Automotive Blade Fuses
Electrical & Ignition Standards · 8 specs
Direct Answer
Automotive blade fuses protect 12V/24V/48V vehicle electrical circuits, standardized under ISO 8820-3 / SAE J1284 into six physical form factors (Micro2, Micro3, Mini, Low-Profile Mini, Regular ATO/ATC, and Maxi) using universal color-coded amperage ratings from 1A to 80A.
Source: ISO 8820-3:2015 Road Vehicles — Fuse-Links / SAE J1284 / SAE J2077 · Last reviewed Aug 28, 2026
Specs
| Governing Standards | ISO 8820-3 / SAE J1284 (Blade Type) / SAE J2077 (Miniature) |
| Micro2 Fuse (Dual-Blade) | 9.1 × 3.8 × 15.3 mm | 5A to 30A | Modern tight packaging standard |
| Micro3 Fuse (Three-Blade) | 14.4 × 3.8 × 18.0 mm | Dual circuits sharing one center power terminal |
| Mini Fuse (ATM / APM) | 10.9 × 3.6 × 16.3 mm | 2A to 30A | Common in 1990s–2010s vehicles |
| Low-Profile Mini (APS / ATT) | 10.9 × 3.8 × 8.7 mm | Ultra-short tabs flush with plastic housing |
| Regular Fuse (ATO / ATC / APR) | 19.1 × 5.1 × 18.5 mm | 1A to 40A | Universal benchmark standard |
| Maxi Fuse (APX / MAX) | 29.2 × 8.5 × 34.3 mm | 20A to 80A | High-current under-hood primary feeds |
| Standard Operating Voltage | 32V DC (Standard 12V/24V) / 58V DC (Specialty hybrid/48V mild hybrid) |
Standard Universal Blade Fuse Color Code & Amperage Matrix
| Color Designation | Amperage Rating (Amps) | Micro2 / Mini / LP Mini | Regular ATO / ATC | Maxi Fuse |
|---|---|---|---|---|
| Black | 1.0 A | — | ATO 1A | — |
| Gray | 2.0 A | Mini 2A | ATO 2A | — |
| Violet / Purple | 3.0 A | Micro2 / Mini 3A | ATO 3A | — |
| Pink | 4.0 A | Mini 4A | ATO 4A | — |
| Tan | 5.0 A | Micro2 / Mini 5A | ATO 5A | — |
| Brown | 7.5 A | Micro2 / Mini 7.5A | ATO 7.5A | — |
| Red | 10.0 A | Micro2 / Mini 10A | ATO / ATC 10A | — |
| Blue | 15.0 A | Micro2 / Mini 15A | ATO / ATC 15A | — |
| Yellow | 20.0 A | Micro2 / Mini 20A | ATO / ATC 20A | Maxi 20A (Yellow) |
| Clear / Natural | 25.0 A | Micro2 / Mini 25A | ATO / ATC 25A | Maxi 25A (Clear) |
| Green | 30.0 A | Micro2 / Mini 30A | ATO / ATC 30A | Maxi 30A (Green) |
| Blue-Green / Amber | 35.0 A | — | ATO 35A | Maxi 35A (Brown) |
| Orange | 40.0 A | — | ATO / ATC 40A | Maxi 40A (Orange) |
| Red | 50.0 A | — | — | Maxi 50A (Red) |
| Blue | 60.0 A | — | — | Maxi 60A (Blue) |
| Amber / Tan | 70.0 A | — | — | Maxi 70A (Tan) |
| Clear / White | 80.0 A | — | — | Maxi 80A (Clear) |
ATO vs ATC Fuses & Marine SAE J1171 Ignition Protection
While ATO and ATC blade fuses share identical exterior physical dimensions (19.1 × 5.1 × 18.5 mm), their environmental housings differ fundamentally:
- ATO (Open Element): ATO fuses have an open bottom slit where the fuse element is exposed to ambient air. In marine engine compartments or fuel-vapor environments, an open spark during a high-amperage blowout can ignite atmospheric gasoline vapors.
- ATC (Closed / Sealed Element): ATC fuses feature a fully ultrasonically sealed plastic body conforming to SAE J1171 External Ignition Protection, trapping any arc flash inside the polymer housing.