Is there biblical evidence of seraphims being angels? I have heard angels and seraphim being used interchangeably. is there any biblical evidence that they are different or the same? The only verse I know off the top of my head is Isaiah 6:2


  Isaiah 6:2 Above it stood the seraphim: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly. (KJV)


My question is whether angels and seraphim are the same thing or not, and why.
Bible Gateway (RSVCE)  - Quick Search: Seraphim return results that show that in the Bible, seraphim is only mentioned in Isaiah 6: A Vision of God in the Temple.

If angel is understood from 


  Used in Scriptural translations for Hebrew mal'akh (yehowah)
  "messenger (of Jehovah)," from base l-'-k "to send."


Only the action of the one of the seraphim in Is 6:6-7 (RSVCE) can be that of a messenger.


  6 Then flew one of the seraphim to me, having in his hand a burning coal which he had taken with tongs from the altar. 7 And
  he touched my mouth, and said: “Behold, this has touched your lips;
  your guilt is taken away, and your sin forgiven.”


Other than that the seraphim are above God's throne, one calling to another


  “Holy, holy, holy is the Lord of hosts; the whole earth is full of his
  glory.”


This appears to be their sole function and purpose in scripture.




  Meaning | SERAPHIM | Jewish Encyclopedia The passages cited
  furnish conclusive evidence against the idea, popular for a time, that
  the seraphim belong to the same category as angels. They have nothing
  whatever to do with the "messengers of God"; in the Jewish conception
  the two have always been distinguished.