Polycarbonate or nylon – an inexpensive option that is suitable for all players.
Aluminium – these are stronger, more durable, and more rigid than plastic darts, however they can be bent easily. Aluminium darts rarely break, but they can come loose as a result of vibrations through standard use. To counteract this, use o-rings or Gomus to help keep the stem tight.
Carbon – this includes carbon fibre stems and carbon composite stems. Carbon stems are lighter than aluminium but are strong and durable. They don't loosen in the barrel either, but they can be more expensive.
Titanium – one of the most expensive options there are, but these stems are virtually unbreakable!
Composite – combination of titanium and carbon, or aluminium and plastic or plastic and carbon, giving you greater flexibility in finding the right set-up for your throw
Spinning – spinning stems don't alter your throw. Instead, they allow for tighter groupings of darts on the board as the stem lets the flight of a dart already in the board spin out of the way if it is hit by another dart. This prevents your flights from getting damaged and it helps reduce dart on flight deflections.