Strut top bushing

[tektic]

So I need a shoulder bushing 15mm id 20mm od for the coilover spring top perch I bought but I can only find it in brass. Is that going to work or do I absolutely need steel? It’s a radial bearing upper spring seat for a 2.25” spring . I’m going to be using it with stock style upper strut mounts and the shoulder part will be between the two pieces.