Spline sockets?

[kcmap]

So I picked up these today, MAC tool SC90 and SC91 Spline sockets. I've never seen one of these. Google says Audi and VW stuff has bolts that require these. Any and all thoughts?? Thanks.

 

[CJM8515]

triple square, commonly used on euro cars like vw/audi, benz, bmw, etc

 

[UserNameAttempt3]

Sometimes the wheel bolts use these.

 

[Toold_up]

Internal spline fastener heads sound like a bad idea for anything that is exposed to water or dirt...

 

[Kasal]

If I'm not mistaken they are XZN, I found them on some Volkswagen cylinder head.

 

[cvairwerks]

Triple squares and 12 point don't share the same point angle. Triples use 90 degree angles and 12 point use 30 degree. You can get away with using them sometimes, but not always.

 

[KnurledNut]

So I picked up these today, MAC tool SC90 and SC91 Spline sockets. I've never seen one of these. Google says Audi and VW stuff has bolts that require these. Any and all thoughts?? Thanks.

Some time ago, I went down a rabbit hole and did a research project of all the special application Mac SC sockets. They made a lot of them and some for only a short duration. There is no comprehensive list anywhere, so I made my own.
Those two sockets are 1/2" drive 12-point spline and were originally intended for use on Opel head bolts.

 

[scooby074]

VW head bolts for one use. I have one in my box

 

[kcmap]

Some time ago, I went down a rabbit hole and did a research project of all the special application Mac SC sockets. They made a lot of them and some for only a short duration. There is no comprehensive list anywhere, so I made my own.
Those two sockets are 1/2" drive 12-point spline and were originally intended for use on Opel head bolts.

Thanks for the info. Is it possible that SC list is available?? Only owned Chevy, GMC, Honda and Volvos... Really appreciate your knowlwdge.

 

[Jack Ryan]

I think this is a topic that always requires an explanation of context, otherwise it is ambiguous and the conversation goes in circles.

Spline is often a general description.

What is often called spline, is actually triple square - also called ZXN. It has 12 points with each point being 90 degrees as it is based on a square.



Another spline type tool is the double hex, this also has 12 points but the angle is greater. It fits but is incompatible with ZXN.



Another spline tool is the actual spline where the teeth are more rectangular. These are often made to be universal tools.



Jack