Basic design guidelines for aluminium extrusions
There are many factors that impact on designing with aluminium extrusions. It is impossible to cover these here, but to help there are a number of illustrations following which will guide you in the right direction. These are intended to inspire you with the immense flexibility aluminium in its extruded form afford.
Please contact us to discuss your specific needs in detail, you are the next generation of users, and our response will mirror the importance we place on your enquiry.
Uniform wall thickness
It is acceptable to have a range of wall thicknesses within a single profile, however uniform wall thickness make the profile easier to extrude.
It is an advantage if the internal and external wall thicknesses are similar - this decreases die stress and improves extrudability.
It is acceptable to have walls of different thicknesses where the advantage outweigh the disadvantage - eg. for strength reasons it may be best to concentrate weight away from the centre of mass.
Use of soft lines
Extrusion cannot achieve razor sharp corners. Corners need to be rounded and often 0.5-1mm is sufficient.
A design may sometimes demand sharp internal angles to enclose shapes - this is overcome by incorporating a small cut out.
Sharp tips should be avoided where possible as the tip can become wavy and uneven - should also be rounded.
Profiles with large variations in wall thickness cool unevenly. This gives a visible structural unevenness that is particularly marked after anodising.
Download (PDF) : Uniform wall thickness & Use of soft lines
Clip fit examples
Download (PDF) : Clip fit examples
Profile to Profile Hinges
A simple hinge - The ball diameter should never be less than 5mm. Including a screw port into the hinge design allows the assembly to be easily locked longitudinally using inserts and self-tapping screws.
By incorporating a 'Ball and Socket' hinge the box can be opened as shown here.
Download (PDF) : Profile to Profile Hinges
Jointing Screw Ports
Screwports can be used to join sections in many ways. They can be tapped to suit machine screws or used plain to suit self tapping screws. Small nibs can be added to help centralise the screws.
Where possible screwports should be open with a recommended opening of 60 deg. Some closed designs are possible as per the right hand section but need to be discussed fully with us.
Screws can also be placed in vertical slots as per the sections shown. Some tapping screws can be used to pierce the the base of the section if required.
Download (PDF) : Jointing Screw Ports
Extrusion design examples
Solid or hollow profiles
Solid profiles reduce die costs and are often easier to produce, so where possible, consideration should be taken to determine whether a profile needs to include cavities.
Reducing the number of cavities in a hollow profile makes it easier to extrude. this increases die stability.
Jointing clip fit
Aluminium's elasticity is highly suited to clip fits. These give far quicker assembly times than, for example, screw or welded joints.
Aluminium is still a solid metal so sufficient leg lengths must be allowed for the clip to work correctly.
Download (PDF) : Extrusion design examples (Solid or hollow profiles & Jointing clip fit)
Thread form examples
Thread form detail
|
SIZE
|
PITCH
|
A
|
B
|
C
|
|
M3
|
0.5
|
0.5
|
2.98
|
2.36
|
|
M4
|
0.7
|
0.7
|
3.98
|
3.10
|
|
M5
|
0.8
|
0.8
|
4.98
|
4.00
|
|
M6
|
1
|
1
|
5.98
|
4.75
|
|
M10
|
1.5
|
1.5
|
9.98
|
8.16
|
Download (PDF) : Thread form examples
Screw Port Data
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