A bradoon is generally thinner because it is used in combination with a weymouth
Sweet iron develops through contact with (air) moisture surface rust that tastes sweet and stimulates the saliva production in a natural way. This will cause the horse to start foaming more, which ensures better acceptance of the bit. This rust process (oxidation) changes the blue color of the TRUST bits into brown. When temporarily not using a sweet iron bit, an orange-brown rust layer may form on the mouthpiece. This can easily be removed by removing the bit with a damp cloth.