Perforating Specifications
Defining basic perforation patterns
Requirements which are not covered by or do not conform to
these criteria should always be specified by submitting a drawing
of the full sheet, with unperforated margins clearly marked,
together with details of the required perforated pattern and
its orientation relative to the sheet.
Introduction
The basic perforation patterns most commonly used can be defined
by determining the following criteria:
1. Hole shape - Hole size - Orientation of hole relative to
edge of plate
2. Hole pattern - Distance between hole centres (pitch)
3. Orientation of pattern relative to edge of plate
4. Plain (unperforated) margins between holes and edges of
sheet
Terminology
Length (of sheet/plate) = will always be taken
to be the longer of the two dimensions
Width or height (of sheet/plate) = the shorter
of the two dimensions
Pitch = measurement from centreline of one
hole to centreline of next hole
Bridge = measurement from edge of one hole
to edge of adjacent hole - ie the amount of solid material between
holes
1. Hole shape - Hole size - Orientation of hole
The following standard hole shapes can be supplied:
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Round
- specify diameter 'A'
|
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Square at 45 degrees
45 degrees to edge of sheet
- specify width 'A' across flats
|
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Obround
(Round ended slot)
parallel to width of sheet
- specify overall length 'A' and
width 'B'
|
 |
Rectangle
(Rectangular slot)
parallel to width of sheet
- specify length 'A' and width
'B'
|
 |
Obround
(Round ended slot)
parallel to length of sheet
- specify overall length 'A' and
width ëBí
|
 |
Rectangle
(Rectangular slot)
parallel to length of sheet
- specify length 'A' and width
'B'
|
 |
Square
- specify width 'A' across flats
|
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Hexagon
- specify width 'A' across flats
|
(Note that stock tooling for square and rectangular holes
often has radiused corners to aid production)
2. Hole pattern - Hole centres (pitch)
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Square pattern
- specify pitch 'X' parallel to
length and width of sheet
|
 |
Rectangular pattern
- specify pitch 'X' parallel to
length of sheet,
and pitch 'Y' parallel to width
of sheet
|
 |
Staggered pattern (60 degree)
- specify pitch 'X' parallel to
straight rows of holes
|
 |
Staggered pattern (45 degree)
- specify pitch 'X' parallel to
straight rows of holes
|
 |
Staggered pattern (any angle)
- specify pitch ëXí
parallel to length of sheet,
and pitch 'Y' parallel to width
of sheet
|
 |
Staggered pattern (slots in
rows end to end)
- specify pitch 'X' parallel to
length of sheet,
and pitch 'Y' parallel to width
of sheet
|
 |
Staggered pattern (slots in
rows side by side)
- specify pitch 'X' parallel to
length of sheet,
and pitch 'Y' parallel to width
of sheet
|
3. Orientation of pattern relative to edge of plate
 |
Rectangular pattern
- longer pitch parallel to length
of sheet
|
 |
Rectangular pattern
- longer pitch parallel to width
of sheet
|
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Staggered pattern (including 60 degree)
- straight rows parallel to length
of sheet
|
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Staggered pattern (including 60 degree)
- straight rows parallel to width
of sheet
|
 |
Staggered pattern
- slots parallel to width of sheet
|
 |
Staggered pattern
- slots parallel to length of sheet
|
4. Plain margins
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Margins along the length
(margins along the long sides)
- specify dimension(s) 'A' &
'B'
Margins across the width
(margins along the short sides)
- specify dimension(s) 'Cí
& 'D'
|
|
custom perforated panels
