Double-ended ring spanner / box wrench: logical size progressions for set?

[Samuel D]

Assuming you don’t have a no-skip obsession – or even if you do – there may be a better way to go about this than making each spanner have two closely similar sizes.

For example, Toptul makes its AAEI range (75° deep-offset double-ended ring spanners) in the following sizes from 10–17 mm:
…
8×10
10×11
10×12
10×13
12×13
12×14
13×16
13×17
14×15
14×17
16×17
16×18
17×19
…

To cover the sizes 10, 12, 13, 14, 16, and 17 mm you could go with three spanners I’ll call Set A:

10×12
13×16
14×17

Or Set B:

10×13
12×14
16×17

And if these sets were incorporated into a larger set extending below 10 mm and above 17 mm, there would be additional permutations covering those six sizes.

Why would you choose Set A over Set B or vice-versa?

Are there any general rules for optimising the size progression, aside from application-specific reasons?

•••

Bonus question:

Eight of the spanners on this Toptul page have their model name preceded by •. For example, the AAEI1317 but not the AAEI1415. What does this bullet point mean?

 

[Samuel D]

Just a bump to catch another crowd. If there’s no interest I’ll let it slide after this. I realise it’s not the most important question in the world. Thanks for reading all the same.

 

[Junkdrawer Dog]

I would select set A if I was working mostly on Japanese cars. The 10 x 12 and 14 x 17 would cover a lot of ground with just 2 wrenches. If I was working on my own car(s), FIAT based, I would choose set B as I have not yet found any 12 or 14 mm required. I understand your point. I went through the same process selecting a set of open end SAE wrenches for the kitchen junk drawer. Trying to cover the most ground with the fewest wrenches.

 

[JR 42]

I'd probably choose door A, because both of my cars are Japanese makes like Junkdrawer Dog mentioned, and you get longer wrenches.

I always err on the side of too many wrenches, though, and would just buy a full set spaced by twos (8x10, 12x14, 13x15, 16x18, 17x19)... but I really like wrenches.

 

[Dave455]

If you’re going to go down the route of not having consecutive sizes, then the only sensible way to do it would be to make wrenches that allow you to put together specific sets for specific standards.

For example, somebody who works on a Japanese vehicles will need the JIS sizes of 8/10/12/14 etc, but never a 13

For German DIN you will need 7/8/10/13/17 etc, for ISO 7/8/13/16 etc and so on.

Personally, working on a variety of stuff, I find anything other than consecutive sizes almost impossible to work with, though I’d be happy to omit things like 9’s that I never encounter!

 

[Junkdrawer Dog]

Not a professional auto mechanic here, but I have never used a 9, 11, 15, or 18.

 

[richfinn]

Not a professional auto mechanic here, but I have never used a 9, 11, 15, or 18.

All those sizes are fairly common on European vehicles

9 and 11mm are common brake line and bleed screw sizes

15 and 18mm are regularly used on Ford suspension bolts 15mm is also used for serpentine belt tensioners

 

[richfinn]

Assuming you don’t have a no-skip obsession – or even if you do – there may be a better way to go about this than making each spanner have two closely similar sizes.

For example, Toptul makes its AAEI range (75° deep-offset double-ended ring spanners) in the following sizes from 10–17 mm:
…
8×10
10×11
10×12
10×13
12×13
12×14
13×16
13×17
14×15
14×17
16×17
16×18
17×19
…

To cover the sizes 10, 12, 13, 14, 16, and 17 mm you could go with three spanners I’ll call Set A:

10×12
13×16
14×17

Or Set B:

10×13
12×14
16×17

And if these sets were incorporated into a larger set extending below 10 mm and above 17 mm, there would be additional permutations covering those six sizes.

Why would you choose Set A over Set B or vice-versa?

Are there any general rules for optimising the size progression, aside from application-specific reasons?

•••

Bonus question:

Eight of the spanners on this Toptul page have their model name preceded by •. For example, the AAEI1317 but not the AAEI1415. What does this bullet point mean?

Set B for me

I use 10 and 13mm the most on Euro cars

12 and 14mm on Japanese cars

I would prefer 17 and 19mm for the largest sizes

 

[Samuel D]

Thanks for your thoughts, all. Good point about considering the length differences.

Any idea what the bullet point means before some of the spanner models on this page?

https://www.toptul.com/en/product-3...-75°-Offset-METRIC-Satin-Chrome-Finished.html

Seems like they’re ones with a wide spread, e.g. the AAEI1013.

 

[JR 42]

Been looking at that today while distracted by a toddler, and can't find a pattern. Looks like the satin 45 and 75 degree offset wrenches in satin finish in SAE and metric have dots in front of some part numbers/ size combinations... but the dots don't correlate to being available or not in mirror polish, or in sets, or match between the two wrench offset types in the same sizes...

 

[Samuel D]

Toptul replied to my question about the meaning of • before the model name. It just means that those models will be discontinued after stock runs out.

 

[Black300zx]

I would ask yourself three questions;
What sizes do you work on most?
Are you good enough to grab the correct size first try, or are you often 1mm off?
Do you work on vehicles which have mixed head sizes for the same thread size?

How you answer those questions will point you in the right direction. For me, I'd have 2 considerations:
1 - my truck has had a number of locations with m8 threaded fasteners with both 13mm and 15mm head sizes. For me, a 13/15mm combo would work well

2 - I often grab a 10mm wrench for an 11mm hex bolt (although i'm starting to learn what's what on my truck), so a 10/11mm combo would also make sense to avoid going back to the toolbox