Side-by-Side Comparison
Towing & Hitches
ISO 1724 (7-Pin) vs. Tow Ball Sizes
Comparing 2 standards across 14 specifications. 14 key differences identified.
Comparing:
ISO 1724 (7-Pin)
Tow Ball Sizes
The ISO 1724 Connector (commonly known as the European Type 12N 7-Pin plug) is the classical European standard for basic trailer lighting. Featuring a circular 7-pin metal or plastic housing with split brass pins, it provides the essential exterior road lighting circuits (left/right turn, isolated left/right tail lights, brake lights, and rear fog lamp).
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
14 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standardization
|
ISO 1724 / DIN 72577 (Type 12N–Normal) | — |
|
Pin 1 (Yellow–Terminal L)
|
Left Hand Direction Indicator (Turn signal) | — |
|
Pin 2 (Blue–Terminal 54G)
|
Rear Fog Lamp (or +12V permanent feed on older caravans) | — |
|
Pin 3 (White–Terminal 31)
|
Common Chassis Ground Return | — |
|
Pin 4 (Green–Terminal R)
|
Right Hand Direction Indicator | — |
|
Pin 5 (Brown–Terminal 58R)
|
Right Hand Tail Light, Clearance Lights, and License Plate Lamp | — |
|
Pin 6 (Red–Terminal 54)
|
Brake / Stop Lights | — |
|
Pin 7 (Black–Terminal 58L)
|
Left Hand Tail Light and Left Hand Clearance Lights | — |
|
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 |