On 28/11/19 12:39 pm, Clare Snyder wrote:
On Wed, 27 Nov 2019 10:54:18 -0800 (PST), wrote:

I had this question too in the middle of working on a car. That is when I discovered the following:
5mm = 3/16
8mm = 5/16
11mm = 7/16
14mm = 9/16
(starting to see the pattern?)

Manufacturers are not including the metric sizes which match up to common SAE sizes, either because the set purchased includes both metric and SAE or in order to encourage metric users to also purchase the SAE set given that there are more metric sizes than SAE.
Not true
At all.
The reason certain metric sizes are not included in most common tool
sets is different countries use different metric standards which use
different bolt head sizes.
Japanese cars do not use 11 or 13mm heads - they use 10 and 12 - and
14 for 6, 8, and 10mm bolts.
There are 3 main standards - ANSI/ISO, DIN, and JIS

All 3 use 7mm heads on 4mm and 8mm on 5 mm threads.
All 3 use 10mm heads on 6mm, and DIN only uses 11mm heads on 7mm
bolts.The other 2 standards do noy use any 7mm bolts.
On 8mm bolts JIS uses 12mm heads while DIN and ANSI?ISO use 13mm.
On 10mm bolts JIS uses 14mm, ANSI/ISO uses 16 and DIN uses 17mm.
On 14mm JIS uses 19, ANSI/ISO uses 21 and DIN uses 22
On 16mm JIS uses 22 while ANSI/ISO and DIN use 24
Only DIN uses 18mm with a 27mm head while ANSI/ISO and JIS use 20mm
threads with a 30mm head.
Then there are some manufacturers who go it alone and put a 11 mm
heads on a 6mm bolt.

SO for a german car you will get a set with 7,8,10,11,13,17,22,24 and
27mm.
On a Japanese set you get 7, 8, 10, 12, 14, 19, 22, and 30mm
On American metrics you use 7, 8, 10 (or sometimes 11), 13, 16, 21,
24, and 30mm

More or less.

I was going to mention that *difference* between Euro and Japanese but
you beat me to it! Comprehensively so too! ;-)

--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)