Flank Drive Questions

jacob_coulter · Oct 5, 2006

I just found this forum, and I love it!

I had a question about Snap-On's "Flank Drive" feature on there wrenches. What exactly is it? I've heard that this was a pattened feature they at one time owned, but the patent has expired and now most tool manufacturers use it. Is that true?

Thanks for the info

wilbilt · Oct 5, 2006

I have heard that the patent ran out. Regardless, the design is used by most manufaturers these days.

The shape of the box (or socket) broach is "relieved" via a radius at the corners. This causes the rotational force to be applied to the fastener a small distance from the actual corner of the fastener, thus reducing the tendency to "round" or "strip" the head of the fastener when loosening or tightening.

It might sound "gimmicky", but does seem to work well.

kartracer55 · Oct 5, 2006

Definetly. just about everysocket you buy... standard or imported will have some sort of corner relief on it. Keeps the force being applied to the flats rather than the corners, which can round out easily. Not a joke, its the norm. nowadays

Ign · Oct 8, 2006

Danaher just calls it "Surface Drive"

http://www.gearwrench.com/ratcheting_wrenches/combination/index.jsp

bmwpower · Oct 8, 2006

Yea but doesn't Snap-on have the flank drive on the OPEN end as well? Never seen that on another brand.

EdNJ · Oct 8, 2006

Do you mean Flank Drive Plus?

It's the serrations on the wrench flats,and it's not a gimmick. Matco sells something similar called Opti Torque or something.

eschoendorff · Oct 8, 2006

EdNJ said:
Do you mean Flank Drive Plus?

It's the serrations on the wrench flats,and it's not a gimmick. Matco sells something similar called Opti Torque or something.

No chit???? That open end actually works?

What is it that SO does so special that their open ends don't spread? I gotta believe that there are other brands that don't spread either - otherwise people wouldn't be buying them....

l_bilyk · Oct 8, 2006

I think those "flank drive" wrenches are no good... because if the wrench isnt on there perfectly than that raised region could be putting EXTRA pressure on the corner

wantedabiggergarage · Oct 9, 2006

The patent on the flank drive ran out, so now it is used by most decent tool companies. HOWEVER, the TRADEMARK on "Flank Drive" doesn't expire. That is why it is normally called something else.

As for the spread or lack there of, I can only speak from my observations, and what I have been told.
1. Snap~On's wrenchs, have a thicker head then some of the ones I have looked at.
2. I have been told (haven't been able to verify), that Snap~On uses both a higher quality steel, and doesn't use as much recycled steel (trying to control the contents/mixture ratio).

cc_rider · Oct 9, 2006

I've heard the same info 'wanted' heard as well. I don't have proof of it, but know a bit about steel and foundries. The cost of steel varies a LOT with its composition. Plus, depending on the grade of steel you specify, the mill may be required to conduct a tensile test on every batch, to verify mechanical performance. You can bet most tool mftrs are not gonna go to the extra expense of specifying their steel to that extent. All I know for sure is S-O tools are made of some pretty strong stuff. Which is not to say others are not; there are still a few high quality tool manufacturers which still care about quality.

c.

TNToy · Oct 12, 2006

EdNJ said:
It's the serrations on the wrench flats,and it's not a gimmick. Matco sells something similar called Opti Torque or something.

It's common on the box-end of wrenches and on impact sockets. Snap on, Mac, Matco, Cornwell... they've all got it.

On the open end, Snap-On's Flank Drive Plus and Matco's Opti-Torque are the only ones, as far as I know. The Matco version only works in one direction, though. If you have to bring the wrench in there 'backwards' to break a frozen fastener with the open end, it's just an ordinary wrench.

That said, they very much do work. I ocassionally service things like jam nuts on tie-rod ends that you HAVE to use an open-end wrench on, and they're frozen. We have a cheap mix of everyone's Gearwrench, Husky/Kobalt, and Craftsman wrenches lying on the alignment rack. When I've got a stubborn tie-rod, the jaws on the craftsman will spread and round-over to the next side of the hex. The Gearwrenches and HD/Lowes stuff are a little bit better, but if it's stuck, I grab a Snap-On or Matco wrench of the appropriate size out of my box and break the exact same fastener free pretty most of the time.

I don't have any flank-drive plus snap-on stuff yet, but I'm eyeing some. The guy in the bay next to me has about $350K worth of Snappy, and I've used his notched-jaw wrenches out of curiosity. They do seem to work a hair better.

Mostly, you're paying for good steel. And yeah, a jewelry-like finish too. Most wrenches (craftsman, etc) are a cast material that, when broken, looks like pot metal - it's very pourous and a dull, matte gray material. If you've ever snapped a snappy wrench or ratchet, it looks like it was machined out of a piece of bar-stock or something. No porosity and much shinier inside.

Personally, I'd rank the ones I've used this way:
Snap-On
Matco
SK
Gearwrench/similar
Cornwell
Craftsman
Pittsburgh/Harbor Freight/Pot Metal

Before you ask, if the high-dollar Snappy wrenches can't get a stuck tie-rod free, I go grab a $20 Rigid pipe wrench, and bust it loose that way. Home Depot to the rescue...

Coach James · Oct 12, 2006

Kobalt and Craftsman are both made by Danaher. I wonder how much different the material really is? Are you using the raised panel Craftsman or the Pro line?

The current Kobalt production looks exactly like Allen, another Danaher line.
Coach

TNToy · Oct 12, 2006

Coach James said:
Kobalt and Craftsman are both made by Danaher. I wonder how much different the material really is? Are you using the raised panel Craftsman or the Pro line?

I've used a little of the Kobalt stuff, and it's probably equivalent to Craftsman Pro. My remarks about craftsman above are directed at the raised panel sold-in-malls-everywhere stuff... since that's what 99% of people are referring to when they say 'Craftsman wrench".

Also, there's another company in the Danaher line I like a lot more. Matco is also made by Danaher... and a considerable leap in quality above Kobalt, Gearwrench, Craftsman, etc.

By the way: Matco's combination wrenches etc. are oftentimes actually slightly MORE expensive than Snap-On.

Since this topic brought it to my attention, I asked two of the other guys at work about Flank-Drive Plus (notches/ridges in open end) since I know they've got a set of them. They've both owned a set of standard Snap-On wrenches before, and they both want their old ones back. There are a lot of places you can't get a straight-on grip on a fastener with the open end, and in those cases the regualr Snappy works better, in their opinion.

By the way: Snap-On has a smooth-jawed version and the F.D. plus version of most of their wrench sets. So you DO have a choice.

eschoendorff · Oct 12, 2006

Coach James said:
Kobalt and Craftsman are both made by Danaher. I wonder how much different the material really is? Are you using the raised panel Craftsman or the Pro line?

The current Kobalt production looks exactly like Allen, another Danaher line.
Coach

Because they are. :thumbup:

ampegor · Oct 15, 2006

Proto makes a serreated style open end as well. i think it is called posi-torque or something like that. Have some at work and there is a difference
Andy

ndoran · Aug 11, 2011

TNToy said:
It's common on the box-end of wrenches and on impact sockets. Snap on, Mac, Matco, Cornwell... they've all got it.

On the open end, Snap-On's Flank Drive Plus and Matco's Opti-Torque are the only ones, as far as I know. The Matco version only works in one direction, though. If you have to bring the wrench in there 'backwards' to break a frozen fastener with the open end, it's just an ordinary wrench.

That said, they very much do work. I ocassionally service things like jam nuts on tie-rod ends that you HAVE to use an open-end wrench on, and they're frozen. We have a cheap mix of everyone's Gearwrench, Husky/Kobalt, and Craftsman wrenches lying on the alignment rack. When I've got a stubborn tie-rod, the jaws on the craftsman will spread and round-over to the next side of the hex. The Gearwrenches and HD/Lowes stuff are a little bit better, but if it's stuck, I grab a Snap-On or Matco wrench of the appropriate size out of my box and break the exact same fastener free pretty most of the time.

I don't have any flank-drive plus snap-on stuff yet, but I'm eyeing some. The guy in the bay next to me has about $350K worth of Snappy, and I've used his notched-jaw wrenches out of curiosity. They do seem to work a hair better.

Mostly, you're paying for good steel. And yeah, a jewelry-like finish too. Most wrenches (craftsman, etc) are a cast material that, when broken, looks like pot metal - it's very pourous and a dull, matte gray material. If you've ever snapped a snappy wrench or ratchet, it looks like it was machined out of a piece of bar-stock or something. No porosity and much shinier inside.

Personally, I'd rank the ones I've used this way:
Snap-On
Matco
SK
Gearwrench/similar
Cornwell
Craftsman
Pittsburgh/Harbor Freight/Pot Metal

Before you ask, if the high-dollar Snappy wrenches can't get a stuck tie-rod free, I go grab a $20 Rigid pipe wrench, and bust it loose that way. Home Depot to the rescue...

the visual appearance of steel after it is broken is not representative of the grain structure of steel that has not been stressed beyond its yield point. If you want to examine the grain structure before the metal yields the sample needs to be cross sectioned and then polishedon a lapping bench with increasingly finer polishing compounds and then visually examined at extremely high magnification levels.

Obie · Aug 11, 2011

Proto has what is called Anti Slip Design on the open ends. They are great quality wrenches, and can usually be found at a decent price regardless of new or used. Wright also makes wrenches that have the Wright Grip feature. This design has saved my *** quite a few times on badly mucked fasteners. They currently only offer it in standard. I have heard rumors and rumblings about them coming out with a metric line sometime in the future.

Does Armstrong have a version of this? I can't remember. There are a few other companies that offer the FD style open ends, but I can't think of them at the moment.

strikeouttruck · Aug 11, 2011

Get the flank drive plus and be done with it. I have gear wrench, blue point, craftsman, matco and snap on wrenches in my box and let me tell you the second anything looks gummed up or that it might remotly round i reach for the flank drive plus and have yet to be let down. The other wrenches just get used for various special duty (blue point flex ratcheting, craftsman for cutting and welding, matco for 6 point).

Obie · Aug 11, 2011

Oh jeez, I forgot about the Williams SuperCombos, haha, and I even have a few. Think its time for me to hit the hay.

bart1 · Nov 17, 2011

Late add here, but Wright Grips also have a serrated open end.

MoToys · Nov 17, 2011

I might be restating something that was already said but there is a difference between Flank drive and Flank drive plus.
Regular flank drive is noticeable and used in sockets and the flank drive plus is only seen on wrenches.

Fordman7795 · Nov 17, 2011

Didnt see it mentioned while scanning the thread but Mac calls theirs Knuckle Saver

Heavy Metal Doctor · Nov 17, 2011

All I can add is that I have a FDP set of wrenches I have used nearly every working day since I started in 95 and they DO work - I have found I will snap off the bolt before it rounds the head off. :thumbup:

Obie · Nov 17, 2011

Armstrong does have a notched open end as well, at least on some of their wrenches. I recently aquired a set of the metric Maxx Beam (Crossforce) with the notched open ends, very nice wrenches. Longer than my Wrights too, so I use them when I really need to put some force down.

FergusonTO35 · Nov 17, 2011

When I did alignments I prefered the Matco Opti-Torque wrenches. They worked really well and didn't chew up the hex.

jjvaldez1984 · Dec 6, 2011

What about the mac tools i beam precision torque wrenches anybody have some of those or has seen them? IF so i wanna see apic of the open end

e30bradley · Mar 29, 2012

TNToy said:
Since this topic brought it to my attention, I asked two of the other guys at work about Flank-Drive Plus (notches/ridges in open end) since I know they've got a set of them. They've both owned a set of standard Snap-On wrenches before, and they both want their old ones back. There are a lot of places you can't get a straight-on grip on a fastener with the open end, and in those cases the regualr Snappy works better, in their opinion.

F&%@!!!!!! I wish I read this last week.. I just bought a set of flank drive plus wrenches from 10-19mm.. I guess once I use them some more I'll make my own opinion on them.. So if the wrench isn't perfectly on the bolt it won't work at all? Like the wrench won't grab? and can explain what you mean by perfectly on? you mean the jaws of the wrench perfectly parallel to the flats on the bolt and pressed all the way against the back of the open end of the wrench?..

binder man · Mar 29, 2012

No. You can actually use a FDP with the open end BARELY on a a nut and it will still break it loose. Love them especially for quick use of the open end just get the tips on the nut and spin away with no worries.

Buckgnarly · Mar 29, 2012

binder man said:
No. You can actually use a FDP with the open end BARELY on a a nut and it will still break it loose. Love them especially for quick use of the open end just get the tips on the nut and spin away with no worries.

Agreed. I gotta admit, after getting my sets of FD+, I can't imagine an open end that grabs better, and there is no need ot be in a "special" position. they really are worth it when an open end is needed on rusted/stuck ****...and I know there is no shortage of rusted **** up here!

Ratchet. · Mar 29, 2012

Buckgnarly said:
Agreed. I gotta admit, after getting my sets of FD+, I can't imagine an open end that grabs better, and there is no need ot be in a "special" position. they really are worth it when an open end is needed on rusted/stuck ****...and I know there is no shortage of rusted **** up here!

Same, I've had my set almost 10 years (maybe a bit less, wasn't that long after they came out iirc) and there the most used set of wrenches i own, if they wont shift a bolt you most likely will need to heat it... (trackrods etc when you cant use the ring end or a socket) and living in the uk near the coast see a lot of rusty bolts

Only downside to them (if you could call it that) is they mark bolts, so if your wrenching on your motorcycle or classic /modified car and don't want to damage the surface of the fasteners use a plain set of spanners

Wakefield · Mar 29, 2012

Any open end wrench should be least apt to be strained if the nut is all of the way into the mouth of the wrench.
Any contests between Wright Grips and Snap On Flank Drive + ? Is one less apt to mark the nut/bolt head?

Edit- Loc-Rite as found on old Kelsey-Hayes and Bonney 12 points seems to be the ancestor of Flank Drive type wrench openings. As early as 1964 according to Alloy Artifacts---- Did it provide an advantage over the traditional sharp cornered 12 point?

DrkMtnDew · Mar 29, 2012

The FDP ends really grab onto a fastener and don't let go. I also have a set of Proto and GearWrench with the notched open ends they work really well too but they aren't as good as FDP. Only downside I can see to the FDP is that they bite so hard that it kinda deforms the nut or bolt that's being removed.

Murphy4570 · Mar 29, 2012

Flank Drive Plus is the cat's meow. Seriously. You will never round off a bolt head again. The way the teeth are designed, you can get a lot of leverage with only half of the open end on a bolt head. Locks in there and holds on tight. Great wrenches, I have a few.

I also have Snap-On's ratcheting combo wrenches with FDP open ends. Only ratcheting combination wrench that has an open end that's worth a damn. They cost a damn mint though, somewhere around $400. Snappy doesn't include 8 or 9mm in the set, I had to buy those separately.

http://buy1.snapon.com/catalog/item...roup_ID=681628&store=snapon-store&dir=catalog

Xavis00 · Mar 30, 2012

The other day, I was taking a running board off a early 90s Tahoe, and even my Flank Drive Snap-On sockets couldn't get a grip since the bolts were so rounded. Pulled out my FDP wrenches, turned them off no problem. I knew in the back of my head that they were worth the extra money when I got them, but that little incident made every penny worth it. They will mark up bolts though (In the catalouge, SO recommends using a standard open end on bolts that shouldn't be marked be marked), so having a cheapy set of non-FDP is nice if you have to use an open end and not mark up a painted/chrome/whatever bolt.

countryroad82 · Mar 30, 2012

The FD+ is what sold me on Snap On. I bought a set when my dealer took my Craftsman 7/16, clamped a 7/16 bar stock in a vise, proceded to let me round it with my wrench, handed me a 7/16 FD+ and I hung on it like a monkey before I made it slip. I bought a set that day and haven't looked back.

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