1. Ligature wires: Lock pins :
They are soft stainless steel wires of to 0.011’’ diameter.
They are used to secure the arch wire to brackets.
Elastic ligature rings are also used for ligation,they are available in various colors.
Lock pins :
They are small pins usually made of brass or soft steel.
They are used to secure the arch wire to brackets with vertical slots.

2. Archwire They are one of the active components of fixed appliances.
They can bring about various tooth movements through the medium of brackets and buccal tubes.
Classification of arch wires:
Based on material used:
1. gold and gold alloys
2. stainless steel
3. nickel titanium alloys
4. beta titanium
5. cobalt chromium nickel alloys
6. optiflex arch wires
Based on cross section:
1. Round
2. Square
3. Rectangular
4. Multistranded

3. Comparison of archwires
A Rectangular arch wire is used
Dimension : 0.022’’x0.028’
The basic archwire is formed on an edgewise former using Bonwill Hawley chart.
The arch wire is round austenitic stainless steel wire.
Dimension: inch diameter
This arch wire was produced by A.J.Wilcock of Victoria.