# Aluminum 6061-t6 VS  1100  machinability question.



## Ken from ontario (Jan 18, 2017)

I just ordered a 6 foot length of  1.5"x 1.5" Aluminum 6061-t6 for machining small parts with my mini mill, so far I've been using  scrap pieces I had brought from work many years ago some were angles, some 3/8" flat pieces of cut-offs but have no idea  what type of aluminum alloy they were.
I searched the net and based on this site, Aluminum alloy 1100 has "Excellent Formability / Workability" but so does 6061.
My question to those of you who have machined different types of Aluminum is,  how did you like AL6061  and /or 1100? is one significantly  better than the other  in terms of machinability? will a newbie to working with aluminum  see a  difference?
I also priced a small sheet of plastic called delrin thinking plastic would be easier on the small mill(motor/cutting tools) but the price of 24"x 48" x1" was close to $580  so I'm back with Aluminum for now.
Please share your comments and your thoughts.
Ken


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## francist (Jan 18, 2017)

Can't speak to the 1100 aluminum question, but with regards to plastics I've always been able to get off-cuts from the fabrication shops so it's a lot less prohibitive than pricing a full sheet. Victoria is not a big manufacturing centre by any stretch, but there's still two plastic fab shops within a mile and half of me and both have scrap boxes by the door with bits and bobs of stuff. There's got to be something within range of where you are. Great way to get a feel for a type of plastic without breaking the bank right off the bat. 

-frank


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## Ken from ontario (Jan 18, 2017)

Hi Frank, I did ask the  metal wholesaler if they have scrap plastic remnants/off cuts  which they didn't but they always let me have metal scraps for welding and stuff, never thought of looking for plastic fab shops near me.
The next best thing in plastic is UHMW, even the dollar stores  sell cutting boards but I have heard they create a huge mess when planing or machining.


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## Nogoingback (Jan 18, 2017)

In part, the decision to choose one material instead of another depends on what sort of part you're making.  6061T6 is very commonly used in all sorts of applications and is known to machine well, can be 
welded and has good structural properties.  It's also widely available.   Have a look at this website:  www.*onlinemetals*.com.  They sell all kinds of metals and plastics, and have an online guide
to aluminum that should get you started.   Delrin is  reasonably strong for plastic and machines easily, but of course it doesn't have the strength of aluminum.


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## ddickey (Jan 19, 2017)

6262 is nice to work with also.


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## rgray (Jan 19, 2017)

Not sure on 1100 but I ended up with some 2 series aluminum years ago. 2100 possibly.
it was very soft and gummy compared to other aluminums I had around. 
Not sure if that was all in the heat treat or lack of it or not.
Should probably try a small piece and see if it is usable before ordering much quantity.


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## Ken from ontario (Jan 19, 2017)

Thank you all for your comments so far.
Russ, thanks for your relpy. I did my research before ordering  the 6061 but it was done  mainly by reading websites peddling their products, what I'm after is the actual practical experience by members , that in my opinion is more valuable  .
You mentioned 2100, to be honest I'm not familiar with all these alloys but it reminded me , I did have a flat Aluminum bar  a while back that when I tried to cut it, ( with a cutting wheel/grinder) it produced some gummy material as if it was melting, now after reading your post about the 2100 I'm thinking that was probably what I was cutting.

I'm just learning what different alloys of aluminum are , what's available and what they actually do when  machined. the site I linked in my first post gives some information about 6061 and other types of material:
https://www.metalsupermarkets.com/7-things-consider-choosing-aluminum-grade/


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## ChipsAlloy! (Jan 19, 2017)

Hello, you will not regret the 6061 choice for your small mill. It is the alloy we mainly use at my job and I was granted  access to the scrap bins so I do use a lot of it at home. Its not gummy and machines nicely. It can also be welded nicely as long as you have the power to do it and spend the right time in preparation.

 For plastics well, im not sure about uhmw for a general purpose material. So far I found it a bit messy and it also is not as fun to machine as delrin or even better (IMO) HDPE. The last two have very nice properties and are a joy to machine with some HSS cutters dedicated to plastics only. The UHMW  I use as well but mostly for wear resistant parts. (wear strips, roller chain tensionners etc.).

I can understand why some shops are dedicated to plastics only.. such a joy!

Have fun!


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## seanb (Jan 20, 2017)

Pure aluminum is very gummy/hard to machine but it works great when doing extrusions/ forming. That's why cans and window frames are made with 1100, Not too good when you are casting but usually cheap or free.


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## Ken from ontario (Jan 20, 2017)

Today I machined a small piece of the AL6061 and I really liked what I saw, it was  a joy to machine,was a bit on the soft side though, when I lightly tapped on in in the vise, the hammer  left a few marks on the surface,even though the one I was using has a very small brass head,  but it cleaned up very nicely, I now have 60" of this Aluminum and have no inhibition using it  for other projects.
Sean, I'm glad I didn't get the 1100,I would have returned it if I had, it's good to know what applications it is good for ,thanks .
Thank you all for your inputs.


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## Wreck™Wreck (Jan 20, 2017)

Formability  and cut machining ease are not the same thing.

Forming parts requires a high ductility, wire drawing, bending, deep drawing, spinning and die forming come to mind. Many of these alloys are difficult when used in cut machining not under ideal conditions.

6061 T6 has about the best properties/cost that a hobbyist could ever want, there are however some alloys that are less available and machine equally as well or better yet will cost more. 7075 and 2024 T6 are good choices as far as machining.


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## Rustrp (Mar 30, 2017)

Ken from ontario said:


> I just ordered a 6 foot length of  1.5"x 1.5" Aluminum 6061-t6 for machining small parts with my mini mill, so far I've been using  scrap pieces I had brought from work many years ago some were angles, some 3/8" flat pieces of cut-offs but have no idea  what type of aluminum alloy they were.
> I searched the net and based on this site, Aluminum alloy 1100 has "Excellent Formability / Workability" but so does 6061.
> My question to those of you who have machined different types of Aluminum is,  how did you like AL6061  and /or 1100? is one significantly  better than the other  in terms of machinability? will a newbie to working with aluminum  see a  difference?
> I also priced a small sheet of plastic called delrin thinking plastic would be easier on the small mill(motor/cutting tools) but the price of 24"x 48" x1" was close to $580  so I'm back with Aluminum for now.
> ...


I wanted to add a couple of things on the aluminum. The 1100 is commercially pure (14K-24K psi tensile strength) and the 6061 is an alloy (20K-42K psi tensile strength) with a chemical composition that allows for heat treating. I think it's beneficial for every person to take a quick peek into the properties of the material they're choosing to work with, if they choose the career field or work at it as hobby. There's enough information on material available today that a person doesn't need a metallurgy class or degree. Off the hip I'll say metals have been alloyed for thousands of years and the alloys make the difference in the purpose of the metal and since you mentioned it, the same is happening with plastic. I think gold being worked and used is dated back  30K-40K years BC. then along came copper bronze iron and our modern steel production. Aluminum is an easy metal to work and work with and while the commercial grades do not have the extensive range of alloys as steel, they do cover a wide sector of the market in their use. Unless the material is special ordered by a manufacturer, the heat treatable aluminum grades leave the mill heat treated to the level they are usually intended for market use. With that said, they are not suitable for heavy forming operations but are readily machinable. 2024 and 7075 have tensile strengths equal to mild steel.-Russ


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## ghostdncr (Mar 31, 2017)

At a company I used to work for, we regularly made a small transducer component very similar in size and shape to a sewing thimble. This has been my only exposure to machining 1100-series aluminum, and it was used strictly due to some electrical property needed for the transducer assembly to work properly. I hated that stuff. Like trying to turn stale peanut butter!

No one within the company had ever developed a good cutting procedure for that part, but I was finally able to get something workable pieced together. I remember grinding several sets of HSS lathe tools specifically for that job, and I think the best had considerably sharper angles than conventional aluminum-turning tools. Used either WD40 or aluminum Tap Magic for cutting fluid. Very light cuts at high speed I believe. I am NOT a fan of 1100, but there's more than a little possibility I was doing something (or several somethings) wrong in my approach to working it.

I've always enjoyed machining the 6000-series aluminums. Being primarily alloyed with magnesium, these grades play nice and generally produce what I consider middle-of-the-road characteristics. Tough enough for most applications, easy enough to machine that most beginners can figure them out with relative ease. 

The 7000-series material has come to be my favorite. Alloyed with zinc, this stuff is strong, heavy, machines more like mild steel, and can hold very fine detail. I grin just a little when I open a new print packet and see "7075 AL" typed in the material box...


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## cvairwerks (Mar 31, 2017)

1100 is almost soft enough to machine with a wooden stick.....


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## RandyM (Mar 31, 2017)

Here is an Aluminum Properties Guide

May help clear up some questions.


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## Doodle (Aug 11, 2017)

Ken from ontario said:


> I just ordered a 6 foot length of  1.5"x 1.5" Aluminum 6061-t6 for machining small parts with my mini mill, so far I've been using  scrap pieces I had brought from work many years ago some were angles, some 3/8" flat pieces of cut-offs but have no idea  what type of aluminum alloy they were.
> I searched the net and based on this site, Aluminum alloy 1100 has "Excellent Formability / Workability" but so does 6061.
> My question to those of you who have machined different types of Aluminum is,  how did you like AL6061  and /or 1100? is one significantly  better than the other  in terms of machinability? will a newbie to working with aluminum  see a  difference?
> I also priced a small sheet of plastic called delrin thinking plastic would be easier on the small mill(motor/cutting tools) but the price of 24"x 48" x1" was close to $580  so I'm back with Aluminum for now.
> ...



I use primarily 6061 on mini mill and lathe. I get most of it from McMaster Carr as it is really inexpensive in small lengths of different sized plate, rod, and bar. On the mill I use 2 flute end mills HSS, I do light cuts to not load the mill and keep the speed 1/4 to 1/2 throttle. On the lathe I use carbide inserts on the Harbor Freight $20 tooling kit, has several cutter holders, several inserts, and the tool to screw the inserts in place with. I keep the speed low and take my time. I get really nice finish, the material is very durable. I use it at work for alignment fixtures.  You can use a light oil with cutting like WD40, kerosene but I don't find it needed. Delrin (Nylon 66) is really nice to work with.


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## FanMan (Aug 13, 2017)

Delrin and Nylon are NOT the same thing.  They're both trade names from Dupont and have some similar characteristics, but Delrin is acetal (polyoxymethylene) while nylon is a polyamide resin.  Delrin has more inherent lubricity than nylon, making it well suited for bearings, etc.

Re aluminum, there are many, many alloys out there, but 6061 is the most common as it's "good enough" for most applications, easy to machine, and weldable.  It's cheap because they make so much of it.  6063 is also common, and often used for architectural purposes as it's somewhat more corrosion resistant than 6062.  Of the 2000 series, 2024 is the most common... higher strength, but not weldable, often found in sheet form for aircraft structures. 7000 series (e.g. 7075) is still stronger, but subject to stress corrosion cracking.


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## KMoffett (Aug 14, 2017)

My quick go to reference for Aluminum alloys: https://www.mcmaster.com/#about-aluminum/=18xvv7c

Ken


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## epanzella (Aug 15, 2017)

6061 machines great. It's my go-to alloy for machining aluminum.


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