Doubts on whether the carpet is pure or impure
In the name of Allah, the most Beneficent, the most Merciful.
There is a principle in Islamic jurisprudence which is:
“Certainty is not lifted by a doubt.” (Al Ashbah Wan Nadhair p.60)
Therefore, with regards to your question, unless you can clearly and visibly see any impurity on the carpet or on the metal gripper, you should presume the carpet and the metal to be pure and clean.
Sometimes these little doubts can lead to waswasas or Satanic whispers which leads one to have doubts about everything regarding salah, cleanliness and even issues regarding divorce.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham