Mark Montgomery
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If you are truely interested in bevel washers as noted at http://www.portlandbolt.com/products/washers/malleable_beveled_washer.html , these are used on surfaces that are not perpendicular to the hole axis. Examples are I-beams and other structural steel members. Also, castings typically have a draft angle which can be compensated for by counterboring or the use of a bevel washer.
Are you possibly referring to a Belville washer? If so, here is a link to information to get you started: http://en.wikipedia.org/wiki/Belleville_washer
Also, here is a video on washers. It is long but well worth the time. http://www.nord-lock.com/default.asp?url=51.16.37
14 years ago
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Everest
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Thank you for the information, but its not what i was looking for. I'm looking for any reference/information on a beveled or bevel washer. The inside hole of the washer is not at a 90 degree angle but at a 45 degree angle. Do to the manufacturing of the bolt head is not 90 degrees at the shaft of the bolt, I believe"using common sense" the bevel washer allows space of the bolt head so the washer is not crush.
I'm interested in this because its part of an aircraft and im trying to find the right guidance or reference to provided to my supervisors that this is the right way of installing this washer.
Here's an image of a bevel washer
http://www.ereplacementparts.com/images/part_1610114015.gif
Thanks, Everest
14 years ago
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Mark Montgomery
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Could this be what you are looking for? There's a nice diagram on the first link: http://www.carrlane.com/Catalog/index.cfm/27825071F0B221118070C1C513E111D081B0006280B1713050245221E0107070F1A3C3B2853504558
http://www.valtrainc.com/Tooling/sphwash.htm
14 years ago
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Niel
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If the Bevel Washer shown is used in an Airplane then here should be specific information in the maintenance manual as to the correct installation of the part.
Have you tried to contact the manufacturer of the airplane or if the airplane is now longer in normal service searched on the internet for the maintenance manuals for that aircraft?
Because the part could easily be put in backward there should be a maintenance notice describing the correct installation.
Niel Leon
Community Developer - Engineer.com
14 years ago
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Everest
ASKED BY
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There is a maintenance manual for the installation of the bolt and washer but no guidance on which way the washer goes. And this is the correct washer as it is in the IPB. So, Im putting in a change so others know how to install the washer in correctly. I was just looking for any reference to back my change so that it does not get kick back to me for lack of evidence/proof. I would also like to see the proof(since I was told by a guy years ago) that if it was installed backward that it would cause the removal of the bolt to be harder. I search all over the internet and aircraft general maintenance manuals and found nothing. I think I just have to go to the college research it, I know the engineering department has a library, so I'll see about take some time to go check it out. Thanks for helping me out with this.
14 years ago
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Mark Montgomery
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Take a look at these. You might be able to track down a MIL spec or something based on the "AC950" notation on these washers.
http://www.faa.gov/library/manuals/aircraft/amt_handbook/media/FAA-8083-30_Ch05.pdf (see page 50)
http://rgl.faa.gov/REGULATORY_AND_GUIDANCE_LIBRARY/RGADVISORYCIRCULAR.NSF/0/a563729e3daac121862569f1005f80f1/$FILE/Chap%206_pg%20121-171.pdf (see page 11).pdf
14 years ago
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Niel
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I can see technical reasons to place the washer in either direction
Flair side against the skin of the air craft spread the load and prevent edge loading on the hole where the washer is installed.
Flair side against the nut to compensate for any internal chamfer may be on the bolt head.
Now which one is correct in this application?
Also are you sure it is not one side of a spherical washer pair like Mark has pointed out as a possibility?
Niel
14 years ago
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pmac10
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Neil, i think you have hit the nail on the head so to speak, i have used these washers on inflight refueling probe mounting, the bevel on the washer mates to a corresponding profile on the underside of the bolthead, dont know the exact reasoning behind it (the bolts were safety wirelocked also) but you would be shocked by the number of fitters didnt know there was a difference in fitting them
14 years ago
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Niel
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Pmac:
If the bolt does have such a feature then it is there as minimize stress concentrations at the bolt head and reduce fatigue failure. A sharp corner at the head / shaft connection result in a stress concentration. To reduce the stress razor a chamfer is included.
This is especially important for bolts that are made from high strength materials or bolt used in high vibration environments like on aircraft.
Niel
14 years ago
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pmac10
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niel
i should have known that as i always ask for a small radii when machining shafts from one diameter to another, and thinking back, these washers had a curvature rather than a bevel.
think the original question is answered though.
14 years ago
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