We all need high quality metal (HQM) whether it's for crafting guns to go on the offense or upgrading your bunker for offline defense. But your base location, team size, pvp prowess, and many more things including simply how much you need will all be a factor. I'll cover the spread of what I find to be the most effective ways to farm HQM.

Quick sidenote, since making this video you can no longer use the metal detector in safe zones. It can still be surprisingly good at farming loot, but it is not as risk free anymore.

Some more relevant info:

• I forgot to put Missile Silo as a way to farm Diesel
  
• Since many have asked about map tiers, here's the devblog[rust.facepunch.com] about it.
  
• The treasure quest at Ranch that costs 25 scrap commonly drops HQM or high value items worth HQM.