High-speed　rotation　instruments　that　apply　gradient　hypergravities　can　induce　local　variations　in　structure　and　thus　induce　cracking.　Rotation-induced　hypergravity　is　a　kind　of　gradient　force,　and　it　has　a　gradient　value　that　depends　on　distance　and　local　weight.　Conventional　mechanical　testing　applies　a　constant　force　or　periodic　force　instead　of　true　gradient　hypergravity　to　rotating　components.　In　this　study,　a　dedicated　instrument　was　designed　and　assembled,　and　a　special　sample　of　1060　aluminium　slats　with　multiple　thinned　necks　was　used　to　reveal　the　difference　between　gradient　hypergravity　and　conventional　constant　forces.　Hypergravity　caused　more　significant　damage　to　the　aluminium　slat,　and　the　ultimate　crack　strength　was　approximately　10%　of　the　strength　observed　under　the　constant　force　applied　at　the　same　temperature.　All　the　samples　cracked　on　the　inner　neck　which　bears　the　highest　hypergravity.　Two　types　of　cracks　were　categorized　based　on　the　relative　extension:　type　Ⅰ　mode　cracks　occurred　in　the　centre　of　the　neck　with　long　extension　before　cracking　under　hypergravity　more　than　3.5　MPa,　while　type　Ⅱ　cracks　occurred　in　the　root　of　the　neck　without　long　extension　before　cracking　under　hypergravity　less　than　3.5　MPa.　Combination　of　hypergravity　and　torsional　force　in　high-speed　rotation　system　prompt　cracking　and　exhibit　similar　microstructure　with　that　under　high　constant　force.　Typical　cracking　and　its　microstructure　under　the　effects　of　hypergravity　and　temperature　provided　a　convenient　and　practicable　method　for　evaluating　service　safety　of　commercial　rotating　machines　for　industrial　applications　and　raw　alloys.　©　2024　Elsevier　B.V.