What do you expect?

[Mr. Whippy]

I'm a little surprised at some of the responses in the 111mm Victorinox thread I started here

I called the backside driver design poor.  The obvious (and reasonable ) question was firstly, did I mess up the tool when I modded it.  Afterall, it was no longer of Victorinox design, perhaps I mis-peened the thing.

So, I took a similar (but not identical) Victorinox original backspring Phillips and applied torque via a torque wrench to see what it would handle.

At my torque wrench's lowest setting (10 Nm), it ripped out BEFORE actually reaching 10 Nm torque. 

The next responses were, what do you expect? It's only a MT, it's just a brass pin.  To me, that is pathetic! LESS than 10 Nm for that style of driver is no better than toy status (or decoration). 

In my mind, if a tool design can't stand up to meager forces, it shouldn't be incorporated into the MT/SAK.  In this case, either only offer a corkscrew or just leave the thing off completely. 

Other thoughts?

[Sea Monster]

I think the Vic backspring phillips has a bunch of other problems anyway so I don't advocate it a great deal (Though I do love the option, since a driver is damn handy when you need it)


I've lost my chain of thought.

Oh well, to fill the time, do you think you could get your torque wrench out again and find the strength of the main knife blade (at the pin/liner/tang point)
I'm assuming that'd have the highest strength, so it gives as a ballpark of what is fair on the tool in general.

(And if you're feeling wealthy, test an Alox too )

[Andreas]

I understand your frustration. Victorinox also has an inline phillips head screwdriver that would probably take more stress. Having opened up SAKs I know how fragile the backside tools look, so I'm also not surprised it would give out quickly, and I agree with you it shouldn't.

[Benner]

Lets face it, those drivers suck.  I'd sooner have a corkscrew any day.

But, I don't see it as a high torque driver.  I just see it as a driver that is stuck in a space to add extra function - not necessarily a T-driver, more of a battery compartment type screw remover.

BTW, I think you deserve a medal for actually finding a screw these things can bite into so that any torque can be applied    

[Andreas]

I just see it as a driver that is stuck in a space to add extra function - not necessarily a T-driver, more of a battery compartment type screw remover.

That was my thought exactly with the PS4 bit driver, where people were worried about the torque. Being T-shaped it does give off the vibe that it's "bad ass" though so you would think it could handle something stronger.

BTW, I think you deserve a medal for actually finding a screw these things can bite into so that any torque can be applied    

Indeed, that screwdriver is generally too big for anything I myself do. I like the one on the Midnite Manager (amongst others), the magnetic combination bottle opener and phillisp head screwdriver. It's mch smaller and is more of a !battery compartment" type screwdriver

[evil510]

A bit disheartening seeing as one of my current projects is a one hand trekker. I have already enlarged the two inner holes to match those of the two outer larger holes so I only need to worry about one size and hopefully add a little bit more strength in the process. Holes also enlarged on the awl and phillip driver as well. More than likely, I will be going with a stainless steel bolt system. I tend to push my tools hard, so I will keep my fingers crossed.....

~ evil ~

[Neil]

I try to avoid phillips on the back except for whittlers.  Then only so it fits in the hand better.  The only time I advocate a phillips on the back of a SAK is if it doesn't have an opener layer, as in practical use I find the tip of the cap opener easier to use than a backspring phillips.  I have no real use for a corkscrew but I'd rather have that so I can carry the mini screwdriver than a phillips on the back.

Inline phillips are a different matter and I find those very useful.

[evil510]

Inline phillips are a different matter and I find those very useful.

Hey Neil. Are those equivalent to the thickness of two layers?

[Benner]

I'm not Neil, but the driver layer is 2 thick yes.

[evil510]

I'm not Neil, but the driver layer is 2 thick yes.

Thanks Benner!   I told myself I would limit my time/effort investment on this particular mod by just making a new blade, new scales and adding scissors. Now you all have evil thinking.....

[parnass]

A Phillips screw is designed to be torque limited, i.e., the driver tool is supposed to "cam out" before breaking something.  I would consider a Phillips driver which breaks while turning a screw to be defective in either material or design.

[grimm_kaosboy]

Luckily I have always thought of the backspring phillips driver to be "just" a driver, not a t-handled torque driver. Which is good, because watching a grown man cry like the fat kid who dropped his ice cream cone in dog poop is never pretty.
Mr. Whippy, thanks a million for doing the torque tests as I now will be sure to use an in-line phillips driver if the screw seems very tight. <10 Nm vs. @30 seems the wise way to go...

[jzmtl]

I think you need to re-look at your measuring standard. You are using tools and units that's meant for 3/8"+ hardened steel bolts, not a toothpick sized brass pin. Let's say it failed at 8 N.M, and convert it into more realistic units for something this size. What's the radius of the phillips, 3 mm? So it means at the edge of the pin/driver it's sustaining 271 KG of force, that's a lot for a non-hardened brass pin.

[DaveK]

A Phillips screw is designed to be torque limited, i.e., the driver tool is supposed to "cam out" before breaking something.  I would consider a Phillips driver which breaks while turning a screw to be defective in either material or design.

That sir, is a bloody good point! I hadn't thought about it in those terms. 

[Mr. Whippy]

I think you need to re-look at your measuring standard. You are using tools and units that's meant for 3/8"+ hardened steel bolts, not a toothpick sized brass pin. Let's say it failed at 8 N.M, and convert it into more realistic units for something this size. What's the radius of the phillips, 3 mm? So it means at the edge of the pin/driver it's sustaining 271 KG of force, that's a lot for a non-hardened brass pin.

Both inline and backside drivers rotate around a brass pin.  The difference between them (as DaveK pointed out) is how much surface area is in contact between the tool and the adjacent liners.  The brass pin fails because it was never meant to be the stressed pivot point.  On the backside driver, the force/unit area is HUGE compared to the platelike surface of an inline driver.

To me, that is the crux of this issue.

[jzmtl]

I agree with you on that, but remember the phillips was never meant to be there (and need to be treated as such), it was originally a substitute for the corkscrew for the american market because they deemed americans don't drink wine/want corkscrews.