The　clamping　force　attenuation　of　the　fasteners　at　the　long-term　service　used　in　steam-tight　joints　may　lead　to　fasteners　loosening,　joint　separation,　leakage,　or　fatigue　failure,　and　even　cause　a　serious　accident.　The　clamping　force　of　threaded　fasteners　is　an　intuitive　parameter　to　characterize　the　service　state　of　the　fasteners,　but　due　to　the　complex　service　environment,　the　acquisition　of　clamping　force　is　difficult.　In　this　paper,　a　single　bolt　joint　was　used　to　study　the　influence　of　the　amplitude　and　frequency　of　the　external　cyclic　load　as　well　as　the　tightening　torque　on　the　clamping　force　loosening.　The　orthogonal　experiment　was　designed　to　reveal　the　characters　of　various　factors　on　the　clamping　force　attenuation　of　the　threaded　fasteners.　The　data　is　fitted　by　the　double　exponential　equation　to　characterize　the　attenuation　of　clamping　force.　The　range　of　clamping　force　attenuation　by　various　factors　was　quantitatively　analyzed　for　further　prediction　and　control.　According　to　the　percentage　of　the　clamping　force　attenuation,　it　can　be　divided　into　two　stages:　the　rapidly　decline　stage　and　the　gradually　decrease　stage.　The　experimental　observations　could　be　used　to　provide　a　reference　for　the　assessment　of　service　status.　©　2022,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.