Fuse Specifications
In electronics and electrical engineering, fuses are used to prevent an overcurrent condition from damaging the circuit that it is designed to protect. Fuses come in many shapes, sizes, current limits, and operational voltages. The primary component in the fuse it usually a metal wire whose length, diameter, and alloy composition is tailored to melt (fuse) at a precise current value.
Two basic types of fuses are available - fast reaction and slow reaction. Fast reaction fuses are used to protect circuit that cannot tolerate even a small amount of excessive current. The sensitive gate of a semiconductor device is an example. Slow reaction (slow-blow) fuses are used for circuits where a higher than normal current condition can be survived for a short time, such as a motor when it first starts (inrush current can be many times greater than the normal run current).
Fuse drawing page Fuse vendor page
In addition to the sizes represented here, surface mount (SMT) packages are available in standard outlines beginning as small as 0603 (0.063" x 0.031"). See Fuse vendor listing.
Two basic types of fuses are available - fast reaction and slow reaction. Fast reaction fuses are used to protect circuit that cannot tolerate even a small amount of excessive current. The sensitive gate of a semiconductor device is an example. Slow reaction (slow-blow) fuses are used for circuits where a higher than normal current condition can be survived for a short time, such as a motor when it first starts (inrush current can be many times greater than the normal run current).
Fuse drawing page Fuse vendor page
In addition to the sizes represented here, surface mount (SMT) packages are available in standard outlines beginning as small as 0603 (0.063" x 0.031"). See Fuse vendor listing.
| Size | Diameter (in.) | Length (in.) | Standard Voltages (V) | Standard Currents (A) |
| 1AG (AGA) glass | 1/4 | 5/8 | 125 32 | 1/16,1/10,1/8,1/4 3/8,1/2,6/10,3/4,1 1-1/2,2,2-1/2,3,5 6,7,7-1/2,10,15, 20,25,30 |
| 2AG (225) glass | 0.177 | 0.588 | 250 125 | 1/10,1/8,1/4,3/8 1/2,3/4,1,1-1/2,2 2-1/2,3,3-1/2 4,5,6,7,8,10 |
| 3AG (AGC) glass | 1/4 | 1-1/4 | 250 32 | 1/20,1/16,1/10,1/8,3/16 2/10,1/4,3/10,3/8,1/2,3/4 1,1-1/4,1-1/2,2,2-1/4 2-1/2,3,4,5,6,7,8,9,10 15,20,25,30 |
| 3AB (ABC) ceramic | 1/4 | 1-1/4 | 250 125 | 1/8,1/4,1/2,3/4,1,2 3,4,5,6,7,8,10,12 15,20 25,30 |
| 4AG (AG) | 9/32 | 1-1/4 | ||
| 5AG (AGU) glass | 13/32 | 1-1/2 | 250 32 | 1,2,3 4,5,8,10,15,20,25 30,35,40,50,60 |
| 7AG (AGW) glass | 1/4 | 7/8 | 32 | 1,1-1/2,2,2-1/2,3 4,5,6,7-1/2,10,15 20,25,30 |
| 8AG (AGX) glass | 1/4 | 1 | 250 125 32 | 1/500,1/200/1/100 1/32,1/16,1/10,1/8 2/10,3/16,1/4,3/10 3/8,4/10,1/2,3/4,1 1-1/4,1-1/2,22-1/2,3,4,5,6,7 8,10,15,20,25,30 |
| 5x15mm (C519,C520) glass | 5 mm | 15 mm | 250 125 | 125mA,250mA,350mA 375mA,500mA,600mA 750mA,1,1.25,1.5,1.62,2.5,3,3.5,4,5 |
| 5x20mm (GDA,GDB) glass | 5 mm | 20 mm | 250 | 50mA,63mA,80mA,100mA 125mA,160mA,200mA 250mA,315mA,400mA,500mA 630mA,800mA,1,1.25,1.6 2,2.5,3.15,4,5,6.3,8,10 |
| Nanofuse | 0.080 | 0.225 | 125 60 32 | 1/16,1/8,1/4 3/8,1/2 3/4,1,1-1/2,2 2-1/2,3,3-1/2,4 5,7,10,12,15 |
| SFE | 1/4 | 5/8 to 1-7/16 | ||
| Automotive (ATC) blade | 0.207 (W) 0.752 (H) | 0.760 | 32 | Black = 1A Gray = 2A Violet = 3A Pink = 4A Tan = 5A Brown = 7½ Red = 10A Blue = 15A Yellow = 20A Clear = 25A Green = 30A Amber = 40A |
| Mini Auto (ATM) blade | 0.15 (W) 0.429 (H) | 0.760 | 32 | Gray = 2A Violet = 3A Pink = 4A Tan = 5A Brown = 7½ Red = 10A Blue = 15A Yellow = 20A Clear = 25A Green = 30A |
Note: The "AG" term comes from Automobile Glass fuse. | ||||
| Current Rating/Derating | ||
| Specify fuse current as: Nominal Operating Current / 0.75, at 25ºC, then derate fuse current above or below 25°C per chart. | ||
| Derating: | A = Slow Blow B = Fast C = Resettable |  |