1 Jul
2019
1 Jul
'19
3:11 p.m.
Oh, but we are proud of our unremembered heritage, and
fiercely resist
change. We still use Fahrenheit. And efforts to "go metric" have made
little headway.
On Mon, 1 Jul 2019, dwight wrote:
Not every thing makes sense to go metric. Clearly bold
sizes are better
off in fractional sizes. Also for wrenches. I have to have 13, 14 and 15
mm wrenches. A 9/16 would have covered the entire range. I have a spot
on my car that I need a 23mm offset box wrench. What a pain.
I find that an SAE set of wrenches and a metric set of wrenches tend to
need similar quantities.
German cars switched from 14mm to 13mm heads for 8mm bolts about 5
decades ago.
Japanese use 12mm heads on 8mm bolts, and 13mm and 15mm are rare on
Japanese cars.
Unless you are dealing with vintage stuff - 10,13,15,17,19 for German
cars; 10,12,14,17,19 for Japanese cars
16mm, 18mm seem rare. Whitworth is finally rare
Yes, once you get above an inch, sizes are less standardized.
9/16 doesn't cover everything. It could, if you provided appropriate
punishment for any use of a 17/32 or 19/32 bolt head.
1/4-20 bolts use 7/16" heads, which is about 11mm. But lately, I have
encountered some 1/4-20 with 10mm heads! (Chinese specification change)