Romanization of Greek Greek numerals which employed the entire alphabet, including the nonstandard letters digamma, stigma, or sigma-tau (placed between epsilon and zeta), koppa (placed between pi and rho), and sampi (placed after omega). As revised in 2001, ELOT 743 provides for the uncommon characters to be given (in Greek) as $ for stigma, + for koppa, and / for sampi. These symbols are not given lower-case equivalents. When used as numbers, the letters are used in combination with the upper "keraia" numeral sign ⟨ʹ⟩ to denote numbers from 1 to 900 and in combination with the lower "keraia" ⟨͵⟩ to denote multiples
Torque wrench Torque wrench A torque wrench is a tool used to apply a specific torque to a fastener such as a nut or bolt. It is usually in the form of a socket wrench with special internal mechanisms. It was invented by Conrad Bahr in 1918 while working for the New York City Water Department. It was designed to prevent overtightening bolts on water main and steam pipe repairs underground. A torque wrench is used where the tightness of screws and bolts is crucial. It allows the operator to set the torque applied to the fastener so it can be matched