Screw Caps Alternative ways to recycle Put in Garbage Remove From Bottles and Jars Metal jar lids and bottle caps should be removed and disposed of separately from plastic and glass. Plastic Caps Are Different Plastic caps have separate disposal instructions. Find out how to dispose of plastic caps. Recycle Metal Jar Lids Metal jar lids greater than 2-3 inches in diameter can be recycled. Make sure they are separated from their jars so they can be sorted correctly. Alternative Ways to Recycle Metal Screwcaps Are Scrap Metal Metal screw caps can be collected and recycled with other scrap metal. Simply separate aluminum caps (non-magnetic) from steel caps (magnetic).