Shardblades

[Steel Inquisitive]

So this question is mostly @Calderis fault.... So blame him 

Since oathbringer we found out that shardblades can cut spren. (kaladin defending gavinor.) So why don't shardblades cut each other? Shardblades are the physical manifestation of spren.... Shouldn't they be cutable? As I recall most shardblades aren't double -bladed so would the non sharp edge be able to be cut? 

What about live blades against dead blades?

[Rossamund]

That instance was unusual and we'll probably have to wait to the next book till we get a good understanding.

Shardblades don't cut each other. Think of it as the difference between bringing too steel knives against each other and cutting steel wool with a steel knife. Shardblades are tough that spren wasn't.

[Themasterhunter]

I think a good thing to remember is that when a shardblade is manifested, it is literally brought into the physical realm. the fact that a blade is dead doesn't matter, because it still manifests the same way.