Metric socket head cap screws have a slightly higher yield than the grade 12.9 screws per Bossard.

Steve

On May 2, 2013, at 12:10 PM, Ed wrote:

> Jeff,
> Steve is correct.
> 
> If the originals are cap screws, they should be replaced with like strength
> cap screws.  Manufactures watch costs and they don't use stronger (and more
> expensive) bolts unless they are needed.
> 
> Also, look up the difference between metric Class and SAE Grade for bolt
> strength.  This information will help prevent expensive and inconvenient
> breakdowns.
> 
> If metric bolts are cap screws they are probably Class 12.9 and that will be
> written on the top of the head around the edge.  Check to make sure before
> you buy.  ETKA shows these to be M12X1.5x20 allen key head bolts.  Be sure
> to torque them correctly, which means dry unless indicated different in a
> factory (i.e. Bentley) manual.  Make sure the heads of the bolts are the
> same height as original.  It is possible, although I don't remember if it is
> a problem with the Vanagon, for the heads to hit the clutch disk hub if they
> are too tall.  Also, don't buy critical bolts from your local big box store,
> buy them from a reputable bolt supplier, either online or locally.  Most
> cities of significant size have a quality fastener store.  And also use
> quality washers if they were originally present.
> 
> Do this and you should be fine.
> 
> Ed