Solar System level consistently
It's considered one of the most durable objects in the Marvel universe even by heavy hitters, which is why Wolverine can always take bloodlusted hits from Hulk and get right back up it's also why his claws have the sharp cutting power to cut/maim heavy hitters like Thor/Hulk and
especially Thing. IIRC They tried to equate Raiden's high-frequency blade=antarctic vibranium but those aren't really the same since vibranium only really works because it's an anti-metal (it's adamantium's kryptonite)
Whereas the High Frequency Blade doesn't bypass durability it just weakens the durability of the molecular bonds that it strikes making it easier to cut. It's never cut a material anywhere near as durable as Adamantium and it has shown an upper limit when Raiden broke his HF blade on Armstrong's nanomachine skin. If say Muramasa didn't break like Raiden's HF blade did and he did attempt to lower the adamantium's durability down enough to be able to cut it (let's say the weakening effect directly correlates to the force of each strike) with the 100 kt they gave Raiden's cutting power (and scaling adamantium's durability from Thor/BRB's breaking a star eater) it would take 6.602136e+31 full-powered strikes to the same area for him to cut it. Which even factoring in their Relativistic reactions spot for Raiden (11.7% c/35,188,682.02m/s) would still take 1.8762101e+24 seconds (59 Quadrillion years) of striking the same spot at full strength to cut it or the more likely result would be that it would break like with the aforementioned Armstrong incident.