Torque on the backside phillips

[Lynn LeFey]

I was testing a POS swiss army knife knockoff the other day, and decided I was going to run test-to-fail. I used its backside phillips on a wood screw in a bench I put together (screw-and-glue). Of course, it torqued the driver so bad it nearly pulled the knife apart. 'Hah!', I thought.

Then I decided I had to be fair and subject my Tinker to the same test. It seemed like there was either maybe a hair of stretching of the pin holding the backside tools together or the pin was pulling out of the piece its peened into. In any case, I was a little shocked. I THOUGHT the backside phillips should have been able to handle the torque I was applying.

Am I just expecting too much of the tool?

[gustophersmob]

As seen in this thread with a OHT, it appears the back-side philips is not made to handle much torque. A shame, really, on an otherwise solid tool.

So, I wouldn't expect too much out of them, sadly. 

[Lynn LeFey]

Well... there you go. Mr. Whippy beat me to it. I'd guess it seemed like about 20 to 30 lbs of force I was applying.

The same problem was not apparent in any Leatherman tool, or the Vic Spirit, or even the beefier knock-off plier based MTs (like the Kobalt).

I will say I didn't go so far as ripping the phillips out of the tool. Kudos to Mr. W for doing a more thorough test.

Still... I'm a bit disappointed.

[gustophersmob]

When you say 20-30 lbs of force, do you mean like 20-30 ft-lbs?  I have a feeling it is less than that, as20-30 ft-lbs is quite a lot.  I would be impressed if the backside Philips could handle that much torque.

I would imagine any tool, even a cellidor SAK, with an inline Philips would be able to take far more torque than the backside ones based on Mr. Whippy's findings.

[Lynn LeFey]

As I have no real way of measuring foot pounds... imagine you tied about 20 or 30 pounds to a stick with a rope and twisted your wrist to wrap the rope around the stick, raising the weight. That's what I'm talking about. This is really hard to actually gauge even, as I would have to somehow also take away the dowward effort I was applying to the driver to keep it from camming out of the screw. So... I can only make the wildest of estimations.

As for in-line drivers... I DID try the can opener small flathead on the same screw. There was a LOT of effort required on downward force to overcome camming, but it didn't seem to be torquing the tool apart, so I suspect you're right in that the inline phillips (in an Explorer, for instance) wouldn't have had the problem that the backside Phillips had.

[gustophersmob]

Yeah, I think the thicker pins, the wider tang and the pins going all the way through the scales (alox, pliers MT) or the ferrules (cellidor) allow the force of the torque to be distributed over more area.

Seems like the only thing holding the backspring driver in place is the thin aluminum liner which doesn't take much force to deform.

[clickstop]

It may be just me, but I HATE the back layer tools on SAK's. The phillips, as mentioned, can't take too much torque, and all of the tools suffer from snapping closed when a lot of pressure is applied. I actually think that the hook is the best tool for that placement, unless Victorinox can figure out a way to keep the other tools locked open like Wenger.

[Syph007]

Standard SAKs are held together with soft brass pins in soft aluminum.  Nothing there to handle huge forces on such a tiny pivot.  It is too bad though I agree.

[Northern Geek]

Good argument for the corkscrew if nothing else..

[Zed]

for me if a screw needs more toque i would rather use a proper driver, my tinkers phillips as any MT for me is a back up when ive not got the proper tools, i used my tinkers alot at work over the summer and it performed well but of course a little fiddly to use compared to a inline driver, 

[AimlessWanderer]

I've found that I much prefer a corkscrew on a SAK anyway, and I do like the mini driver that stows in there. When I have used a Phillips on a SAK I much prefer an inline one as it stays open better (I find the inadvertant closure more annoying than torque limits). I've never found an inline Phillips inadequate although I have never subjected them to too much force, but I've never really got on with the backspring Phillips at all.

Before I realised it's only corkscrew SAKs that make the carry rotation, I did get a couple with the backspring driver - Deluxe Tinker was my second ever SAK, but hardly ever gets carried (I ought to get rid of it really) - Tinker Small and Salesman both with "can key" drivers sit in a box with my "snoozers" and may one day be used for parts 

[MARIOS7319]

When i was working for the official distributor of Victorinox in Greece, I've seen a lot of damaged SAKs but nothing like this.
I agree that probably the back-side philips is not made to handle that much torque.
It's something that Victorinox's design team has to address it, at least for the 111mm SAKs.

[Syph007]

Steel liners and pivots are what is needed, like wenger uses on their big ranger models.

[ironraven]

Steel liners and pivots are what is needed

Here here!

That's what modders with cooler tools than I'll ever have get to think about.

[Singh]

Steel liners and pivots are what is needed, like wenger uses on their big ranger models.

does Vic use steel liners and pivots on their 111mm models?

[Northern Geek]

Steel liners and pivots are what is needed, like wenger uses on their big ranger models.

does Vic use steel liners and pivots on their 111mm models?

Just on the locking liner from what I can tell on my OH Forester. The outer liners seems to be aluminum still.

[Syph007]

Steel liners and pivots are what is needed, like wenger uses on their big ranger models.

does Vic use steel liners and pivots on their 111mm models?

Nope.  The locking liner part is metal though, but you can see the brass on the inside.  The big wengers are all steel rivets and outer liners.  I think the inside ones are still Al though Id have to look.

[Styerman]

The only thing I trust the backspring phillips of a SAK for , is use as a fistload . Give me the corkscrew every time .

During my military time ( back in the Jurassic period ) , the rendition of the huntsman with the backspring philips + a bit of paracord + plus a cordlock was often used in off duty situations , in nonpermissive enviroments .

Chris