XZN Set 11 Piece

Why is it called XZN? 

Is XZN the same as a spline drive?

What are triple square used for? 

XZN (also called triple square) refers to a specific type of 12-point drive system commonly used on European vehicles (e.g., Volkswagen, Audi, BMW, Mercedes, Porsche) for high-torque applications like cylinder head bolts, CV joints, and drivetrain components.However, not all 12-point styles are the same—there are distinct variations in the design of 12-point fasteners and tools, even though they all have 12 engagement points. The key differences lie in the angle of the points and the overall profile:1. Standard 12-Point (Double Hex or Bi-Hex)This is the most common 12-point socket style found in general tool sets.

It features a double-hexagon shape with 120-degree angles on the points (similar to a standard 6-point hex but doubled for more engagement positions).

Used primarily for 12-point bolt heads (common in aerospace, automotive performance parts like ARP bolts, or some engine applications) or as a versatile alternative to 6-point sockets on hex bolts.

Advantages: Easier to align in tight spaces (only needs 30-degree rotation to engage), can fit hex (6-point) bolts, square bolts in a pinch, or true 12-point external bolt heads.Not interchangeable with XZN in high-torque scenarios without risk of slipping or damage.

2. XZN (Triple Square)A specialized 12-point internal drive (usually male bits for female fastener recesses).

Features 90-degree angles on the points, created by overlaying three squares (hence "triple square").

Designed for very high torque without stripping, common in German/European cars.Not the same as standard 12-point—a regular 12-point socket or bit will often fit loosely or slip on XZN fasteners, and vice versa can damage the tool or bolt.

3. Spline Drive (12-Spline Flange or Multi-Spline)Another 12-point-like system, but with more rounded or splined teeth (often many more than 12, but some variants are called 12-point spline).

Distinct from both above; has a different tooth profile (more like fine splines on a shaft). Used in some automotive or industrial applications for even torque distribution.

The pattern on the left (labeled "TRIPLE SQUARE" with the 90° angle) is the XZN (triple square). Here's why, based on the diagram and standard tool specifications: XZN/triple square features sharper points with 90-degree internal angles (created by overlaying three squares), resulting in deeper, more pronounced grooves and a star-like appearance. This design allows for higher torque transfer without slipping, which is why it's common on many European car fasteners.

The pattern on the right (labeled "12 POINT" with the 120° angle) is the standard double-hex (or bi-hex) 12-point style, with wider, more rounded points (essentially two overlaid hexagons). It's more versatile for general use but provides less grip under extreme torque.

They are not interchangeable on high-torque bolts—using a standard 12-point tool on an XZN fastener (or vice versa) risks rounding or stripping.

In summary, while XZN is a 12-point style, it is not interchangeable with standard 12-point (double hex) tools due to the angle difference (90° vs. 120°). Using the wrong one on high-torque fasteners can lead to rounding or stripping. If you're working on European cars, dedicated XZN/triple square bits are essential. For general use, standard 12-point sockets are more versatile but less grippy than 6-point on hex fasteners.