ISO 11446 (13-Pin) vs. Tow Ball Sizes
Comparing 2 standards across 13 specifications. 13 key differences identified.
The ISO 11446 Connector (also known as the Jaeger 13-Pin European standard) is the modern mandatory trailer electrical interface across Europe, the UK, and Australia. Featuring an IP-sealed, waterproof bayonet twist-locking circular housing with 13 gold-plated pin contacts supporting individual left/right lighting circuits, rear fog lamps, reverse lights, and continuous/switched caravan power.
Trailer Tow Balls (standardized globally under ISO 1103 for the 50.0 mm metric standard, and under SAE J684 for North American imperial sizes: 1-7/8", 2.0", 2-5/16", and 3.0") provide the spherical articulated mechanical pivot point between the towing vehicle and trailer coupler.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standardization
|
ISO 11446-1 / DIN ISO 11446 (Jaeger 13-Pole System) | — |
|
Mechanical Bayonet Lock
|
90-degree twist-to-lock bayonet collar with double silicone perimeter gasket (fully waterproof IP67) | — |
|
Pin 1 & 4 (Indicators)
|
Pin 1: Left Indicator (Yellow) | Pin 4: Right Indicator (Green) | — |
|
Pin 2 & 8 (Fog & Reverse)
|
Pin 2: Rear Fog Lamp (Blue) | Pin 8: Reversing Lights (Pink) | — |
|
Pin 3, 11, 13 (Independent Grounds)
|
Pin 3: Ground for Pins 1-8 | Pin 11: Ground for Pin 10 | Pin 13: Ground for Pin 9 (isolated 2.5 mm² ground returns) | — |
|
Pin 5 & 7 (Isolated Left/Right Tail)
|
Pin 5: Right Side Marker/Tail (Brown) | Pin 7: Left Side Marker/Tail (Black — separate fuses prevent total blackout if one side fails) | — |
|
Pin 9 & 10 (Caravan Power)
|
Pin 9: Permanent +12V unswitched battery feed (Orange) | Pin 10: Switched ignition +12V for caravan 3-way absorption refrigerator (Grey) | — |
|
ISO 1103 / European Standard
|
— | 50.0 mm (+0.0 / -0.4 mm) diameter spherical ball (ECE R55 standard; mandatory across Europe, UK, Australia, New Zealand) |
|
1-7/8 Inch (47.6 mm)
|
— | Light utility trailers, jet ski trailers, small rowboats (Class I hitches, rated up to 2,000–3,500 lb GTWR) |
|
2.0 Inch (50.8 mm)
|
— | The standard North American tow ball: travel trailers, midsize boats, car haulers (Class III hitches, rated up to 6,000–8,000 lb) |
|
2-5/16 Inch (58.7 mm)
|
— | Heavy travel trailers, 3-horse trailers, equipment flatbeds, commercial dump trailers (Class IV/V hitches, rated 10,000 to 20,000 lb) |
|
3.0 Inch (76.2 mm)
|
— | Severe gooseneck and heavy commercial industrial trailers (rated up to 30,000 lb+) |
|
Critical Mismatch Warning
|
— | A 50.0 mm European ball is 0.8 mm smaller than a 2.0" (50.8 mm) ball; coupling an imperial 2" trailer onto a 50mm ball can pop off under road dips |