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Help! Edge Distance Rule

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Rob Acker

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Aug 16, 1996, 3:00:00 AM8/16/96
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00nzwi...@bsuvc.bsu.edu wrote:

>My memory is suddenly untrustworthy and I can't recall the rule for minimum
>edge distance for rivet holes in aluminum. Radius/Diameter statements and
>statements of distance from edge of metal to edge of hole versus distance from
>edge of metal to center of hole have rolled together in my head. Incredibly,
>none of my reference books mention this subject.--

>Nyal Z. Williams
>00nzwi...@bsuvc.bsu.edu

Minimum edge distance is 2 x rivet diameter, measured from center of
hole to edge.

Rob (RV-6Q).

Tom Betka

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Aug 17, 1996, 3:00:00 AM8/17/96
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On 6 Aug 96 10:03:32 -0500, 00nzwi...@bsuvc.bsu.edu wrote:

>My memory is suddenly untrustworthy and I can't recall the rule for minimum
>edge distance for rivet holes in aluminum. Radius/Diameter statements and
>statements of distance from edge of metal to edge of hole versus distance from
>edge of metal to center of hole have rolled together in my head. Incredibly,
>none of my reference books mention this subject.--
>
>
>
>Nyal Z. Williams
>00nzwi...@bsuvc.bsu.edu

Nyal,

I don't have my AC 43.13 handy, but I think the minimum edge distance
is 2D and pitch is 4D for single-row rivets. (D=rivet diameter). Of
course, it's different for double or greater numbers of rows. For
example, for a 4-row "patch" or repair, the minimum edge distance is
3D. I'll check for sure this weekend and get back to you if it's any
different. I haven't looked it up for a while... You can email me
directly at: tcb...@students.wisc.edu

Tom Betka


Ronald James Wanttaja

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Aug 17, 1996, 3:00:00 AM8/17/96
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On 6 Aug 96 10:03:32 -0500, 00nzwi...@bsuvc.bsu.edu wrote:
>
>My memory is suddenly untrustworthy and I can't recall the rule for minimum
>edge distance for rivet holes in aluminum. Radius/Diameter statements and
>statements of distance from edge of metal to edge of hole versus distance from
>edge of metal to center of hole have rolled together in my head. Incredibly,
>none of my reference books mention this subject.--

The minimum spacing (center-to-center) is three times the rivet diameter
between holes, and 2 times the diameter from the center of the hole to any
edge. If you're doing double row or multiple row riveting, slightly
different requriements come into play. See AC 43-13A, Chapter 2,
section 3, para. 99. _Kitplane Constuction_ includes a diagram and
table, page 179 in the first edition and page 195 in the second. I
included the same diagram/table in a KITPLANES magazine "Shopsheet" a
few months back.

Ron Wanttaja
want...@halcyon.com
http://www.halcyon.com/wanttaja/

John Ammeter

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Aug 19, 1996, 3:00:00 AM8/19/96
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In article <4v2ci0$f...@sjx-ixn6.ix.netcom.com> r.a...@ix.netcom.com (Rob Acker) writes:
>Path: news.seanet.com!solaris.cc.vt.edu!homer.alpha.net!mvb.saic.com!unogate2!news.service.uci.edu!usc!howland.erols.net!netcom.com!netcom.net.uk!ix.netcom.com!news
>From: r.a...@ix.netcom.com (Rob Acker)
>Newsgroups: rec.aviation.homebuilt
>Subject: Re: Help! Edge Distance Rule
>Date: Fri, 16 Aug 1996 17:55:05 GMT
>Organization: Netcom
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>Message-ID: <4v2ci0$f...@sjx-ixn6.ix.netcom.com>
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>X-NETCOM-Date: Fri Aug 16 10:53:04 AM PDT 1996


>00nzwi...@bsuvc.bsu.edu wrote:

>>My memory is suddenly untrustworthy and I can't recall the rule for minimum
>>edge distance for rivet holes in aluminum. Radius/Diameter statements and
>>statements of distance from edge of metal to edge of hole versus distance from
>>edge of metal to center of hole have rolled together in my head. Incredibly,
>>none of my reference books mention this subject.--

>>Nyal Z. Williams
>>00nzwi...@bsuvc.bsu.edu

>Minimum edge distance is 2 x rivet diameter, measured from center of
>hole to edge.

>Rob (RV-6Q).

Or, if simpler, 1 1/2 x rivet diameter measured from the edge of the hole.
Sounds obvious but I think it is easier to measure; was for me, anyway.

John (RV-6)

Dean Mueller

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Aug 23, 1996, 3:00:00 AM8/23/96
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Edge distance is twice the diameter of the hole

00nzwi...@bsuvc.bsu.edu wrote in article
<1996Aug6...@orion.bsuvc.bsu.edu>...


> My memory is suddenly untrustworthy and I can't recall the rule for
minimum

> edge distance for rivet holes in aluminum. --


Dan Sullivan

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Aug 24, 1996, 3:00:00 AM8/24/96
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Everyone has correctly indicated that the minimum edge distance for a
Universal Head rivet (AN-470 or MS20470) is 2D, or two times the
diameter of the rivet shank. The recommended rivet spacing is 4D-12D
(depending upon how much room you have). Distance between rows of
rivets is usually 1/2 of rivet spacing.

What has been omitted is that for Countersunk Rivets (AN 426 or
MS20426), the minimum edge distance is actually 2-1/2D, to allow for the
material lost during the countersinking operation.

If you're setting your edge distance for a countersunk rivet at 2D, you
might be setting yourself up for future problems, especially if it's a
single row.

Dan Sullivan, A&P
--
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Sullivan Educational Enterprises ++++ Raleigh, North Carolina
Bright Ideas in Educational Consulting and Technician Training

919-233-7171 Phone
919-233-8911 Fax
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Craig C.

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Aug 27, 1996, 3:00:00 AM8/27/96
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Dan Sullivan <s...@ntrnet.net> wrote:

Some snipped here...


The recommended rivet spacing is 4D-12D
>(depending upon how much room you have). Distance between rows of
>rivets is usually 1/2 of rivet spacing.

This realy depends on the pattern laid out and approved by the
engineer. I pulled the manufacturing standards for where I used to
work and it specifies 3D spacing on row, column and stagger spacing
unless something else is called out.

>What has been omitted is that for Countersunk Rivets (AN 426 or
>MS20426), the minimum edge distance is actually 2-1/2D, to allow for the
>material lost during the countersinking operation.

Again, depends on the engineering...ours called out for E.D. of 2D
period...doesn't matter if it is for countersink, protruding head, or
blind rivets. The only thing that makes any change is the rivets being
either corrosion resistant steel or Monel....

>If you're setting your edge distance for a countersunk rivet at 2D, you
>might be setting yourself up for future problems, especially if it's a
>single row.

As long as your hole preperation is good and you are not using a
straight line rivet pattern in an area of high loads, and you don't
overdrive the rivets, you will most likely never see any cracking
problem.


Just to satisfy my curiosity, I looked at the Inspection Minimums we
had for the largest rivet we ever used. For a .500 dia rivet, we had a
minimum E.D. of only .750" on material of .125" or thicker..
BTW...those .500 rivets are a bear to shoot and buck too...


Craig


HNEUBERT

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Aug 28, 1996, 3:00:00 AM8/28/96
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Test measurements of varying edge distances show that an e/D of 2.0 gives
approximately 80% of the value when e/D is much larger, greater than 4.
The e/D of 2.0 rule comes about from practical considerations, primarily
the width of rib flanges riveted to skins. The edge distance of the rib
is the critical factor.

H Neubert

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