San (letter) San (letter) San (Ϻ) was an archaic letter of the Greek alphabet. Its shape was similar to modern M, or ϡ, or to a modern Greek Sigma (Σ) turned sideways, and it was used as an alternative to Sigma to denote the sound . Unlike Sigma, whose position in the alphabet is between Rho and Tau, San appeared between Pi and Qoppa in alphabetic order. In addition to denoting this separate archaic character, the name "San" was also used as an alternative name to denote the standard letter Sigma. The existence of the two competing letters Sigma and San is
Torque screwdriver to at least 27Nm, with speeds of up to 2000 RPM. Cordless torque screwdriver are powered by batteries, usually rechargeable batteries with voltages from 3.6 to 18 volts. Dedicated screwdrivers for domestic use tend to operate off 3.6 to 4.8 volts and have relatively low maximum torque; drill/drivers operate off higher voltages and can deliver higher maximum torque. Cordless torque screwdrivers are used for the same applications as cordless screwdrivers without torque control. The pneumatic torque screwdriver is widely used for assembly requiring higher levels of torque. These tools are commonly used in automotive, aerospace and marine manufacturing. Pneumatic tools