Metric Wrench Sizes???


Aug 23, 2006
Northwest, MO.
2005 Rocket III
Hey all, I have a question to pose to all of you knuckle busters but, as usual, must tell the terms behind the question first.

I was an auto mechanic in years prior to 1982 and would only purchase Snap-On, MAC (transitioned over to Matco I believe) & SK tools. These days my wrench turning is not my livelihood so I can be satisfied with the mediocre tool quality of Sears Craftsman brand. You gotta admit, if it fails, it's replaced & that's fine by me. I've even found screwdrivers in the street & took them to Sears for a replacement. You also gotta admit that the tool designers at Sears are always looking at innovative ways to approach tools, and do very well as one can see in the latest mailed catalog.

OK, the last repair to the Rocket was to replace the rear tire. Removal of the tire requires taking the rear brake caliper mounting bracket off which is really "put on" at the factory. I own a MAC metric combination wrench set but it's a 12 point set. The "really tight" caliper bracket bolt required some drastic measures to loosen. Such as, Step 1: put the box end on the bolt head, push with both feet and get no where. Wrench is too short for both feet and leverage is insufficient. Step two: put box end on bolt head, hold firm in the "loosen" direction and hit wrench with 8 lb. hammer. After a few gentle blows and working my way up to the "take that" blows, it breaks loose. Celebrate with a few cold swigs of the famous Hamm's beer & proceed with the disassembly. After the rear wheel is off the bike, I neatly arrange the tools and fasteners to prepare for reassembly when new tire is mounted. That's when I notice the deformation I inflected on the hex head of the caliper bracket capscrew. Concerned that the tightening of the bolt would finish rounding the hex off, I took a trip to Sears & purchased a 6 point wrench just for the occasion. Task complete, I asked myself what I was going to do with "1" 6 point wrench. I returned the wrench to Sears (still looking new) & started investigating the prospect of purchasing a "set" of 6 point wrenches. I found a pretty good deal in a Sears Craftsman Club flyer, 14 wrenches ranging from 6mm to 19mm, and a nice roll up tool pouch for $60.

Now, I have worked with metric wrenches periodically & know that some of these sizes will most likely never get "worn out" from over use, such as 9mm & 16mm but having the complete set is the only way to own wrenches, right? But, I know that I've used my 21mm six point, 3/8 drive MAC socket before (I didn't use the socket on the stubborn capscrew 'cause I would have had to remove the lower TOR's pipe, which was just installed a few weeks before, to have straight access) so the set with a 19mm wrench as the largest seem to fall short of an adequate purchase. More wrenches to finish off this set is the remedy for my dilemma.

Which brings us to the question at hand. Having sizes 6mm thru 19mm, what larger sizes are most practical? I am looking at purchasing 2 (maybe 3) additional wrenches to fill the pouch. I've taken this approach with the set so far, remove the 6 & 7mm wrenches from their "smallest" pockets in the pouch & move all the other wrenches "down" 2 slots. Insert the 6 & 7mm wrenches in with the 14 & 15mm wrenches (they fit nicely & will not slide down too far in the pocket as to disappear from sight). This leaves the 2 largest slots available for large wrenches. Would I ever use a 20mm wrench? Am I better off getting 21 & 22mm wrenches? Or do I go one step further and find room for the 6, 7 & 8mm wrenches as I've explained & get 20, 21 & 22mm wrenchs? :confused:

I'm hoping someone out there (and I expect Tomo to really assist in this unprecedented decision, sharing his expertise with me ) is able to provide guidance for the most practical choices.

Thanks guys.

See ya.

Oh yea, forgot to mention, when the wrench set arrived (internet purchase), all the wrenches were "thrown" loosely in a box, along with the pouch. As I filled the pouch the first time, I found that wrench sizes 6, 7 & 8 were missing. I had to contact Sears about the error & about 2 weeks later, my long lost wrenches arrived. All the other wrenches were smiling as I inserted the 3 smaller brothers in their place.
Rusty, that's complicated. I prefer the 'flank drive' stuff from Crap-on.... and, why the hell didn't you use an impact gun. I never do anything without my trusty IR. beating on an box wrench handle with a hammer is pretty crass.:D

If you don't have a compressor with it's beans, you can always get a 110V deWalt 1/;2" gun. Everybody, well almost everybody has electricity and various extension cords.

If you need a compressor I have a 30CFM @175PSI Intercooled and aftercooled unit for sale. That should fill your needs quite nicely.
OK, OK, OK! I only revert to "Primative Pete" therory when I feel it's necessary and all other practical approaches don't result in positive headway. I didn't have an impact socket and have already replaced 2 of the 3/8 drive metric ones due to excess force splitting the walls. Besides, I was avoiding removing the exhaust which I tend to scratch or otherwise scare during handling.

So, back the the "which wrench sizes" question!

After some sleep (last night) I have to add that I have metric wrenches up to 30mm. The reason why is that my Kubota's as well as John deere's are mostly metric. So are most stuff on cars these day. Probably the only size in a pure metric wrench I never use is 13mm which is 1/2" SAE. I prefer the flank drive. It won't round off the flats if the fit is a little sloppy.

Your post has given me a headache..Just get 3 of everything,thats what I do and still can't find what I need..Tomo would have the best way to go I'd bet..Where the hell Is he?? Craxy Jack Opps I use to be a Primative Pete too,until I got a hot wrench...Ha Will undo anything...
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Buy more tools, its like builiding a garage. Never big enough. My beemer had lots odd (3mm, 7mm, 9mm) fastners plus all sorts of torx, The more junk you have the more you'll find that those odd wrenches aint so odd. I buy several at a time so I can find at least one:D
Going from my feeble memory... Basically a standard metric wrench set is from 10 mm inclusive up to 19mm. Beyond that I have 20, 21, 22, 24, 27, and 30. You may find that the sizes I am missing aren't even available from Sears. Possibly a better way to make a decision would be to take a mic and measure the large fasteners on your Rocket and see what you really need to work on it. Sears isn't all that expensive for those large wrenches, probably in the $15 to $20 range each.