difference between extruded aluminum and sheet aluminum

hey guys can anyone tell me or point me in the right direction in how i could identify extruded aluminum and sheet aluminum? For example, crutches, bigger umbrellas, heater cores, window screens, etc? thanks.

Originally Posted by THEDANIMAL

hey guys can anyone tell me or point me in the right direction in how i could identify extruded aluminum and sheet aluminum? For example, crutches, bigger umbrellas, heater cores, window screens, etc? thanks.

Just look at the profile. If it was formed by being pushed through a die, it's extruded. If it was folded or creased to its shape, it's sheet.

Originally Posted by mthomasdev

Parker,

I would disagree with you. Most of the crutches that I get are extrusions (if cleaned properly). Large umbrellas (yard type), the pole is usually extrusions (have to clean) and the upper parts can also be. Window screens can go either way. Glass windows are almost always extrusions.

I Personally have always known crutches as sheet. Ill inspect them closer if I get some more.
You might be right about some yard umbrellas. My yard would take em as sheet or mixed, I wont spend the time to clean the paint off of them.

Some aluminum tubing is welded, some is rolled sheet and crimped, and some is extruded. Crimped is obvious....example: old style tv and radio antennas. Welded tubing is usually a lot less obvious. Ever look at those old style aluminum patio chairs? There's no sign of welds, but all the ends of the tubes are capped and welded. Pretty safe bet that the tubing is too. Extruded aluminum tubing usually has tiny, hair thin lines, running the length of the tubing. You have to look extremely close to notice this.

all sheet by me as well. Extruded can be window frames, some heavy alum patio chairs and such.

Originally Posted by olddude

Heat sinks are extruded no matter what your yard tries to tell you. they are 6061 I believe, the heavy ones are aqlu/cu

I have to tell the scale guy that they are extruded every time. But they still don't believe me, even after inspecting them. They are happy to pay me a few more cents per lbs. in the end though.

Originally Posted by ParkerFlyer4

I Personally have always known crutches as sheet. Ill inspect them closer if I get some more.
You might be right about some yard umbrellas. My yard would take em as sheet or mixed, I wont spend the time to clean the paint off of them.

All the yards that I use that have an extrusion category, you don't need to clean paint for them to go as extrusions.

many aluminum heat sinks are extruded, for sure not all. Buying at my scale I have seen more than a few heat sinks that are aluminum plate with fins in them like this:
Progressive Stamped Heat Sink Project Highlights

Product Description	This Aluminum Heat Sink Fin Assembly was developed for a Projection Television application
Capabilities Applied/Processes	Development Develop a Cost Effective Heat Sink for Maximum Heat Dissipation Stamping Custom Mechanical Assembly
Equipment Used to Manufacture Part	Minster 150 Ton Brown Boggs 200 Ton Tooling Progressive Dies 8 Stations for Base Plates 10 Stations for Fins
Overall Part Dimensions	Base Plate: Material Thickness: .065" Length: 6.5" Width: 3.5" Height: 1.0" Unfolded Fin Length: 18" Folded Fin: Material Thickness: .020" Length: 5.75" Width: 3.25" Height: 1.50"
Tightest Tolerances	Base Plate: ±.005" Folded Fin: ±.00075"
Material Used	Aluminum
Estimated Part Weight	.35 lbs
Features/Benefits	Custom Staking Method of Incompatible Material Thicknesses Eliminates Glue Seal & More Expensive Techniques
In Process Testing/Inspection Performed	In-Process Real-time SPC of Critical Dimensions CMM Measurement Strength Testing on Stakes Cleanliness Sediment Testing Dimensional Results Reporting Control Plan Process Flow Diagram Failure Mode and Effects Analysis (FMEA) Gage Repeatability Reproducibility Variable Data Report Raw Material Chemical Composition Results MSDS - Material Safety & Data Report/Substances and Materials
Industry for Use	Consumer Electronics
Volume	600,000 Pieces
Packaging	Special Pack Thermal-Formed Packing Trays Anti-Static
Lead Time	Tooling: 14 Weeks Production Parts: 6 Weeks
Delivery Location	Tenessee Mexico
Standards Met	Customer supplied print, 2D CAD Drawing
Product Name	Heat Sink Fin Assembly

I have also seen a lot of small heat sinks that are injection molded or cast.

Originally Posted by mthomasdev

I think this thread just shows everyone how different things are from one yard to the next and how important it is to now how each of your yards classify items and what they pay for them in order to maximize profits.

I have 3 yards that get 99% of my material. One large multi location yard only has clean and dirty aluminum (and aluminum rims). My main yard closest to my house has many categories, but not Mixed Low Copper Clip, otherwise know as MLC or Clip. They do have a Solids category that may be the same a MLC. Another yard about 40 minutes away has numerous categories. I'm not up there enough to have a full understanding of how they grade every category. I have sold computer heat sinks there and most times gotten extrusions. I did get MLC once for them.

As New has indicated, yards will purchase as one category and upgrade to another, as her umbrella explanation shows. My advice to everyone is to ask alot of questions at your yards. Learn the way they grade and what you need to do to upgrade these items yourself.

Man iam lucky I guess. My yard only differentiate' s cans (higher price) everything else goes in same tub, same price.

But having worked at that yard I know they separate it themselves.

Extrusion is defined as the following.

The process of generating a surface by translating a plane curve parallel to some line is called extrusion, and surfaces that are generated by extrusion are called cylindrical surfaces . A familiar example of the surface of a right circular cylinder which can be generated by translating a circle parallel to the axis of the cylinder. The following theorem provides basic information about graphing equations in two variables in 3-space.
Theorem: An equation that contains only two of the variables x, y, and z, represent a cylindrical surface in an xyz coordinate system. The surface can be obtained by graphing the equation in the coordinate plane of two variables that appear in the equation and then translating that graph parallel to the axis of the missing variable.

I hope this clears things up.
I only get to answer someone like this about every 5 years, so I could not resist

the yards by me take heatsinks as old hard sheet- i know im being ripped off bcos they're def extrusion.
i dont know whats their reason for this.

i wont be surprised of they sell them as extrusion after buying it from us.

Originally Posted by msmoorad

the yards by me take heatsinks as old hard sheet- i know im being ripped off bcos they're def extrusion.
i dont know whats their reason for this.

i wont be surprised of they sell them as extrusion after buying it from us.

My yard refuses to accept that crutches are extruded. I guess because SOME are not extruded that means for them that NONE are extruded.