On 9/13/2016 7:53 AM, DerbyDad03 wrote:
On Monday, September 12, 2016 at 11:36:37 PM UTC-4, wrote:
On Mon, 12 Sep 2016 20:30:59 -0400, Ed Pawlowski wrote:

On 9/12/2016 8:21 PM, wrote:
A rusty 17mm nut may need the next size up wrench in order to be able to fit it, I've had this happen, its not bad idea to have those odd size wrenches


How often has it happened? Started using metric tools about 1970 and
have not needed one yet so I see no reason to buy a tool I don't ever
need. Use an adjustable or pipe wrench once every 10 years that you
need it. Be sure to get a metric adjustable .
There are at leat 3 metric "standards" and each uses a few different
sized bolts, and different head sizes You have the German DIN system,
the Japanese SI and the American ANSI/ASME

The SI is actually common pretty much world wide except America and
Germany - there are exceptions.

Depending on the market you may get 10mm and not 11, you may or may
not get either 12 or 13mm, and 17 or 18mm - and some get 15, others do
not.

I've worked on vehicles using every one of them (not all on the same
vehicle) - I'd have been totally lost without a minimum of 8, 10, 12,
13, 14, 15, 17, 18. 19, and 21 mm
On Toyotas the 11 and 13 and 18 were not required - on American iron
the 10 and 12 are pretty much redundant - along with the 17, I
believe.

What does "the 10 and 12 are pretty much redundant" mean?

How does "redundant" apply in that context?



I'm guessing he means "common".

I've often been able to use one of the standard sizes in place of the
less common metric sizes such as 18mm. Otherwise, an adjustable wrench
has saved me, though, in some tight spots, it's not always the answer.
Overall, I nice ratchet/socket set with all sizes usually suffices.