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A hair iron or hair tong is a tool used to change the structure of the hair using heat. There are three general kinds: curling irons, used to make the hair curly, straightening irons, commonly called straighteners or flat irons, used to straighten the hair, and crimping irons, used to create crimps of the desired size in the hair.
Most models have electric heating; cordless curling irons or flat irons typically use butane, and some flat irons use batteries that can last up to 30 minutes for straightening. Overuse of these tools can cause damage to hair.
Curling irons, also known as curling tongs, create waves or curls in hair using a variety of different methods. There are many different types of modern curling irons, which can vary by diameter, material, and shape of barrel and the type of handle. The barrel's diameter can be anywhere from .5 in (1.3 cm) to 2 in (5.1 cm). Smaller barrels typically create spiral curls or ringlets, and larger barrels are used to give shape and volume to a hairstyle.
Curling irons are typically made of Teflon, ceramic, tourmaline, metal, or titanium, each of which has its pros and cons. The barrel's shape can either be a cylinder, cone, or reverse cone, and the iron can have brush attachments or double and triple barrels.
The curling iron can also have either a spring-loaded, Marcel, or clipless handle. Spring-loaded handles are the most popular and use a spring to work the barrel's clamp. When using a Marcel handle, named after Marcel Grateau, one applies his or her own pressure to the clamp. Clipless wands have no clamp, and the user simply wraps hair around a rod. Most clipless curling irons come with a Kevlar glove to avoid burns.
Some straightening irons are fitted with an automatic shut off feature to prevent fire accidents.
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