I apologize for an actual on-topic post but I'm stumped.

I once had an old engineering book that had info on edge margins for
holes.

The edge margins for thin sheet are well known and easily found,
but I'm having no luck locating the tables for Lugs.

As I best recall the difference is the relative thickness of the
metal being bolted or riveted.

Can anyone help me out here?

Richard

Try he http://trs.nis.nasa.gov/archive/0000...1/asm-B200.pdf

Or, if desperate to the point of spending money, he
http://www.aiaa.org/content.cfm?page...97&g ID=45326


David Merrill


"Richard Lamb" wrote in message
. net...
I apologize for an actual on-topic post but I'm stumped.

I once had an old engineering book that had info on edge margins for
holes.

The edge margins for thin sheet are well known and easily found,
but I'm having no luck locating the tables for Lugs.

As I best recall the difference is the relative thickness of the
metal being bolted or riveted.

Can anyone help me out here?

Richard

David Merrill wrote:
Try he http://trs.nis.nasa.gov/archive/0000...1/asm-B200.pdf

Or, if desperate to the point of spending money, he
http://www.aiaa.org/content.cfm?page...97&g ID=45326


David Merrill



I followed the NASA link. It _may_ answer the question -
if I can interpret it correctly?

Thanks, David. That was quick too!

Richard

"Richard Lamb" wrote in message
. net...

I apologize for an actual on-topic post but I'm stumped.

I once had an old engineering book that had info on edge margins for
holes.

The edge margins for thin sheet are well known and easily found,
but I'm having no luck locating the tables for Lugs.

As I best recall the difference is the relative thickness of the
metal being bolted or riveted.

Can anyone help me out here?

Richard

Hey Richard,

You did not specify, and I assume that you were interested in smaller
than this, but I stumbled across the following in a small handbook I
picked up the other day, called "IPT's Metal Trades Handbook". It
was in the section on Structural Steel

___________________________________
Safe Edge Distances for Holes In Structurals
----------------------------------------------------------------------
Hole size | Edge Distance
9/32 | 3/8
11/32 | 1/2
7/16 | 5/8
9/16 | 7/8
11/16 | 1-1/8
13/16 | 1-1/4
15/16 | 1-1/2
1-1/16 | 1-3/4
--------------------------------------------------------------------
Table #64. Structural Edge Distances

Take care.

Brian Lawson,
Bothwell, Ontario.

ps.......DID you find what you wanted, and if so, where?



XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Sun, 19 Feb 2006 02:55:16 GMT, Richard Lamb
wrote:

David Merrill wrote:
Try he http://trs.nis.nasa.gov/archive/0000...1/asm-B200.pdf

Or, if desperate to the point of spending money, he
http://www.aiaa.org/content.cfm?page...97&g ID=45326


David Merrill



I followed the NASA link. It _may_ answer the question -
if I can interpret it correctly?

Thanks, David. That was quick too!

Richard

"Richard Lamb" wrote in message
. net...

I apologize for an actual on-topic post but I'm stumped.

I once had an old engineering book that had info on edge margins for
holes.

The edge margins for thin sheet are well known and easily found,
but I'm having no luck locating the tables for Lugs.

As I best recall the difference is the relative thickness of the
metal being bolted or riveted.

Can anyone help me out here?

Richard

Brian Lawson wrote:
Hey Richard,

You did not specify, and I assume that you were interested in smaller
than this, but I stumbled across the following in a small handbook I
picked up the other day, called "IPT's Metal Trades Handbook". It
was in the section on Structural Steel

___________________________________
Safe Edge Distances for Holes In Structurals
----------------------------------------------------------------------
Hole size | Edge Distance
9/32 | 3/8
11/32 | 1/2
7/16 | 5/8
9/16 | 7/8
11/16 | 1-1/8
13/16 | 1-1/4
15/16 | 1-1/2
1-1/16 | 1-3/4
--------------------------------------------------------------------
Table #64. Structural Edge Distances

Take care.

Brian Lawson,
Bothwell, Ontario.

ps.......DID you find what you wanted, and if so, where?



XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Sun, 19 Feb 2006 02:55:16 GMT, Richard Lamb
wrote:


David Merrill wrote:

Try he http://trs.nis.nasa.gov/archive/0000...1/asm-B200.pdf

Or, if desperate to the point of spending money, he
http://www.aiaa.org/content.cfm?page...97&g ID=45326


David Merrill


I think so, David.

The argument is that the rivets in my airframe don't quite meet the edge
margin for thin sheet. This truss is built from 3/4x3/4x1/8" extruded 6061-T6
angle material, using 1/8" to 3/16" AD470 (driven) rivets. This is 5 times
the normal .025 sheet thickness - with two pieces making 1/4" grip length.

The aero purist insist is is going to crack at the rivets (although with over
70 airplanes flying for over 20 years - ain't happened yet!)

Even in an accident, the angles bend some, but no broken rivets.

I was trying to find something that would explain this, and the NASA document
seems to help. Edge margin for lugs seems to be defined in part by the
thickness of the part - with thicker parts requiring smaller margins.

That table above, if I'm reading it right, seems to agree(?)

Anyway, that's what the question was about.

Got a spare clue?

Richard

Pardon me please for missing the correct name, BRIAN!