Are all Aluminums the same? AKA Chinese knockoffs.

First this isn't to 'slam' anyones choice of who makes what and why you bought it.  There are plenty of good or acceptable Chinese 'knockoff' parts and 2/3rds the price of the US/Europe made products.  Then there is the US/Europe made products that are really made in China.  This is thread is to state the simple facts of grades of Aluminum and types of aluminum manufacturing process.

Most aluminum aftermarket parts are 'billed' as 6061 aluminum and CNC finish.  You see this in almost every description of every manufacture of parts.  Then they also add in Forged or Cast or my favorite is Billet.  As if Billet makes it better cause if sounds 'cooler'.

Having worked on rifles and built well over 50 AR-15s, I've educated myself on aluminum properties and manufacturing process.

Here is some food for thought before you get shell out $200 for something (lets says brake/clutch levers) that has a exact look of something on eBay that cost $39.99.  

There are reasons that $200 dollar parts cost more than $39.99 parts and it's not that the labor is cheaper or US/Europe is poking your eyes out.  You start with a grade of aluminum.  A machine rolls, forges or cast the aluminum.  A CNC machine finishes out the product.  Chinese machines are not cheaper to operate than US machines.  I guess we can argue that the Chinese person who puts the metal into the machine is cheaper but 'not that much' cheaper.  The time for each machine to operate the process is the same.  The Chinese same/same machines do not work fast.  So is the only difference that US/Europe manufactures are just poking our collective eyes out with their prices?  Do the Chinese work on razor thin margins and that's why their is such a drastic cost difference?

Lets look into grades of 6061 aluminum:

First everyone claims 6061 aluminum.  Some put -T6 at the end.  What is T6? (do I get Terminator Aluminum)  Is their a T 'less than 6'?  What does this mean?

From Wiki cause I'm not that smart:

The mechanical properties of 6061 depend greatly on the temper, or heat treatment, of the material.[3] Young's Modulus is 69 GPa (10,000 ksi) regardless of temper.[4]

6061
Annealed 6061 (6061-O temper) has maximum tensile strength no more than 120 MPa (18,000 psi), and maximum yield strength no more than 55 MPa (8,000 psi). The material has elongation (stretch before ultimate failure) of 25–30%.

6061-T4
T4 temper 6061 has an ultimate tensile strength of at least 210 MPa (30,000 psi) and yield strength of at least 110 MPa (16,000 psi). It has elongation of 16%.

6061-T6
T6 temper 6061 has an ultimate tensile strength of at least 290 MPa (42,000 psi) and yield strength of at least 240 MPa (35,000 psi). More typical values are 310 MPa (45 ksi) and 270 MPa (39 ksi), respectively.[5] In thicknesses of 6.35 mm (0.250 in) or less, it has elongation of 8% or more; in thicker sections, it has elongation of 10%. T651 temper has similar mechanical properties. The typical value for thermal conductivity for 6061-T6 at 25 °C (77 °F) is around 152 W/m K. A material data sheet [6] defines the fatigue limit under cyclic load as 97 MPa (14,000 psi) for 500,000,000 completely reversed cycles using a standard RR Moore test machine and specimen. Note that aluminium does not exhibit a well defined "knee" on its S-n graph, so there is some debate as to how many cycles equates to "infinite life". Also note the actual value of fatigue limit for an application can be dramatically affected by the conventional de-rating factors of loading, gradient, and surface finish.

As you can see above the not all 6061 is the same.  Actual 6061-T is stronger than base 6061, but 6061 will stretch more before failure.  I would venture to guess (not prove) that the $39.00 parts are 6061 vs 6061-T6.  They have to make up the cost somewhere.  Then it  could also be rejected stock or second grade stock used.


Now lets talk about the 3 process for aluminum manufacturing.  Cast, Forged and Billet.  These words are thrown around as if there is some magical properties between the three.  What are they really?


Cast Aluminum:
Cast aluminum usually refers to the method of forming a part by using a mold. By pouring molten aluminum into a 'part shaped’ mold, the part is formed when the aluminum solidifies. The casting is then removed and a CNC machine is used to finish the manufacturing process.  You can usually tell a cast product because there are casting lines in the product that the CNC machine cannot cover up or removed.

By using a casting process the manufacturer can offer a functional and economic part. (the most economical process of the three)  This process can also offer the best synthesis of mechanical properties when A380 aluminum (less pure aluminum) is used during the casting process.

While there has been less than ethical manufacturers who became known for their poor casting processes, if the part is cast properly and attention to detail is adhered to, a cast part will provide quality and reliability for most applications.

Billet Aluminum:
When a manufacturer refers a part being manufactured from billet aluminum, they are usually referring to a part that has been machined from ‘bar stock’. The ‘bar stock’ is formed by extrusion or in other words, from being rolled into a particular shape and size. A piece of the extrusion is then used by the manufacturer and machined on a CNC machine into a functional part.

Billet aluminum parts are considered to be the best looking parts. Due to the ability of the CNC machine to mill fine lines and particular designs, billet parts are known for their aesthetics. While looks do little for overall performance, some like the added 'cool factor' to the part.  They are usually the most time consuming parts to manufacture based on the other two processes.

Forged Aluminum:
Forged aluminum refers to a part that has been ‘hammered’ into forging dies to shape the aluminum into its specified contour. The aluminum is subjected to repeated force, which in turn ‘forges’ the shape of the part. Once the forging is complete, the part also is finished on a CNC machine.

A forged part is the strongest of all parts. Metallurgists agree that the forging process results in the aluminum having continuous grain characteristics, which results in the part becoming stronger than billet or cast aluminum.

As an example the time to complete a average Forged aluminum AR-15 receiver is 15 minutes vs. a Billet aluminum AR-15 receiver which takes 45 minutes. (see where cost comes in)

There are also tolerates to the cast, forge and billet process.  If a cast has air pocket in the aluminum there can be weak points in the finished product. The same goes with bar stock billet or forged if the base metals were faulty to begin with.  If the cast mold is worn out there can be loose tolerance differences in the part over time. 


Now lets move to the CNC machining process.  While these are computer controlled and one would think that they are all the same they do need to be maintained, tools heads need to be replaced and kept sharpened.  Then there are total number of CNC process to a part.  Skip a 'for looks' hole here and there.  Have the machining be less sharp to detail.  These all cut machine time and cost down.

Finally there are other parts used in parts (sorry for that sentence).  PAZZO 'knockoff' might use very cheap springs and adjustment levers in their parts compared to PAZZO manufactured.


Lastly there are different grades of anodizing for color.  Has anyone ever experiences their eBay special part's color quickly fading in the hot summer sun?



So why would there be a difference is a set of $200 billet levers vs. a $39.99 eBay special?

Well simply put they are typically using lesser grade aluminum, usually forged (even cheaper if cast) and finished with less CNC machine cuts.  The additional parts used to finished the final part are cheaper grades and quality.  Now add in the cheaper labor guy for the forge/cast process and the guy who runs the CNC machine and there you have it.  Does this mean its a bad part.....No...Could Be.....Yes....RUN FOREST RUN.  It's really hard to know from a picture and "opened the box and it looks great, buy with confidence" reviews.


So would I personally trust the eBay advertising that a set of PAZZO 'knockoff' levers are the same as the PAZZO manufactured lever?  I mean they clearly state in the advertisement 6016 and finished with CNC machine......NO.  The drastic cost difference is made up somewhere.....only you can guess what corners they cut to get to that price.  But the pictures look so.....good.
(In all honesty I deal with Chinese manufacturing and I had to watch the shipments like a Hawk.  There have been multiple times that we've rejected shipments for not meeting spec.  They knew it and tried to pass it along.  It's a game)


So does this mean that the less expensive eBay 'knockoff' parts are bad.....NO.  They can actually be quite good.  It all depends on the grade of aluminum, quality of the CNC finish and quality of the anodizing finish.  But, how do you now from a eBay picture?  The problem is these parts are mass produced.  I don't trust that they are from the same manufacture (the guys selling them to you are brokers and not manufactures) from batch to batch.  I don't trust that the aluminum grade and CNC tolerances are the same from batch to batch.  Your only real way to tell is to hope the reviews are for the batch your part came from, long term use review and actually a truthful review.  Then you can always say, "I'll take a flyer on that part and try it".  For that price..."what the hell?"

We also don't know if the US/Europe made parts are going to be good either, but it's much easier to deal with customer service from a name brand supplier rather than a import/export company who translates their response with Google translate.

I don't want to trust my life on $160 dollar savings. BUT.....that's just me.  But I have bought cheap eBay parts with great success.....so.....   Usually they were simple machined, non moving parts.  Chinese 'knockoff' GoPro accessories are quite good.  Their 'knockoff' 3M Labeled adhesives patches....not so much.  Again you got to make up that price difference somewhere.


The real point of this thread is to say don't be suckered by cheap cost and good photography.  Also do be suckered by 'the most expensive is the best'.  It's all about grade of material, type of manufacturing process and final finish when it comes to 'knockoff' Chinese metal parts.  Plastics....don't get me started.  Now there is a whole other thread.


-jm2c