HDD construction and evidence boundaries",
      "url": "https://hesela.com/tech/helium-hdd/",
      "accessed": "2026-10-16"
    }
  ],
  "updated": "2026-10-16"
}