J

jmartinez443

Well Known Member
So I'm removing the rear of the baggage compartment on my QB8A and I stripped 3 out of the eight screws that the crew in the Philipines had put in to hold the baggage compartment.

But I digress, I'm thinking that I want to start using torx screws to fasten my baggage compartment and floors and I have two questions:

1) Does anyone have a good source for torx screws (I found them at McMaster but I'm not sure if I'll be able to order)?

2) What's the best finish to get to use on alum (steel, stainless steel, zinc plated, black oxide, or none of the above)). I'm obviously concerned with minimizing corrosion due to dissimilar metals.

Thanks in advance,
 
Good idea

But I went a slightly different route.

I put C/S SS torx screws in all the access panels , wing root fairing covers etc. I can't remember where I got them from but Walter Tondu has them listed on his page...Highly recommended.

For the rear bulkhead I went to my local hardware store and bought a box of phillips head screws but the ones that can be used with a phillips bit OR a flat bit.

I then use a flat bit to put them in or remove them...never strip. cad plated (or shiny silver) work great for this application.

Oh and when putting on all your access plates or rear bulkhead for Heavens sake use a battery drill (set torque down low) it speeds up the deal no end.

Frank
 
The cad-coated hardware supplied is probably best for prevention of galvanic corrosion. In practice, stainless steel seems to work fine as well however.

I share your displeasure with the cad hardware with respect to its lack of toughness and have substituted stainless steel in many places. Also note that the standard 1/2-inch long screws Vans supplies for the approximately two zillion nutplates on our planes are unnecesarily long - 3/8 is plenty to penetrate through the nutplates and saves 0.05 grams x 2 zillion in weight:)

erich
 
I know some of the hardware is soft, but a good phillips bit is the best way to handle them. Some cheaper bits are either poorly made or don't properly fit the screw head. And not using just the proper size can exacerbate things. I use a quality Snap On bit (#3) for all the # 6 and 8 screws and a quarter inch rachet with appropriate extensions. Most common screwdrivers are worthless.

Roberta
 
Are you using a power driver? Do you have the clutch set properly? It should never turn or spin the bit inside the screw head. If you do then it is not set correctly.

If you cannot get the screw to run all the way in you might want to put a corresponding tap into the dril and "cleanout" the threads. Seems I have to do this about once a year.
 
I"m afraid I have to agree with Jorge on this one. You won't find a phillips head screw on my airplane. I use either torx or allen head. I get torx from microfasteners.com.
 
Geico266 said:
Are you using a power driver? Do you have the clutch set properly? It should never turn or spin the bit inside the screw head. If you do then it is not set correctly.
Click to expand...

Good old elbow grease. The screws just happened to be stuck in there and when I cranked on them to get 'em out they stripped.

Stainless Steel Torx it is for me then. BTW McMaster has the #8-32 for about $8 for 50. I even like the lower profile button heads. I'll get an assortment of flat, pan head and button head anyway.

Thanks all for your responses.
 
jmartinez443 said:
Good old elbow grease. The screws just happened to be stuck in there and when I cranked on them to get 'em out they stripped.
Click to expand...

Remind me not to arm wrestle you! :D

I don't take out 3 screws without getting a power driver out. The clutch is set low. I do replace the screws if they get worn.
 
If you have a Phillips head screw that the driver skips in, even a little then do yourself a huge favor, and throw it away as soon as you get the screw out.

The main reasons for a driver to skip in the screw head are; 1. screw too tight---for whatever reason. 2. bad tip on driver-----check often, and get rid of bad ones. 3. wrong size driver. 4. driver not pushed into the screw hard enough. Also, not that we use them on our RV's, the small "phillips" head screws found on a lot of Japanese stuff isnt really Phillips------go to a good hobby store for the correct "Japanese Industrial Standard" drivers.

The best ways I have found to remove stripped Phillips screws------for lightly stripped/just starting to skip, I use a product called "screw grab"---works well.

If that doesnt do the job, or for badly stripped head, I have a set of screw extractors form Sears that have never failed to either remove the screw, or at least the screw head.

Screw grab http://main.screwgrab.com/

Sears "Screw out" http://www.sears.com/shc/s/p_10153_12605_00952154000P?vName=Tools&keyword=screw+out

JIS drivers http://centralhobbies.com/Tools/jis.html

Good luck.
 
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I have almost a thousand hours on the RV now, and have maybe replaced 3 or 4 phillips head screws total so far. That covers a lot of annuals and maintenance. I know I wrecked a few being mis-aligned, but with a good driver, they can look pretty bad and still lock on. As others have said, it is all in the driver. Throw away all screwdrivers that don't have replaceable bits. I have never found a one piece screwdriver that is made correctly. With a proper bit, a genuine AN screw is tough to strip. Get some bits from an ACE or other non-discount hardware store and you will probably be ok.

For #8's that are going into nutplates, it is absolutely necessary to use a wax of some sort. Perhaps they don't use that in the Philippines. I use a $1 toilet wax ring for my 1000 year supply. Even on a brand new nutplate, it should be difficult to strip a screw unless the driver is junk. The torque just shouldn't be that high. Without wax it is hopeless.
 
Get some #2 Phillips brand ACR bits, Snap On or SK screwdrivers. All of these have a serrated tip that grips the phillips head screws much better than anything else. I guarantee you'll be surprised at how much better they work. Lowe's carries the ACR bits where the deck screws are or you can buy them from your local Snap-On guy.
 
For the real tight stubborn screws and using the proper Phillips driver set your power drill to a low torque setting and hold it on the screw without letting it strip the head let it hammer away. This will break the screw free. The constant pounding on it works wonders. If you do strip a head because of the wrong driver take a dremel tool with a cut off wheel in it and cut a slot across the head, then use a common blade screw driver to remove the screw. As others above have said use the proper driver bit and throw away any screw that is even marginally distorted. If you don't the next time it will get you.
 
Philip screws

I use a dab of valve grinding paste on the tip of the philips screw driver bit. The valve grinding compound has enough fine grit which helps the bit grip the screw and does not allow the bit to "cam" out of the slot. It comes in tubes, is cheap and is sold through most good auto parts stores. It works very well with troublesome screws and can usually remove them without tearing them up.

Dick DeCramer
RV6 N500DD
Finishing up on RV8 wings
Northfield, MN
 
Fastener-Express.com

I bought mine from Fastener-Express.com.

productimages%5Csocketscrew%5C8-32%20x%2012%20Button%20Head%20Cap%20screw.jpg


8-32 x ?" were $4.31 for a bag of 50. My rule is any (NON-structural 8-32 screws that come out of my plane once get replaced with these. They use a 3/32" hex driver, and I have yet to strip one out. I did torque one down too tight once, though.
 
Aren't all our dimplers/countersinks set up for 100 degree screws. I hate the phillips also. Would love to find a source for 100 degree/ss torx or allen.
Anyone know of a source?
 
Anybody can order from McMaster-Carr. I've got several things from them in my RV-6.

Be careful with stainless screws going into stainless nutplates. You'll gall the threads unless you use some kind of lubricant, even if it's just WD-40. Do it dry and the second time you go to remove the screw, it'll be "welded" in. Don't ask me how I know...

Heinrich Gerhardt
 
Torx Screws

www.microfasteners.com 100 degree countersunk and button head SS torx. T-15 bit on low clutch setting battery drill. Excellent. Also have a small Black & Decker rechageable palm drill to carry on board with small bit set in blow mold case. I also use the Black & Decker with Avery threaded adapter to debur all of my holes. Man, it really takes the 'elbow' out of deburring skins. Very slow rpm, and weighs ounces, and it's reversable.
Mike H 9A/8A
 
robertahegy said:
I know some of the hardware is soft, but a good phillips bit is the best way to handle them. Some cheaper bits are either poorly made or don't properly fit the screw head. And not using just the proper size can exacerbate things. I use a quality Snap On bit (#3) for all the # 6 and 8 screws and a quarter inch rachet with appropriate extensions. Most common screwdrivers are worthless.

Roberta
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Roberta has hit the nail on the head right here!!! I have a Craftsman set of screwdrivers for everyday use (punch, prybar ect....:rolleyes:) But when it's time to get serious, I break out my Snap-on ratcheting screwdriver. Their bits make EVERY OTHER scredriver pale in comparision.

JMOH
Josh
 
jmartinez443 said:
1) Does anyone have a good source for torx screws (I found them at McMaster but I'm not sure if I'll be able to order)?
Click to expand...

McMaster's e-commerce website demanded that I fill in a business name on the checkout page, so I just made something up to put in there and three days later my parts were at my house :)
 
McMC torx are TorxPlus . . .

Be aware that McMC 'torx' screws are now 'torx Plus' screws. They require a different driver (available from McMC of course). They no longer sell 'regular' torx screw. I called McMC about this when I received my first order of their screws and they said it was a patent issue. I actually like the TorxPlus heads better (even more strip resistant). All of my interior (panhead) screws are SS torxPlus now.

The 100 degree flat head screws from MicroFasteners are 'regular' torx heads - even though they call them '6 lobe' (probably another way around the patent problem). All of my flathead screws (both #6 and #8) are these kind.
 
Dennis,

You're right, and McM-C have the different bits to use in ratcheting/electric drivers as well. However, I found that the McM-C #8's use a different size torx bit (#20) to that of a MicroFasteners #8 (#15 bit). If you use a #15 in a McM-C # 8 torx screw, it will strip. Ask me how I know :( However, even if stripped, the right size torx bit will get it out..

and the McM-C torx-plus bits will work in the MicroFasteners torx's..... but are much better.

Allan
 
Oh yeah, the driver sizes . . .

AllanC said:
Dennis,

You're right, and McM-C have the different bits to use in ratcheting/electric drivers as well. However, I found that the McM-C #8's use a different size torx bit (#20) to that of a MicroFasteners #8 (#15 bit). If you use a #15 in a McM-C # 8 torx screw, it will strip. Ask me how I know :( However, even if stripped, the right size torx bit will get it out..

and the McM-C torx-plus bits will work in the MicroFasteners torx's..... but are much better.

Allan
Click to expand...
Good catch on the size number differences on the drivers (torx vs torxPlus). I'd forgotten about that - even though I had to re-order the bits when I got the wrong size initially :eek: I've also used the 'wrong' drivers a few times. It is a pain needing so many different ones.
 
Pozidrive is not philips

These are possibly pozidrive and not philips screws. For power screwdriver installation in manufacturing they typically use pozidrive or prodrive screws (driver doesn't cam itself out of the screw under the higher speeds used like it will with philips heads) and these will strip when you use a philips driver (and damage the driver). The Pozi design has the corners notched out between the cross. The bits are labeled "pz" for pozidrive and "ph" for philips. If your driver (bit) does not seem to fit right in the screw then you probably have a mismatch between the driver and the screw formats.
 
Cad. Steel should be harder, not SS

erich weaver said:
The cad-coated hardware supplied is probably best for prevention of galvanic corrosion. In practice, stainless steel seems to work fine as well however.

I share your displeasure with the cad hardware with respect to its lack of toughness and have substituted stainless steel in many places. Also note that the standard 1/2-inch long screws Vans supplies for the approximately two zillion nutplates on our planes are unnecesarily long - 3/8 is plenty to penetrate through the nutplates and saves 0.05 grams x 2 zillion in weight:)

erich
Click to expand...

This should not be the case if you buy the correct grade of machine screws...

The MS24694 cad steel screws have a tensile strength of 125,000 psi. - which makes them harder than most SS screws... Even the SS version of these MS24694 screws (with a "C" in the part number is only 85,00 psi)

http://www.aircraftspruce.com/catalog/hapages/ms24694.php

However, the similar looking MS35190 screws (and I would bet the ACE Aviation Supply Hardware store ones...:)...) are only 55,000 psi tensile strength.... definitely way softer.... These will prove easy to ^&*% up the Philips slots...:mad:

http://www.aircraftspruce.com/catalog/hapages/ms35190.php

These MS 24693 ones also look the same, but are similar weaker screws - with a SS equivalent...

http://www.aircraftspruce.com/catalog/hapages/ms24693.php

This is one case were it really pays to look at the specifications, and get the best (strongest) cad. plated ones to get a better Philips head slot.

In general, SS screws are weaker and softer...

Know what you are using....:)..... gil A
 
Just Upgrade but stay Aircraft.

To upgrade to the better Cad Plated fastener without spending very much more.

Go from:

AN507 / MS24693S, upgrade to NAS514

AN515 / AN520 / MS35206 / MS35207, upgrade to NAS600/601/602/603...

See this page http://www.gen-aircraft-hardware.com/template.asp?pagename=nas514_600
And the link in this page for the specs.

These are at least twice as strong and identical in function and appearance to what is originally called out, they are just made from a better material, and then heat treated.

If you do not have an aircraft bit for your screwdriver that is actually aircraft, get some now.

For tech page go to
www.gen-aircraft-hardware.com/images/pdf/zephyr-bits.pdf

NOTICE start with the screw size on the far left of the chart.

On an RV most of what you will be using will be D1221AA for the small screws #4, and the D1222AA for the 6-32, 8-32 and 10-32.

On our webstire they are on the left under
(TOOLS)
(Installation Bits)

And one big tip is do not over tighten your screws..

Be aware, Stainless directly against aluminum and throw in some moisture and your aluminum will suffer. Go with Cad Plated when you can.

Have Fun.
 
Interesting reading, but I had the same experience as the original poster. On my -7 QB fuselage, getting the Philippines-installed phillips screws out, even with shiny new Snap-On tools, by hand, was next to impossible. I destroyed half of the screws no matter what technique I used. I also noted that on the plans (don't have them in front of me and I don't remember which sheet) Van's advised using a tap to chase the threads on nutplates close to the skin, to make installation easier.

I've been using new Van's supplied phillips screws with Boelube (because I have a lifetime supply) as I've reinstalled stuff. Have yet to have a problem when removing (which seems to happen over and over). I'll likely continue to use phillips screws because I have a bazillion (even more than a zillion) of them, but they aren't my favorites.
 
Spent many years as a helicopter mechanic. Thousands of screw in those things and all phillips heads. As Roberta said - get superb quality bits. Toss any screws that get even the least bit worn. Rachets are great tools for turning apex bits on stubborn screws as are speed handles. A good trick is to simulate a hammer drill by tapping the end of the screw driver as you apply torque. Just make sure your backing is up to the force. In the thousands of phillips screws I've removed, I only used an easy out 2 or 3 times.

If you choose to use anything other than phillips, ensure you pack your drivers in the plane with you. You may find it difficult to get tools on the road at inconvenient hours.

Jekyll
 
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Amen to that

Was darned lucky to be able to borrow some tools to remove the cowl that used Torx bits in a couple of places.

This was only 35 miles from home...About an hour each way by car across the mountain range!

If I intend to depart the pattern the tool kit ets thrown in!

Frank
 
Tapping nutplates

I suffered the problem of seized screws!
A LAME reckoned that the only idea was to put a tap through the nutplate first if it were in a position where the screw was to be removed in the future.

My cowls are screwed on rather than using piano hinges and I haven't had any problem with the screws loosening with vibration after having tapped each nutplate, but I can get them out without any trouble with my electric screwdriver. If one is stuck then the impulse setting on the driver shakes them out OK!

Ted
(RV-6A "rough Red")
 
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