Crossbow bolts, also known as quarrels, were short, heavy projectiles used with crossbows.

Construction
The bolts were typically made from wood. They had metal tips or heads, often crafted from iron or steel, designed for piercing armour, causing injury, or delivering blunt trauma.

Length
The bolts varied in length but were generally about 30 to 60 cm long, shorter than arrows used with longbows.

Shaft
The cross-section of the shaft was square, triangular or round.

Feathering
Some shafts were feathered (fletched) to help stabilise flight, although many crossbow bolts had little or no fletching at all.

Penetration of Shields or Armour
Their design made them highly effective in combat. Their weight and strength enabled them to penetrate shields or armour that a regular arrow could not.