Here is a recommended 'Metal' Supply Line
These are supply lines that are sold at local home centers.
Usually they don't meet local codes, but are available and should
NOT be used!
Notice the 'failed' supply lines above, they may look strong on
with the metal braid, but inside it's a soft flexible pipe that in
this case has failed.
If the customer had installed the right kind, I probably wouldn't
have been called for this repair.