I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

What I really need is a general tutorial.

Thanks in advance.

Chuck P.

On Tue, 01 Mar 2011 10:01:58 -0800, Pilgrim wrote:

I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

What I really need is a general tutorial.

I'm not sure if you need a general tutorial, or just use what you know
and ask the occasional question here.

Steel that's recycled from scrap has hard spots, somewhere between
occasionally and often. I haven't run into any, but my dad found ball
bearings in some of his once, and I've heard reports here of someone
finding a tap -- still identifiable as to diameter and thread -- buried
in some angle iron.

I suspect it's just something you have to accept.

--
http://www.wescottdesign.com

"Tim Wescott" wrote in message
...
On Tue, 01 Mar 2011 10:01:58 -0800, Pilgrim wrote:

I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

What I really need is a general tutorial.

I'm not sure if you need a general tutorial, or just use what you know
and ask the occasional question here.

Steel that's recycled from scrap has hard spots, somewhere between
occasionally and often. I haven't run into any, but my dad found ball
bearings in some of his once, and I've heard reports here of someone
finding a tap -- still identifiable as to diameter and thread -- buried
in some angle iron.

You may be thinking of me. We found a tap in a piece of steel -- I no longer
remember the grade, but it was graded barstock -- back around 1974. I've
mentioned it here a couple of times. It's hell on endmills. g

But you're right, the junk is mostly in recycled steel, particularly in
structural grades. I have never put a piece of A36 on a machine tool and I
doubt if I ever will.

The fact that a piece of steel is an AISI or SAE grade is not a guarentee
that it will be free of high-temperature junk, like cutting tools and such,
but it's pretty good assurance that the steel is homogonized, and won't have
varying amounts of carbon. The only sure way to avoid both is to buy
electric remelt -- electroslag or vacuum-arc. But that's almost exclusively
tool steel grades, except for some special military and aircraft materials,
and it costs like the devil.

--
Ed Huntress


I suspect it's just something you have to accept.

--
http://www.wescottdesign.com

On Tue, 01 Mar 2011 10:01:58 -0800, Pilgrim
wrote:

I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.

This ****es me off when it happens.rare enough to just keep using
mystery metal. Often enough to have to always have a spare blade on
hand.

What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

Cold rolled is generally what you get, by far the most common. Has a
smooth finish, unlike hot rolled with a thin layer of crappy stuff. I
use cold rolled for 99% of my steel needs.


If you need high performance steel for a special application, ask when
you have the need. I find McMaster Carr has a good selection and
description of many specialty steels.

Karl

You can see the exceptions in the other replies, but the only material that
I've used which fairly consistently had a number of very hard spots in it,
was OBF old bed frame angle.

The OBF stuff doesn't MIG weld well, either, IME. I've had deeply penetrated
welds pull out completely, to the root.

Some stainless seel alloys work harden during cutting, and can dull a HSS
cutting tool edge instantly if feed force is paused, but other common steels
don't.

I always use a reliable cutting lubricant, not oil or some other improvised
fluid, and generally keep feeding pressure steady 'till the cutting is
completed.

Any new hot rolled that I've bought in recent years, still has the scale on
it. I'll grind the scale away for weld areas, otherwise I just clean it
well, and paint.
Diluted muriatic/hydrochloric acid (available in many retail stores for
etching concrete, etc) is effective at removing the scale when the parts can
be submerged in the acid solution.
After treating with the diluted acid, I generally rinse with baking soda
water, then fresh water rinse, quickly/force dry and apply oil (new 30W).

The same acid treatment generally works well for rusty steel and cast iron
parts, although with light rust, I often treat similarly with a diluted
phosphoric acid/metal etch solution, then dry as mentioned previously.

--
WB
..........


"Pilgrim" wrote in message
news
I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

What I really need is a general tutorial.

Thanks in advance.

Chuck P.

Ed Huntress wrote:

But you're right, the junk is mostly in recycled steel, particularly in
structural grades. I have never put a piece of A36 on a machine tool and I
doubt if I ever will.

The fact that a piece of steel is an AISI or SAE grade is not a guarentee
that it will be free of high-temperature junk, like cutting tools and such,
but it's pretty good assurance that the steel is homogonized, and won't have
varying amounts of carbon. The only sure way to avoid both is to buy
electric remelt -- electroslag or vacuum-arc. But that's almost exclusively
tool steel grades, except for some special military and aircraft materials,
and it costs like the devil.

Back to Chuck's question, what would you
recommend for general fixture and machine
building? Looking over McMaster, O1 seems
to be pretty versatile, available in
decent sized bars and about twice as
expensive as A36.

I've had good luck threading and making shafts
out of 303.

On 2011-03-02, Jim Stewart wrote:
Ed Huntress wrote:

But you're right, the junk is mostly in recycled steel, particularly in
structural grades. I have never put a piece of A36 on a machine tool and I
doubt if I ever will.

The fact that a piece of steel is an AISI or SAE grade is not a guarentee
that it will be free of high-temperature junk, like cutting tools and such,
but it's pretty good assurance that the steel is homogonized, and won't have
varying amounts of carbon. The only sure way to avoid both is to buy
electric remelt -- electroslag or vacuum-arc. But that's almost exclusively
tool steel grades, except for some special military and aircraft materials,
and it costs like the devil.

Back to Chuck's question, what would you
recommend for general fixture and machine
building? Looking over McMaster, O1 seems
to be pretty versatile, available in
decent sized bars and about twice as
expensive as A36.

I do a lot with 1018.

i

I've had good luck threading and making shafts
out of 303.

"Jim Stewart" wrote in message
...
Ed Huntress wrote:

But you're right, the junk is mostly in recycled steel, particularly in
structural grades. I have never put a piece of A36 on a machine tool and
I
doubt if I ever will.

The fact that a piece of steel is an AISI or SAE grade is not a guarentee
that it will be free of high-temperature junk, like cutting tools and
such,
but it's pretty good assurance that the steel is homogonized, and won't
have
varying amounts of carbon. The only sure way to avoid both is to buy
electric remelt -- electroslag or vacuum-arc. But that's almost
exclusively
tool steel grades, except for some special military and aircraft
materials,
and it costs like the devil.

Back to Chuck's question, what would you
recommend for general fixture and machine
building? Looking over McMaster, O1 seems
to be pretty versatile, available in
decent sized bars and about twice as
expensive as A36.

I've had good luck threading and making shafts
out of 303.

I'm not the guy to ask on that one, Jim. I rarely do any milling these days,
and when I have made fixtures, I usually used 2024 aluminum tooling plate or
other shapes in medium-hardness aluminum.

But I can mention some general principles. From the OP's question it doesn't
sound like he needs to harden the pieces, so for free machining and good
surface finishes, you can't beat 12L14 (Ledloy; C12L14). But it costs a lot
more than the scrap he's trying to use, so that may be a problem.

O1 and other oil-hardening tool steel grades are good if you need to harden
the steel, although for fixture parts, you have to avoid sharp corners and
wide differences in thickness. It hardens easily but it will crack in
difficult sections like that. For commercial work, A1 or other air-hardening
grades are preferred because they're very safe to harden and they distort
the least.

I can't think of any reason to use 1018 or other basic carbon steels over
12L14, unless you can get it a lot cheaper. If you're going to case-harden
anything, 12L14 can be case hardened, as can most any low- to medium-carbon
steel. 1018 or 1020 also will give you a good case without significant
distortion.

But what's the job? If you need hardness for wear resistance somewhere, the
picture changes. If you don't, and if you don't need to worry about
temperature stability, aluminum is lighter and much easier to machine.

--
Ed Huntress

On Wed, 2 Mar 2011 14:43:30 -0500, "Ed Huntress"
wrote:


I can't think of any reason to use 1018 or other basic carbon steels over
12L14, unless you can get it a lot cheaper. If you're going to case-harden
anything, 12L14 can be case hardened, as can most any low- to medium-carbon
steel. 1018 or 1020 also will give you a good case without significant
distortion.

A few other relevant facts regarding 1018 vs. 12L14:

12L14 is only available in round, square and hex; 1018 is available in
those shapes, plus rectangles in finely graduated sizes from 1/8x1/4
up to at least 4x8

1018 is easy to weld; welding 12L14 is not recommended

There's not much price difference between the two.

The cold finishing processes leaves 1018 with internal stresses that
can cause nasty surprises if you don't keep that fact in mind,
especially when making slender and/or asymmetrical parts.

--
Ned Simmons

On 2011-03-02, Ed Huntress wrote:
I can't think of any reason to use 1018 or other basic carbon steels over
12L14, unless you can get it a lot cheaper. If you're going to case-harden
anything, 12L14 can be case hardened, as can most any low- to medium-carbon
steel. 1018 or 1020 also will give you a good case without significant
distortion.

Except you cannot weld 12L14.

i

"Ignoramus13991" wrote in message
...
On 2011-03-02, Ed Huntress wrote:
I can't think of any reason to use 1018 or other basic carbon steels over
12L14, unless you can get it a lot cheaper. If you're going to
case-harden
anything, 12L14 can be case hardened, as can most any low- to
medium-carbon
steel. 1018 or 1020 also will give you a good case without significant
distortion.

Except you cannot weld 12L14.

i

Well, you can, but as Ned said, it's not recommended. You get lead migration
and unless you're good, you'll get enough of it to cause trouble.

But, yes, that would be a good reason to choose 1018 over 12L14.

--
Ed Huntress

Karl Townsend wrote:
On Tue, 01 Mar 2011 10:01:58 -0800,
wrote:

I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.

This ****es me off when it happens.rare enough to just keep using
mystery metal. Often enough to have to always have a spare blade on
hand.

What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

Cold rolled is generally what you get, by far the most common. Has a
smooth finish, unlike hot rolled with a thin layer of crappy stuff. I
use cold rolled for 99% of my steel needs.


If you need high performance steel for a special application, ask when
you have the need. I find McMaster Carr has a good selection and
description of many specialty steels.

Karl


Mcmaster Carr has a good selection of metals but they are not too cheap
when you need a reasonable quantity. Burgon steel has more reasonable
prices but maybe a little slower on delivery.

http://www.burgon.com/

I use Pennsylvania Steel Co. for cold finish round bar and stainless
303. They seem to have good pricing and since I buy quite a bit I get
free delivery but they will also ship UPS if the length and weight in
under the UPS limits.

http://www.pasteel.com/



John

On 2011-03-03, John wrote:
Karl Townsend wrote:
On Tue, 01 Mar 2011 10:01:58 -0800,
wrote:

I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.

This ****es me off when it happens.rare enough to just keep using
mystery metal. Often enough to have to always have a spare blade on
hand.

What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

Cold rolled is generally what you get, by far the most common. Has a
smooth finish, unlike hot rolled with a thin layer of crappy stuff. I
use cold rolled for 99% of my steel needs.


If you need high performance steel for a special application, ask when
you have the need. I find McMaster Carr has a good selection and
description of many specialty steels.

Karl


Mcmaster Carr has a good selection of metals but they are not too cheap
when you need a reasonable quantity. Burgon steel has more reasonable
prices but maybe a little slower on delivery.

http://www.burgon.com/

I use Pennsylvania Steel Co. for cold finish round bar and stainless
303. They seem to have good pricing and since I buy quite a bit I get
free delivery but they will also ship UPS if the length and weight in
under the UPS limits.

http://www.pasteel.com/

I buy from speedy Metals in Wisconsin (speedymetals.com). No RFQs
necessary, good online prices, custom cutting (saves a lot of time),
good shipping costs, relatively quick processing.

i

On Mar 1, 11:01*am, Pilgrim wrote:
I have been away from metal working for a long time. Last I worked there
were [for the casual user] hot rolled, cold rolled, and drill rod.
Having just ruined a band saw blade on a piece from the junk box that
tested ok with a file, seemed to have hard spots.What type of steel
should one use for ordinary fixturing? Do some of the newer hot rolled
have a smooth finish like the old cold rolled? What steels are likely to
have hard spots?

What I really need is a general tutorial.

Thanks in advance.

Chuck P.

Regardless of general usage, hot-rolled and cold-rolled are FINISHES,
not steel GRADES. You can get various grades of steel in both
finishes. If you just need a low carbon steel, 1018 is available in
both finishes. Hot rolled can be had in either scaled condition or
pickled and polished, which is closer to the cold-rolled finish. If
you want to do extensive machining and don't want to machine all
surfaces to avoid warpage, hot-rolled is highly recommended. Cold-
rolled stock has a lot of stress locked up in it, would need annealing
to relieve it before machining, which leaves you with about the same
material and surface condition as hot-rolled.

If you want to make some sort of cutting tools, one of the tool steel
grades would be what you want. Low-carbon steel can be case-hardened
if you need easy machining combined with a wear surface.

As far as what steel to use where, Carpenter Steel had a book on
their tool steels and where to use them, title escapes me right at the
moment.

As far as fixtures, you could use continuous cast iron shapes on up,
just depends on what you're doing and what kind of load it has to
endure.

Stan