AIRCRAFT QUALITY BOLTS



I sprayed LPS-3, which dries to a waxy film, into the boxes of lag screws, and I predrill oak and pressure-treated SYP for the shank and threads, somewhat undersized since the fasteners need to withstand an estimated half ton of snow and ice on the roof. . AFAICT the hard wood scours off some of the zinc, so wax doesn't really have a chance.
I stopped waxing furniture screws because it interferes with staining. I spent this morning sanding off a misguided amateur puttying and staining job in the club's bathroom. On the way home I raided HD's rack of unpretty PT 4x4's at 70% off. The firewood it will support doesn't care what it looks like.
jsw
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On Mon, 10 Feb 2014 13:05:22 -0500, "Jim Wilkins"

Are you using tapered drillbits? If you're scouring the galv off it on the way in, the hardware won't last in PT, anyway. LPS-3 should be good.

Ewwwwwwwwwwwww! Wood shouldn't be stained. Use a clearcoat, fer Crom's sake! </purist> But if you must stain, finish the wood first, then drill and assemble. Pieces of carpet on your drillpress are friendly to prefinished furniture components.

Funny, that. ;)
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wrote:

But "billet" is not a "cast" block. Billet is technically a "forged" block - with the close grain structure associated with forged metal.
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On Sunday, February 9, 2014 7:10:45 PM UTC-5, John B. wrote:

You need to refresh your memory on aluminum alloys. As I remember all the marine alloys are five thousand and something.
Dan
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On Sun, 9 Feb 2014 17:32:13 -0800 (PST), " snipped-for-privacy@krl.org"

But they will be used in the T6 condition - which is about the hardest AND toughest an aluminum alloy can be - Solution Heat trested and artificially aged..
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On Sun, 09 Feb 2014 21:34:50 -0500, snipped-for-privacy@snyder.on.ca wrote:

But not applicable to the 5xxx alloys, which are strengthened by cold working, not heat treating.
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On 2/9/2014 9:27 PM, Ned Simmons wrote:

5xxx alloys are used for structural items? I never heard of that before.
Tanks, fairings, stuff like that that is usually deep formed.
But not for spars, masts, stressed skins, etc.
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wrote:

You're reading something I didn't say, I only said that 5xxx alloys are not heat-treatable. See my other post re spar extrusions and 6xxx aluminums..
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wrote:

Which means they can NOT be T6. 1XXX, 3XXX and 5XXX are not heat treatable. 5XXX is a Magnesium alloy and is weldable. 1XXX are "pure" aluminum, 3XXX are Manganese alloys. The 6XXX are heat treatable, weladable magnesium silicone alloys - the silicone allows the heat treating.(forms magnesium silicide wich is "disolved" into the metal by solution heat treating.
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On Mon, 10 Feb 2014 08:18:02 -0500, snipped-for-privacy@snyder.on.ca wrote:

Ain't that what I said?
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On Sun, 09 Feb 2014 21:34:50 -0500, snipped-for-privacy@snyder.on.ca wrote:

A substantial amount of the high performance sailboat masts and spars are 6061, usually marked "T6" :-) I've no idea why as 5052 and 6061 are roughly the same strength so I assume it has something to do with availability or cost.
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wrote:

My guess is strength after welding and extrudability. 6061 will naturally reharden after welding, though not to its pre-welded T6 condition. 5052 will remain more or less annealed near any welds.
Extrudability: http://www.substech.com/dokuwiki/doku.php?id=aluminum_extrusion#extrudability_of_aluminum_alloys
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wrote:

Perhaps. There is usually a certain amount of welding on masts and spars, if only to attach the end fittings, and I suspect that it is unlikely that every shop has a forty or fifty foot heat treating oven ;-)
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On 2/10/2014 7:40 PM, John B. wrote:

None of my spars have ever been welded. The spreader fittings, mast head crane. etc were always bolted.
Although there are some specialty masts that are tapered and thus welded.
No, I suspect the reason for 6061-T6 is because the spars are almost always extruded.
And the stable temper of T6...
And the difference in tensile strength! 5052 yields at 28k 6061 yields at 40k
GENERAL ALUMINUM INFORMATION 1100 This grade is commercially pure aluminum. It is soft and ductile and has excellent workability. It is ideal for applications involving intricate forming because it work hardens more slowly than other alloys. It is the most weldable of aluminum alloys, by any method. It is non heat-treatable. It has excellent resistance to corrosion and is widely used in the chemical and food processing industries. It responds well to decorative finishes which make it suitable for giftware.
2011 This is the most free-machining of the common aluminum alloys. It also has excellent mechanical properties. Thus, it is widely used for automatic screw machine products in parts requiring extensive machining.
2014 & 2017 The 2017 alloy combines excellent machinability and high strength with the result that it is one of the most widely used alloys for automatic screw machine work. It is a tough, ductile alloy suitable for heavy-duty structural parts. Its strength is slightly less than that of 2014.
2024 This is one of the best known of the high strength aluminum alloys. With its high strength and excellent fatigue resistance, it is used to advantage on structures and parts where good strength-to-weight ratio is desired. It is readily machined to a high finish. It is readily formed in the annealed condition and may be subsequently heat treated. Arc or gas welding is generally not recommended, although this alloy may be spot, seam or flash welded. Since corrosion resistance is relatively low, 2024 is commonly used with an anodized finish or in clad form (?Alclad?) with a thin surface layer of high purity aluminum. Applications: aircraft structural components, aircraft fittings, hardware, truck wheels and parts for the transportation industry.
3003 This is the most widely used of all aluminum alloys. It is essentially commercially pure aluminum with the addition of manganese which increases the strength some 20% over the 1100 grade. Thus, it has all the excellent characteristics of 1100 with higher strength. It has excellent corrosion resistance. It has excellent workability and it may be deep drawn or spun, welded or brazed. It is non heat treatable. Applications: cooking utensils, decorative trim, awnings, siding, storage tanks, chemical equipment.
5005 This alloy is generally considered to be an improved version of 3003. It has the same general mechanical properties as 3003 but appears to stand up better in actual service. It is readily workable. It can be deep drawn or spun, welded or brazed. It has excellent corrosion resistance. It is non heat-treatable. It is well suited for anodizing and has less tendency to streak or discolor. Applications same as 3003.
5052 This is the highest strength alloy of the more common non heat-treatable grades. Fatigue strength is higher than most aluminum alloys.In addition this grade has particularly good resistance to marine atmosphere and salt water corrosion. It has excellent workability. It may be drawn or formed into intricate shapes and its slightly greater strength in the annealed condition minimizes tearing that occurs in 1100 and 3003. Applications: Used in a wide variety of applications from aircraft components to home appliances, marine and transportation industry parts, heavy duty cooking utensils and equipment for bulk processing of food.
5083 & 5086 For many years there has been a need for aluminum sheet and plate alloys that would offer, for high strength welded applications, several distinct benefits over such alloys as 5052 and 6061. Some of the benefits fabricators have been seeking are greater design efficiency, better welding characteristics, good forming properties, excellent resistance to corrosion and the same economy as in other non heat-treatable alloys. Metallurgical research has developed 5083 and 5086 as superior weldable alloys which fill these needs. Both alloys have virtually the same characteristics with 5083 having slightly higher mechanical properties due to the increased manganese content over 5086. Applications: unfired pressure vessels, missile containers, heavy-duty truck and trailer assemblies, boat hulls and superstructures.
6061 This is the least expensive and most versatile of the heat-treatable aluminum alloys. It has most of the good qualities of aluminum. It offers a range of good mechanical properties and good corrosion resistance. It can be fabricated by most of the commonly used techniques. In the annealed condition it has good workability. In the T4 condition fairly severe forming operations may be accomplished. The full T6 properties may be obtained by artificial aging. It is welded by all methods and can be furnace brazed. It is available in the clad form (?Alclad?) with a thin surface layer of high purity aluminum to improve both appearance and corrosion resistance. Applications: This grade is used for a wide variety of products and applications from truck bodies and frames to screw machine parts and structural components. 6061 is used where appearance and better corrosion resistance with good strength are required.
6063 This grade is commonly referred to as the architectural alloy. It was developed as an extrusion alloy with relatively high tensile properties, excellent finishing characteristics and a high degree of resistance to corrosion. This alloy is most often found in various interior and exterior architectural applications, such as windows, doors, store fronts and assorted trim items. It is the alloy best suited for anodizing applications - either plain or in a variety of colors.
7075 This is one of the highest strength aluminum alloys available. Its strength-to weight ratio is excellent and it is ideally used for highly stressed parts. It may be formed in the annealed condition and subsequently heat treated. Spot or flash welding can be used, although arc and gas welding are not recommended. It is available in the clad (?Alclad?) form to improve the corrosion resistance with the over-all high strength being only moderately affected. Applications: Used where highest strength is needed.
And
ALUMINUM TEMPER DESIGNATIONS Temper designations of wrought aluminum alloys consist of suffixes to the numeric alloy designations. For example, in 3003-H14, 3003 denotes the alloy and ?H14? denotes the temper, or degree of hardness. The temper designation also reveals the method by which the hardness was obtained. Temper designations differ between non heat-treatable alloys and heat-treatable alloys. and their meanings are given below:
Non Heat-Treatable Alloys
The letter ?H? is always followed by 2 or 3 digits. The first digit indicates the particular method used to obtain the temper. as follows:
? Hl means strain hardened only.
? H2 means strain hardened, then partially annealed.
? H3 means strain hardened, then stabilized.
The temper is indicated by the second digit as follows:
2 1/4 hard
4 I/2 hard
6 3/4 hard
8 full hard
9 extra hard
Added digits indicate modification of standard practice.
Heat-Treatable Alloys
-F As fabricated
-O Annealed
-T Heat treated
The letter ?T? is always followed by one or more digits. These digits indicate the method used to produce the stable tempers, as follows:
-T3 Solution heat treated, then cold worked.
-T351 Solution heat treated, stress-relieved stretched, then cold worked.
-T36 Solution heat treated, then cold worked (controlled).
-T4 Solution heat treated, then naturally aged.
-T451 Solution heat treated, then stress relieved stretched.
-T5 Artificially aged only.
-T6 Solution heat treated, then artificially aged.
-T61 Solution heat treated (boiling water quench), then artificially aged.
-T651 Solution heat treated, stress-relieved stretched, then artificially aged (precipitation heat treatment).
-T652 Solution heat treated, stress relieved by compression. then artificially aged.
-T7 Solution heat treated, then stabilized.
-T8 Solution heat treated, cold worked, then artificially aged.
-T81 Solution heat treated, cold worked (controlled), then artificially aged.
-T851 Solution heat treated, cold worked, stress-relieved stretched, then artificially aged.
-T9 Solution heat treated, artificially aged, then cold worked.
-T10 Artificially aged, then cold worked.
Added digits indicate modification of standard practice.
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wrote:

Not really "specialty". Quite a few masts on, say 40+ foot boats are tapered by cutting and welding. My last boat, for example. 42 ft. deck stepped with about 25% of the top tapered. Partially I think to make more room for the jib furler. The spreader brackets were also welded to the mast, as was a bracket for the steaming light.










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wrote:

I did quite a bit of welding on masts back in the bad old days, mostly on boats 40 feet and up as well. Halyard winch bases and radar mounts were the first things that came to mind.
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replying to Ned Simmons , Bob Lowe wrote:

Okay Ned, I have a question...I don't know how far back your bad old days were but in the 50's when I needed some aluminum welding done I always had it done by Heliarc, as if the gas welding flux hadn't been developed yet...I really don't know this for sure. But now that I am retired my 'To Do' list has grown to a couple of life times long and I can't get everything crammed in. I have I think at least 3 gas welding outfits, the regular industrial, a mid sized venturi air type and a little Map Gas-Oxygen affair. I haven't gotten around to teaching myself how to weld aluminum. I see the flux coated gas rod and this is my question....could this be an easy way to get started on this? Or could you recommend another starting point? I don't want to bother with getting into the Mig welding area.
Thanks,
Bob Lowe
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On Wed, 12 Feb 2014 02:18:02 +0000, Bob Lowe

I learned to gas weld aluminum in 1951 and it was a bitch. My suggestion is to arc weld anything thick enough and buy a TIG for the thin stuff.
The problem with gas welding, and to some extent TIG welding aluminum is that the metal doesn't change color when heated. You are heating the parent metal, waiting for a puddle to form and suddenly the whole thing falls on the ground.
The technique is to keep poking the spot where you intend the puddle to form with the filler rod. If all goes well you will poke and a bit of rod will melt off and there's your puddle.
But it is so much easier to just use the TIG or even a plain old arc welder (with aluminum rods :-).
As an aside, not all aluminum can be welded.
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On 12/02/14 12:44, John B. wrote:

I got shown how to weld aluminium with gas back in about 1985 by a welding instructor, he wasn't a real welder but taught the course and could passably gas weld aluminium. I had already taught myself to OA weld so was good at steel and I noticed that there is a subtle change in the surface appearance of the aluminium before it drops on the floor and that is when to add the filler to keep the pool under control. After about 10 minutes I was welding Al better than the instructor. Never had any issues with glare either, the flux just seemed to go water clear and wet the surface when near welding temp and I was fine with the standard gas welding filters, maybe the flux in the UK is different. Not gas welded Al for maybe 20 years now as have had TIG to use for Al but don't weld Al that often anyway.

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On Wed, 12 Feb 2014 19:30:28 +0000, David Billington

Yes, a subtle change :-) The new welder doesn't usually see it ... until too late :-)

I've always sort of wondered about that. We learned using a paint on flux and the usual green lens welding goggles and never a mention of glare from the flux.
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