Request to obtain round seal for metal junction (6)
I believe the answer is:
gasket
'seal for metal junction' is the definition.
I can't judge whether this defines the answer.
'request to obtain round' is the wordplay.
'request' becomes 'ask' (to ask is to request something).
'to obtain' becomes 'get' ('get' can be a synonym of 'obtain').
'round' is an insertion indicator.
'ask' put inside 'get' is 'GASKET'.
Can you help me to learn more?
(Other definitions for gasket that I've seen before include "Seal at a pipe point" , "Compressible piece of rubber forming a seal" , "external sealing device" , "Ring for sealing a pipe joint" , "Flat sheet used as engine seal" .)