Date: Tue, 23 Jan 1996 08:13:59 -0600 From: Scott Mandel Subject: Chap 8 & Chap 9 Nuts and Bolts I found out last night my AN525-416R16 are too short to go through the seat belt mounts. I remembered some postings about this happening to other people so I decided to check the archives this morning to find out if there are any other mis-sized hardware in Chapter 8 or Chapter 9. I found a post to change the 16 X MS24694-S60 to 16 X MS24694-S64. 1. Has anyone else found any other hardware changes to Chapter 8 or Chapter 9? I'm planning to order Chapter 9 today and I'll also order the changes from Chapter 8. _________________ ______________________ / Scott L. Mandel \ /Email: mandel@esy.com \ \_________________/_________________________\______________________/ | \\|// Hydrographic Source Assessment System (HYSAS) \ | (o o) \_______ \_o00o~(_)~o00o______________ Email: scott_mandel@qmailgw.esy.com \ / E-System Garland Division \ | | 1200 S. Jupiter Road ||---(X)---| Voice: 1-214-205-8762 | | Garland, Tx. 75042 | o/o\o Chap 8 Fax: 1-214-205-6012 | \___________________________/______________________________________/ Make it idiot proof and someone will make a better idiot. Date: Fri, 9 Feb 1996 07:57:40 -0600 From: Scott Mandel Subject: Chapter 8 Machine Screws Hi Guys, I had to re-order the machine screws for the seat belt mountings the AN525-416R16 s were too short. I ordered AN525-416R20 s. I received them last night and they are the right length, but seem to be made of a different material. They aren't the brass color of the R16s they are more like rough aluminum or galvanized steel. I don't know a darn thing about nuts and bolts or metals but can anyone tell me who has received R20s if they got the same thing? Does any- one know what they sent me? ___________________________________________________________ / \\|// |---(X)---| \ | (o o) o/o\o Chap 9 | \_o00o~(_)~o00o_____________ | / Scott L. Mandel \ Email: mandel@esy.com | | 6813 Pendrige Drive | Voice: 1-214-205-8762 | | Plano, Tx. 75024 | Fax: 1-214-205-6012 | \___________________________/_______________________________/ Make it idiot proof and someone will make a better idiot. Date: Tue, 26 Mar 1996 10:45:15 -0800 From: harvey3@ix.netcom.com (Neil K. Clayton) Subject: Mil Standard Can anyone help me with the format for the mil spec for screws and nuts? I know how "AN" standard is defined, but I have no documentation for MS. In particulaar I need to know about "MS21069-L3" (fuel cock bracket) and "MS24694-S52" screws. Which digits means what? Thx Neil Date: 14 May 1996 10:52:03 -0700 From: "Judd Stewart" Subject: COZY: Fastener Torque Value Hello All; Does anybody know what the correct torque value required on the fasteners in our plane. There is published data on a metal-metal interface but what of a metal-glass/resin-metal interface? Thanks Judd Stewart 619.552.5581 judd_stewart@cpqm.saic.com Date: Wed, 27 Nov 1996 19:01:13 -0500 From: Paul Burkhardt Subject: COZY: Aluminium vs Steel AN fittings I just was fitting the oil cooler and needed to remove the existing AN fittings ( it was a used unit) Upon removal I realized the fitting were made of steel. The cooler is made from aluminium( at least the female part of the fitting was) Is it necessary to use steel in this area, or can I install aluminium fittings here. Steel cost twice as much. Paul Burkhardt PS I also installed the B and C oil filter (90) and its nicely made , you do however have to offset the oil cooler from center though. Date: 28 Nov 96 00:03:17 EST From: INFINITY Aerospace <72124.347@CompuServe.COM> Subject: COZY: Aluminum Fittings Hi Paul, >I just was fitting the oil cooler and needed to remove the existing AN fittings ( it was a used unit) Upon removal I realized the fitting were made of steel. The cooler is made from aluminium( at least the female part of the fitting was) Is it necessary to use steel in this area, or can I install aluminium fittings here. Steel cost twice as much. Paul Burkhardt PS I also installed the B and C oil filter (90) and its nicely made, you do however have to offset the oil cooler from center though.< You'll have to talk to metallurgy guys about mixing steel and aluminum concerning corrosion over time. At least get steel fittings that are plated. Aluminum fittings should be fine. I use aluminum Swagelok fittings throughout, and sometimes aluminum AN fittings when needed (pipe to hose fittings), unless I can't get a particular fitting I want. As a rule of thumb, the aluminum fittings are about 1/3 the weight of the steel fittings, yet still have about 2/3 the strength of the steel fittings. I, also, use aluminum aircraft bolts for non-critical fastening to save weight. Swagelok say's they have the lowest leak rate in the industry, and I find they are about 1/3 to 1/2 the cost of AN fittings - check with your local dealer for a huge free catalog, or call their main office in Solon, OH. Also, check out Earls Performance Parts [(310) 609-1602] for their catalog - same AN fittings, but less cost. They have hoses and other really neat fittings, too. If memory serves, the aluminum fittings have a burst pressure of about 5700 PSI. I also use 5052-0 aluminum tubing throughout. I called Alcoa Aluminum long ago for the specs for all aluminum tubing, and have talked with the fittings mfg.'s concerning the specs of their fittings. Your Click Bond fasteners are on their way. HTH. Infinity's Forever, JD From: Marc J. Zeitlin Subject: COZY: Aluminium vs Steel AN fittings (fwd) Date: Sun, 1 Dec 96 13:42:57 EST Paul Burkhardt wrote: >.............. The cooler is made from aluminium( at least the female >part of the fitting was) Is it necessary to use steel in this area, or >can I install aluminium fittings here. Steel cost twice as much. As a general rule, you do not EVER want to thread aluminum onto aluminum (this sounds vaguely familiar - I'll bet we discussed this a year ago or so :-) ). You will get galling of the aluminum threads, and you will essentially weld the two parts together. Steel (plated or unplated) will almost always be better than aluminum because of this galling problem. Try it out - buy a couple of aluminum AN fittings, or better yet pipe threads, and screw them together tightly. See what percentage of the time you can get them apart :-). -- Marc J. Zeitlin Email: marcz@an.hp.com From: "Kerry Lamb" Subject: Re: COZY: Aluminium vs Steel AN fittings (fwd) Date: Mon, 2 Dec 1996 08:34:21 -0500 Marc is correct on this, some types of stainless will also gall (use to have a stainless pistol that required special goo to avoid this) Kerry ---------- > From: Marc J. Zeitlin > To: cozy_builders@hpwarhw.an.hp.com > Subject: COZY: Aluminium vs Steel AN fittings (fwd) > Date: Sunday, December 01, 1996 1:42 PM > > Paul Burkhardt wrote: > > >.............. The cooler is made from aluminium( at least the female > >part of the fitting was) Is it necessary to use steel in this area, or > >can I install aluminium fittings here. Steel cost twice as much. > > As a general rule, you do not EVER want to thread aluminum onto aluminum > (this sounds vaguely familiar - I'll bet we discussed this a year ago or > so :-) ). You will get galling of the aluminum threads, and you will > essentially weld the two parts together. Steel (plated or unplated) > will almost always be better than aluminum because of this galling > problem. Try it out - buy a couple of aluminum AN fittings, or better > yet pipe threads, and screw them together tightly. See what percentage > of the time you can get them apart :-). > > -- > Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.0-6 #10979) id <01ICJB8OAUEQ000G7T@SERV05.SLAC.STANFORD.EDU> for marcz@hpwarhw.an.hp.com; Mon, 02 Dec 1996 13:27:34 -0800 (PST) Date: Mon, 02 Dec 1996 13:29:07 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Aluminium vs Steel AN fittings (fwd) >Paul Burkhardt wrote: > >>.............. The cooler is made from aluminium( at least the female >>part of the fitting was) Is it necessary to use steel in this area, or >>can I install aluminium fittings here. Steel cost twice as much. > >As a general rule, you do not EVER want to thread aluminum onto aluminum >(this sounds vaguely familiar - I'll bet we discussed this a year ago or >so :-) ). You will get galling of the aluminum threads, and you will >essentially weld the two parts together. Steel (plated or unplated) >will almost always be better than aluminum because of this galling >problem. Try it out - buy a couple of aluminum AN fittings, or better >yet pipe threads, and screw them together tightly. See what percentage >of the time you can get them apart :-). > >-- >Marc J. Zeitlin Email: marcz@an.hp.com I totally agree. Another important consideration was covered in Rutan's Canard Pusher (sorry, I don't know the issue). Tapered pipe threads can exert tremendous forces on the fittings, and whatever they are screwed into. This can easily crack the fitting, and not always right while you are in the act of screwing it in, either! Rutan experienced several cracked fittings in engine compartments, in spite of vigilence and caution. He made it a mandatory ground item in CP to replace all engine compartment Aluminum AN fittings with steel. The burst strength was never an issue. The difference in weight and cost is trivial, and worth it. A seconday caution, here. Be very careful about giving it that little "extra" turn to make a fitting line up. You could easily split your engine case or oil cooler, too! Back off, start over, and try another fitting. Corrosion has never been a problem for me, with steel fittings. If you are worried about it, get the stainless ones. If your aircraft supplier doesn't have stainless, try a local hydraulic supply. They are also known as "JIC" fittings. Just make absolutely sure that you have the 37 1/2 degree fittings, not the 45 degree fittings for automotive use. I know of at least one fatalaty that resulted from this exact mixup (wrong flaring tool). By the way, we use a tremendous number of Swagelok fittings at work (Physics R&D). I have been tempted to use them on aircraft, and I see no obvious reason why not. I don't know how they would hold up to vibration. If I did use them, I would definitely use the stainless ones, not the aluminum. Since I am basically a chicken, I will probably stick with the tried and proven AN fittings, for aircraft use. Regards, Howard Rogers A&P 2005148 by SERV05.SLAC.STANFORD.EDU (PMDF V5.0-6 #10979) id <01ICKDT26IT8000GT1@SERV05.SLAC.STANFORD.EDU>; Tue, 03 Dec 1996 07:52:04 -0800 (PST) Date: Tue, 03 Dec 1996 07:53:40 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Aluminium vs Steel AN fittings (fwd) >Marc is correct on this, some types of stainless will also gall (use to >have a stainless pistol that required special goo to avoid this) > >Kerry > Kerry, I work with stainless a lot, and you are partially correct. Stainless will gall, when in contact with other stainless, such as a stainless nut on a stainless bolt. Our standard solution to this is to plate one or the other with .0002 of silver, as lubricants are usually forbidden in the clean environment of Ultra High Vacuum. Stainless against steel, aluminum, brass, etc. is NOT a galling problem, however. Howard Rogers, A&P 2005148 by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICXFKS1ZMI0001PF@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Thu, 12 Dec 1996 16:02:56 PST Date: Thu, 12 Dec 1996 16:04:57 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Aluminium vs Steel AN fittings (fwd) In the nuclear industry lots of valve covers are made of SS and so are >the valve bonnets. We used graphite in an isopropal alcohole solution >on the mating surfaces every time we took them on and off. However >comtaination was not a problem since this was not going to get in the >system but worked really well. Not galling on these things even though >we took some covers off every day for 30 years! > >ROY Yes, we have used molybdenum disulphide to lube SS bolts, in the past. This is the lubricant that was used on the high vacuum flanges on ion pumps, when assembled at the factory. They were subjected to a high temp bake (>350 C.). When you took them apart, the crap went everywhere. We finally persuaded the vendor to switch to silver plating on their bolts, and they have been using it ever since. It turns out to be just about as cheap as any other method, when done in sufficient quantity, and has the added bonus of looking real "cool" (until it eventually tarnishs). However, the tarnish doesn't seem to degrade the lube value, and the bolts can be reused, to some extent. Most of our stuff doesn't come apart on a regular basis, and we stress the bolts so highly on some of the vaccum flanges, that we routinely replace them with new bolts, anyway. --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu