Spacer key used for installation of a head gimbal assembly (HGA)

An apparatus for use in attaching a head gimbal assembly (HGA) onto an actuator arm of an actuator assembly during an HGA installation process. The apparatus includes, a central body portion with a base support surface; and a pair of support arms extending from the central body portion forming a channel sized to accommodate expansion of an attachment aperture of an actuator arm during the installation process. Each support arm includes, a first and second support surface offset from and parallel to the base support surface. A first support arm thickness is formed between the first support surface and the base support surface, while a second support arm thickness is formed between the second support surface and the base support having a thickness less than the first support arm thickness. Each support arm thickness supports a corresponding HGA adjacent actuator arm during the installation process.