At 08:52 AM 12/24/2014, Dennis Haynes wrote:
>Currently I have a few young folks that are interested in learning
>to work on cars. As part of my knowledge sharing I am working get
>them to recognize hardware by the size of the threads, not wrenches.
>Those screws on the drums are 7mm and yes they have an 11mm hex. I
>think they are they only 7mm screws on out vans from the factory.
>For most small DIN fasteners the head is thread size + 50% +up to
>the next size. For the large stuff add 50%.

Hi Dennis,

Could I suggest a slight refinement?  Get them used to saying "M8" or
even "M8x1.25" or "M8x1".  Even work up to "M8x1.25, 24mm, class
10.9" where it makes sense.  That would change to "JIS8" ("ISO8"?)
for Toyotas where the 8 mm bolt takes a 12 mm wrench.

Merry Christmas,
d