I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

If these electronic chassis aren't flying around in a spacecraft, A36
should be your cheapest choice. It usually sold with the mill scale on
it and since it is rolled to final shape hot, its dimensions will vary a
little. It's commonly called "mild steel" these days. Its carbon
content can vary from about 0.15% or so to as much as 0.29%.
1018 is usually cold rolled to its finished size and if so, it is
more accurately sized, free of scale and costs more than A36, maybe 2X.
The "18" in 1018 means that its carbon content is about 0.018%.
Typically, neither of these products is considered "hardenable" by
normal processes.

1008 contains 0.08% carbon and, since that's pretty darn low, it's more
expensive to produce than the above. One big advantage of this type is
that is not as prone to work hardeneing as A36 or 1018. It is used in
application when deep drawing is needed.

12L14: the "L" stands for Lead. They put a small quantity of lead in
this steel to make it easier to machine. I haven't ever used it in
sheet goods, but it probably would be my last choice.

4130 is relatively expensive. They use it a lot in tube to make race
car roll cages. Some airplanes (maybe a LOT of airplanes) use it in
framing. I even cast some 10Kg anvils from it. Relatively high alloy.
I can't think of a good reason to use it in your application, except
that it resists cracking at welds well, I think.

Have you tried cheaper grades of aluminum? You'd want to test them.
If vibration isn't an issue, you should be able to save some bucks.
Check for "gumminess" when drilling and make sure that things don't
crack when bent.

Pete Stanaitis
-------------------



mkr5000 wrote:

I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

On Thu, 21 Aug 2008 11:01:59 -0700 (PDT), mkr5000
wrote:

I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

12L14 would be my choice. Machinists love it and consumable costs go
way down

Gunner

"Confiscating wealth from those who have earned it, inherited it,
or got lucky is never going to help 'the poor.' Poverty isn't
caused by some people having more money than others, just as obesity
isn't caused by McDonald's serving super-sized orders of French fries
Poverty, like obesity, is caused by the life choices that dictate
results." - John Tucci,

I guess the primary thing for me to be concerned with is how well it
forms. (especially at 050 thickness)

I almost always just do a 90 degree bend.....I was looking at Mc
Master Carr and they said 4130 was excellent for this but then they
didn't show the others.

4130 was half the price of 5052 aluminum but I suppose what I'm asking
is what is the most commonly used.

I know with aluminum (at least for electronics), it's 3003 or 5052.

mkr5000 wrote:
I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

4130 is used in small planes and bicycles as "chome moly" steel.

this guy goes on and on about it:

http://www.eaa1000.av.org/technicl/4130.htm

None of its merits sound like things you need for your application
though.

On Thu, 21 Aug 2008 11:01:59 -0700 (PDT), mkr5000
wrote:

I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

Others have given you some good answers... I've found aluminum often
works out cheaper in relatively small quantities when you count the
cost of the finishing required for steel, and shipping costs.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

spaco wrote:

If these electronic chassis aren't flying around in a spacecraft, A36
should be your cheapest choice. It usually sold with the mill scale on
it and since it is rolled to final shape hot, its dimensions will vary a
little. It's commonly called "mild steel" these days. Its carbon
content can vary from about 0.15% or so to as much as 0.29%.
1018 is usually cold rolled to its finished size and if so, it is
more accurately sized, free of scale and costs more than A36, maybe 2X.
The "18" in 1018 means that its carbon content is about 0.018%.

Don't you mean 0.18%?

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.


Typically, neither of these products is considered "hardenable" by
normal processes.

1008 contains 0.08% carbon and, since that's pretty darn low, it's more
expensive to produce than the above. One big advantage of this type is
that is not as prone to work hardeneing as A36 or 1018. It is used in
application when deep drawing is needed.

12L14: the "L" stands for Lead. They put a small quantity of lead in
this steel to make it easier to machine. I haven't ever used it in
sheet goods, but it probably would be my last choice.

4130 is relatively expensive. They use it a lot in tube to make race
car roll cages. Some airplanes (maybe a LOT of airplanes) use it in
framing. I even cast some 10Kg anvils from it. Relatively high alloy.
I can't think of a good reason to use it in your application, except
that it resists cracking at welds well, I think.

Have you tried cheaper grades of aluminum? You'd want to test them. If
vibration isn't an issue, you should be able to save some bucks. Check
for "gumminess" when drilling and make sure that things don't crack when
bent.

Pete Stanaitis
-------------------



mkr5000 wrote:

I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

mkr5000 wrote:
Unless I should be looking at other numbers on aluminum than 3003 and
5052, the part that emachineshop.com is quoting me is over 50% less
using the 4130 steel. (compared to 5052)

3003 and 5052 are the best alloys to bend. If your part needs
to be folded into a box or something like that, then that
material is a good choice. 2024 is very hard to bend, but in a
pinch you can anneal it along the bend line and then bend it
before it gets hard again. But, I suspect a commercial shop
won't want to mess with it. Thin 6061 and the like can also be
bent, but the thicker material will start to crack at the outer
radius. But, 2024 and 6061 are much better to machine that the
5052 and 3003.

Jon

On Aug 21, 10:02*pm, mkr5000 wrote:
Unless I should be looking at other numbers on aluminum than 3003 and
5052, the part that emachineshop.com is quoting me is over 50% less
using the 4130 steel. (compared to 5052)

Naturally, I'll stay away from 4130 if I someone can tell me I
shouldn't use it. ( ? )

So, what other numbers of aluminum should I be considering if you're
saying the part would be more inexpensive using it than steel ?

I've always heard the opposite.

If you want a lower part cost, use steel......I just never have
because of weight.

This particular part though is only about 7" x 3" and 050 thickness
would be fine -- weight isn't an issue.

You don't know the specific properties of the various alloys, which
makes me assume they aren't very critical. In which case, why
wouldn't you simply ask the shop making the parts to suggest the
alloys?

John Martin

On Aug 21, 2:01 pm, mkr5000 wrote:
I don't know why but I've been in this force of habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part done in steel and I'm
saving over 50%

What is the typical (common) grade of steel that is used in parts
where the thickness is anyhwere from 050 to 062 (all I ever use) and
the part may also have some 90 degree bends, some small holes etc.

Typical (and most inexpensive) material for electronic chassis and the
like.

I assume you mean sheet metal parts although some of those steels
imply machined bar, rod or tubing.

In small quantities aluminum usually is best overall because you don't
have to finish it, although you can paint or plate or brush or anodize
it if you want to. 6061-T6 is the most common grade for electronics, I
think because it's the strongest alloy that can be bent with few
problems, and welded. 5052 is somewhat weaker and bends to a sharper
corner without cracking. The higher performance alloys all have some
gotcha like brittleness or welding issues, the softer ones are better
for severe forming but aren't stiff enough when flat. Bud chassis
boxes are a good example, they deform easily and don't hold screws
well.

The price of aluminum seems to vary wildly between suppliers, I don't
know why. I've been quoted $60 for a 4X8 sheet from one local dealer
and over $200 from another.

"Cold Rolled Steel" or CRS around 20 to 26 gauge (~ 0.018" - 0.036")
is similar in stiffness to 0.050 or 0.062 aluminum. It's used to
repair car bodies, often in thinner gauges, and for sheet-metal
furniture and appliances. Some of its strength comes from the cold
rolling so you can't compare it directly to hot-rolled steel of
similar carbon content like A36. It's almost always plated or painted
or powder-coated even for indoor use. Some people's fingerprints will
rust it.

Hot rolled steel is the cheapest to buy and most expensive to finish.
A36 is a common type. It's easy to weld and generally used where
strength counts more than appearance.

Galvanized sheet steel is CRS with a zinc coating which protects it
from rusting, including the cut edges. I've used it for electronics
where I needed magnetic shielding and didn't have enough Mu metal. It
works about as well as aluminum but it doesn't look as good and
doesn't hold paint well. It's used for heating ducts so it's available
in small amounts, which can be a problem for metals. The largest local
dealer had a minimum order of $500 last time I checked.

There's a type of galvanized or zinc-primed or whatever steel with a
matte grey finish used for computer internals that could be the best
answer if you can find some. Common bending machines might scratch the
coating. The undersides of my SUV and truck are made of something
similar.

12L14 and its free-machining buddies make life easier for the
machinist but it rusts badly, as does chrome-moly.

A stainless steel such as 304 could be worth considering. It's more
durable than aluminum for things that will be banged around and also
doesn't need expensive finishing. Some types like 302 made decent flat
springs for no-tool panel latches.

I ask the shop for their recommendations and see if I can save money
by fitting my design to their standard practices, for instance not
calling out holes they can't punch or bends beyond their brake's
capacity. The setup is a large part of the cost for a small batch of
parts.

I set up a home shop substantially to learn materials and
manufacturing processes so I could design a $5 bracket that didn't
cost $3000 to make. Electrical engineers rarely know much about
mechanical engineering or production and too often make very expensive
design decisions. My machine tools are far too old, slow and small for
economical production - that's why they were available cheap - but
they are good enough to make a single prototype or machine a small
emergency batch of simple parts that the sheet metal shop fabricating
the job couldn't handle. Often I notice an improvement or interference
when making prototypes that I missed when drawing them.

Jim Wilkins

"mkr5000" wrote in message
...
I don't know why but I've been in this force of
habit getting some of
my small parts quoted in 5052 aluminum.

I just compared the price of a certain part
done in steel and I'm
saving over 50%

My question is this --

What is the typical (common) grade of steel
that is used in parts
where the thickness is anyhwere from 050 to
062 (all I ever use) and
the part may also have some 90 degree bends,
some small holes etc.

Typical (and most inexpensive) material for
electronic chassis and the
like.

The grade I used for the quote was 4130... but
I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer


For general chassis and sheet metal work specify
P&O. That is a standard 1018
Hot Rolled (HR) sheet metal that has been
Pickled and Oiled (P&O). Usually sold
by "gauge", you are probably looking for 16 or
18 gauge.

Sometimes specified as HRP&O-----Hot Rolled
Pickled and Oiled. It's a little bit
more expensive than regular HR sheet metal, but
well worth it for appearance.

On Thu, 21 Aug 2008 13:37:17 -0700 (PDT), mkr5000
wrote:

I guess the primary thing for me to be concerned with is how well it
forms. (especially at 050 thickness)

I almost always just do a 90 degree bend.....I was looking at Mc
Master Carr and they said 4130 was excellent for this but then they
didn't show the others.

4130 was half the price of 5052 aluminum but I suppose what I'm asking
is what is the most commonly used.

I know with aluminum (at least for electronics), it's 3003 or 5052.


3003 is about the softest grade of aluminium going.

since steel in the same thickness is about 3 times the strength of
aluminium any annealed grade of mild steel would probably do.

get your local yellow pages out. locate a sheet metal bending outfit
and ask them what the easiest grade of steel is for bending and punch
forming. that will get you first hand info.

failing that annealed 316 stainless would probably do and give you
freedom from corrosion.

Thanks folks....Jim especially, for that primer.

Yes, I'm talking about sheet and forgot to mention that I will be
painting the piece
with either a 2 part system or a powder coat.

So, I would imagine if it's painted right away -- corrrosion isn't an
issue?

The good thing about this software is you can do the part and then put
in different material choices for
an instant quote....so I'll try some of those numbers.

An 050 steel is ideal for this part because I'm using a thin magnetic
strip to hold the piece on.

It's just a 7" by 2.5" lid with (2) sharp 90 bends.

1018 -- 12L14 -- I'll try some of those numbers.

Looks like either 1018 or 12L14 is the way to go.

They're both the very same density and damn near the same price but it
says 12L14 machinability is excellent compared to 1018's "good".

?

At 050 thickness which would you use?

On Thu, 21 Aug 2008 13:19:43 -0700, Gunner Asch
wrote:


The grade I used for the quote was 4130... but I see others....

1008
1018
A36
12L14

all at at even greater savings.

THANKS for your expert answer.

12L14 would be my choice. Machinists love it and consumable costs go
way down

Gunner


Sheet metal?

Ooops...never mind.

Gunner

"Confiscating wealth from those who have earned it, inherited it,
or got lucky is never going to help 'the poor.' Poverty isn't
caused by some people having more money than others, just as obesity
isn't caused by McDonald's serving super-sized orders of French fries
Poverty, like obesity, is caused by the life choices that dictate
results." - John Tucci,