Other kinds of welding. Some kinds of welding do not use an electric arc. They might use a flame, electricity without an arc, an energy beam, or physical force. The most common type of welding that does not use an arc is called gas welding.
TDW - Total Diamond Weight. A term usually used when there is more than one diamond in a particular piece of jewelry. The combined weight of all of the (diamond) stones.
TTY = Teletypewriter. Also known as TDD (Telephone Device for the Deaf) or TT (Text Telephone). In some countries, it is known as a minicom.. TTYs are used by people who are deaf, hard of hearing, or speech impaired to communicate on the phone. A TTY enables users to type and read for communication instead of speaking and listening.