I had a ‘fridge moment’ while driving home from work today. My knowledge of the X-Men comes form the first three movies and some of the X-Men cartoon series but something odd struck me.
At the start of the first X-Man movie its explained that Professor X can’t read Magneto’s mind when he’s wearing his metal helmet, so how does he read Wolverines mind when his brain is encased in a metal skull?
That is all! 
The helmet is made of a special “You can’t read my thoughts!” metal.
From wiki:
Magneto has been consistently and frequently depicted as able to resist all but the strongest or most unexpected of telepathic attacks. A number of explanations have been proposed for his unusually strong resistance to telepathy, among them: (a) technology wired into his helmet (the explanation given in the X-Men film series and several comic plotlines), (b) some physical aspect of his electromagnetic powers that can interfere with telepathy (he once used the Earth’s magnetic field to dampen the powers of all telepaths within his reach), © latent telepathic powers of his own or (d) sheer force of will (cf. X-Men Vol. 2 #2). The theme of latent telepathic powers has been explored in a number of stories, among them the Secret Wars limited series.
How convenient!
How ill-defined!
Thanks! 
Pretty much. It’s not that Professor X can’t read thoughts through any metal; it’s the particular metal from which Magneto’s helmet is made which blocks Xavier’s telepathic power.
Spoiler from X-Men: First Class follows:
In that movie, the helmet originally belonged to Sebastian Shaw, the villain of the film. Magneto takes the helmet from Shaw, and uses it to keep Xavier (who had become a close friend) out of his head when he parts ways with the X-Men at the end of the movie.
I read the X-Men books voraciously in the '80s; ISTR that Juggernaut had a helmet which had a similar ability to block telepathic powers (he was otherwise largely invulnerable).
Scratch “largely”, unless it’s been changed since I’ve last seen him. I quite like how the Marvel wikia puts it, describing plasma cannons as an obstacle that is capable of slowing him down.
Well if you really want your mind blown, Colossus currently has the Juggernaut powers.
Yeah, nothing short of the apocalypse is likely to injure him. There’re few people more invulnerable in all of Marvel: the Hulk, probably, but that’s partly because he layers multiple absurd defenses instead of sheer unstoppable unkillable-ness.
Didn’t Xavier even help in the construction of the helmet?
And I understood it to not be the material of the helmet, but the details of its design: It’s not just a hammered piece of sheet metal.
According to What If- Professor X Were Juggernaut?, Magneto made the helmet from ore using nothing but his electromagnetic powers.
Silenus Has it. According to multiple issues of X Men, one can be trained to block their thoughts from telepathic scanning. According to an issue of Secret Wars ( I forget which one. Xavier is trying to telepathically contact Galactus. Magneto tries to help and is told “Magnus, no! You’re creating a surge!”) and others, Magneto has some telepathic ability of his own. And, as noted above, the mystical metal of Cytorak blocks telepathic powers- so it’s plausible that the master of magnetism could find a way to replicate that.
Wolverine has at times been shown to be fairly hard to read telepathically, though not immune, and often chalked up to his mismash of fake memories and such.
Uh, the properties of that metal are why he uses that material for his helmet. He didn’t just find a helmet in a dumpster somewhere and it just-so-happens to block mind powers.
His hat’s tinfoil, obviously.
[hijack] juggernaut’s x’s brother, no? stepbrother? is that not the case in every comic? it certainly wasn’t touched upon in the movies. [/highjack]
Half-brother.
They seem to flip-flop on that a bit…one story they’re half-brothers, the next they’re step-brothers.
The wiki hosted by Marvel right now lists them as step, with Xavier’s mother marrying Marko’s father after the deaths of Xavier’s father and Marko’s mother.
Edit: sigh, actually, it lists them as both. Their character pages list them as step-brothers, Juggernaut’s disambig page lists them as half-brothers.
Wolvie’s skeleton is not completely metal, is it? ISTR it being said that his bones were “laced” with adamantium.
The Juggernaut cannot be stopped by inconsistency!
“Infused” and “bonded” are the words they usually use.