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Focus: Extrusions
Extrusions. We offer two forms of extrusions:
Extrusions
Impact Extrusions
Extrusions
Generally, aluminum billets are heated and pushed through a die/shape
(much like toothpaste) to form an extrusion.
Core Capabilities
- Standard circle size: 8", but up to 19" available
- 19.5' lengths for anodizing dipping tanks
- We deal primarily with aluminum alloys 6063, 6061, 6005, 6063,
and 6463
- We cost effectively source alloys other than 6063 when given
order quantities greater than 10 (metric) tonnes
- General tolerances are as follows, although tolerances can be
reduced depending on your needs:
- Angular: +/- 0.5 degrees
- Flatness: +/- .0019" per inch
- Twist: +/- 0.2 degrees per foot
- Straightness: 0.0047" per foot length
- Cross sectional dimension/linear: +/- 0.0154" per inch
- Wall thickness: +/- 5% of wall dimension
- Miniatures small as 1/4"
Key Advantages
- Several rolled shapes riveted together, can be replaced by a
single extruded profile resulting in higher strength while eliminating
joining costs
- Machining costs often can be reduced by extruding the desired
component to exact size and shape requirements
- Weight can be greatly decreased by putting the metal only where
it is needed (eliminating post machining costs)
- Sturdy multivoid hollow profiles are available to replace roll-formed
alternatives, often at reduced set up costs and shortened lead
times
- Improved stiffness and strength can be achieved at a lower manufacturing
cost
- Tooling for custom profiles is often substantially cheaper
Disadvantages / Challenges
- Limited materials can be extruded: only plastics and aluminum;
although there are a significant number of aluminum alloys that
can accomplish a varied number of purposes
- Aluminum as a material tends to be more expensive than other
metals
- Larger and irregular circle sizes are difficult to do
- In China, materials must be monitored carefully as some producers
will use substandard recycled materials that while reducing costs,
have impurities that cause striations and imperfections that show
up later in finishing.
Design Considerations
- Tolerances: It is important to
consider tolerances as unnecessarily tight tolerances can result
in unecessary additional expense
- Surface Finish: The ultimate
surface finish required is important to know during the material
selection process.
- Alloy: There are a wide variety
of alloys with a wide variety of properties and hardnesses, although
some of the more common ones (and generally most cost effective)
are listed above
- Circumscribing Circle Size: This
is the size of the extrusion
- Sequence of Require Manufacturing Steps:
When asking for a quote, it is often good to provide a
sample simply because we can see the sequence of steps in manufacture.
For instance because of the automation of anodizing in many extrusion
facilities, it can often be cheaper to have the extrusions anodized
and then machined / fabricated
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Impact
Extrusions
Unlike other extrusions where the billet is heated, impact extrusions
are manufactured using cold billets under high pressure. A metal
billet can be forced into just about any shape using a single stroke.
Wall thickness and part diameter are typically +/- .005". Ovality
for straight walls in F-temper can be held to within 0.001 in. per
inch of diameter when the outside diameter-to-wall ratio is less
than 15.
The following is a picture of an of impact extrusion machine of
one of our manufacturing partners:
See our following video (to come):
Key Advantages
- Because impacting is a single stroke process, it can output
quickly cutting down lead time for production
- Process is repeatable at high speed with precision part produced
to precise quality standards
- Less material is used and wasted; with little (if any) post-production
machining required
Disadvantages / Challenges
- Tooling is also significantly more expensive than normal extrusions
- Design and fabrication of tooling is an art that is still developing
in China
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& Assembly |
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