10% off) as one would expect (a bell-curve), but rather be in two groups – either between 5 and 10% too high or 5 to 10% too low (but not closer to 100 ohm than that) because any resistors the factory had measured as being less than 5% off would have been marked and sold as resistors with only ±5% tolerance or better. When designing a circuit, this may become a consideration. This process of sorting parts based on post-production measurement is known as "binning", and can be applied to other components than resistors (such as speed grades for CPUs). SMT resistors Surface mounted resistors of larger sizes (metric 1608 and above) are printed with numerical values in a code related to that used on axial resistors. Standard-tolerance surface-mount technology (SMT) resistors are marked with a three-digit code, in which the first two digits are the first two significant digits of the value and the third digit is the power of ten (the number of zeroes). For example: 334 = 33 × 104 Ω = 330 kΩ 222 = 22 × 102 Ω = 2.2 kΩ 473 = 47 × 103 Ω = 47 kΩ 105 = 10 × 105 Ω = 1 MΩ Resistances less than 100 Ω are written: 100, 220, 470. The final zero represents ten to the power zero, which is 1. For example: 100 = 10 × 100 Ω = 10 Ω 220 = 22 × 100 Ω = 22 Ω Sometimes these values are marked as 10 or 22 to prevent a mistake. Resistances less than 10 Ω have 'R' to indicate the position of the decimal point (radix point). For example: 4R7 = 4.7 Ω R300 = 0.30 Ω 0R22 = 0.22 Ω 0R01 = 0.01 Ω 000 and 0000 sometimes appear as values on surface-mount zero-ohm links, since these have (approximately) zero resistance. More recent surface-mount resistors are too small, physically, to permit practical markings to be applied. Precision resistor markings Many precision resistors, including surface mount and axial-lead types, are marked with a four-digit code. The first three digits are the significant figures and the fourth is the power of ten. For example: 1001 = 100 × 101 Ω = 1.00 kΩ 4992 = 499 × 102 Ω = 49.9 kΩ 1000 = 100 × 100 Ω = 100 Ω Axial-lead precision resistors often use color code bands to represent this