Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

Thanks,

Errol Groff

On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff
wrote:


Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

As long as there's no welding involved, type 303.

--
Ned Simmons

"Errol Groff" wrote in message
...

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

Thanks,

Errol Groff

It seems strange that stainless is called for at all. Is there some reason
for it, or is it some designer's random idea?

Stainless is slightly less stiff than other steels; it's not particularly
strong in the likely grades you'd use; it's subject to stress-corrosion
cracking; the austenitic (300 series) grades make truly lousy bearing
surfaces; it costs more...what in the heck is the reason for it?

--
Ed Huntress

On Sun, 22 Mar 2009 16:00:12 -0500, Ned Simmons
wrote:

On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff
wrote:


Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

As long as there's no welding involved, type 303.

Indeed

Gunner

"Human nature is bad. Good is a human product*
A warped piece of wood must be steamed and forced
before it is made straight; a metal blade must be put to the whetstone
before it becomes sharp. Since the nature of people is bad, to become corrected
they must be taught by teachers and to be orderly they must acquire ritual
and moral principles."
—Sun Tzu
*

"Errol Groff" wrote in message
...

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

Thanks,

Errol Groff

If there is no spec for type, use 303. It's like the 12L14 of SS.
"303, she's for me. 304, she's a whore."

416 is fair to machine also if you need that series for heat treating, but
303 has been my favorite for machinability.
Tom

"Ed Huntress" wrote:

It seems strange that stainless is called for at all. Is there some reason
for it, or is it some designer's random idea?

Maybe that is what he had on hand?

Wes

On Sun, 22 Mar 2009 16:00:12 -0500, Ned Simmons
wrote:

On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff
wrote:


Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

As long as there's no welding involved, type 303.


Thanks guys. I will look at the plans tomorrow to see if they hint at
why S.S. is called for. My bet is that it is what the original guy
had on hand.

Errol

Wes wrote in rec.crafts.metalworking:

"Ed Huntress" wrote:

It seems strange that stainless is called for at all. Is there some
reason for it, or is it some designer's random idea?

Maybe that is what he had on hand?

Wes


More likely is the probability that the designer intended that the builder
gain experience with machining different metals.

Errol sez: "I will look at the plans tomorrow to see if they hint at
why S.S. is called for. My bet is that it is what the original guy
had on hand."

I'd almost bet on that. There couldn't be any strength considerations in engines of that small
size.

Bob Swinney

"Errol Groff" wrote in message
...
On Sun, 22 Mar 2009 16:00:12 -0500, Ned Simmons
wrote:

On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff
wrote:


Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

As long as there's no welding involved, type 303.


Thanks guys.
Errol

Connecting rods ? been a while since I looked at an engine -
I have one to make myself.
It might be they have to push through bushings and can't
get pitted or rusty.

I didn't see a spec on a lot of mine - the body was cast Iron
but one only knows what the various rods and axles are.

Martin


Ed Huntress wrote:
"Errol Groff" wrote in message
...
Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

Thanks,

Errol Groff

It seems strange that stainless is called for at all. Is there some reason
for it, or is it some designer's random idea?

Stainless is slightly less stiff than other steels; it's not particularly
strong in the likely grades you'd use; it's subject to stress-corrosion
cracking; the austenitic (300 series) grades make truly lousy bearing
surfaces; it costs more...what in the heck is the reason for it?

--
Ed Huntress

Ned Simmons wrote:
On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff
wrote:

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

As long as there's no welding involved, type 303.

Why no welding?
Never had a problem tigging 303.

cheers
T.Alan

303
Steve

"Errol Groff" wrote in message
...

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering
variety of grades.

Thanks,

Errol Groff

On Mon, 23 Mar 2009 01:10:40 -0700, "T.Alan Kraus"
wrote:

Ned Simmons wrote:


As long as there's no welding involved, type 303.

Why no welding?
Never had a problem tigging 303.

I've tigged a lot of 303 as well, but it's not recommended. The sulfur
that's added to improve machinability interferes with welding. I used
to fabricate SS marine hardware for a living and when I was welding
every day I could tell the difference between 303 and 304/316 by the
way the weld puddle behaved.

--
Ned Simmons

On Sun, 22 Mar 2009 17:16:03 -0400, Ed Huntress wrote:

"Errol Groff" wrote in message
...

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering variety
of grades.

Thanks,

Errol Groff

It seems strange that stainless is called for at all. Is there some
reason for it, or is it some designer's random idea?

Stainless is slightly less stiff than other steels; it's not
particularly strong in the likely grades you'd use; it's subject to
stress-corrosion cracking; the austenitic (300 series) grades make truly
lousy bearing surfaces; it costs more...what in the heck is the reason
for it?

Being cynical, I would guess that the original designer called it out
"'cause it's purty when it's all shined up nice".

Or he had it on hand, or he had strange notions about SS, or he wanted to
learn how to machine it, etc.

--
http://www.wescottdesign.com

On Sun, 22 Mar 2009 16:52:56 -0400, Errol Groff wrote:

Two of my students are building model hit and miss engines. The drawing
calls for stainless steel for the connecting rods but does not specify
what grade. The part will be made from .4375 diameter rod stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering variety
of grades.

Thanks,

Errol Groff

My inclination would be to use 12L14, and tell anyone who listened that
it's very low grade stainless. It'll be easier to machine, just as
strong, and it'll look a heck of a lot more authentic in an engine.

Unless, of course, the whole point of the project is to build a Really
Shiny hit-and-miss engine, of course, in which case it's fair for
appearance to take precedence over sensibility.

--
http://www.wescottdesign.com

Ned Simmons wrote:
On Mon, 23 Mar 2009 01:10:40 -0700, "T.Alan Kraus"
wrote:

Ned Simmons wrote:

As long as there's no welding involved, type 303.

Why no welding?
Never had a problem tigging 303.

I've tigged a lot of 303 as well, but it's not recommended. The sulfur
that's added to improve machinability interferes with welding. I used
to fabricate SS marine hardware for a living and when I was welding
every day I could tell the difference between 303 and 304/316 by the
way the weld puddle behaved.

I have found that a meticulous cleaning and almost polishing before
welding makes a beneficial difference in the weld puddle and finished
appearance.

cheers
T.Alan

"Tim Wescott" wrote in message
...
On Sun, 22 Mar 2009 17:16:03 -0400, Ed Huntress wrote:

"Errol Groff" wrote in message
...

Two of my students are building model hit and miss engines. The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. Will probably
order the stock from Mc Master Carr and they list a bewildering variety
of grades.

Thanks,

Errol Groff

It seems strange that stainless is called for at all. Is there some
reason for it, or is it some designer's random idea?

Stainless is slightly less stiff than other steels; it's not
particularly strong in the likely grades you'd use; it's subject to
stress-corrosion cracking; the austenitic (300 series) grades make truly
lousy bearing surfaces; it costs more...what in the heck is the reason
for it?

Being cynical, I would guess that the original designer called it out
"'cause it's purty when it's all shined up nice".

Or he had it on hand, or he had strange notions about SS, or he wanted to
learn how to machine it, etc.

--
http://www.wescottdesign.com

Yeah, we had the same thought. If it's an exposed crank and con rod, maybe
it looks flashy when it's running. g

It's unlikely that the con rod in a hit-and-miss engine is very highly
stressed. You probably could use just about any metal.

--
Ed Huntress

On Mar 23, 11:00*am, "Ed Huntress" wrote:
"Tim Wescott" wrote in message

...





On Sun, 22 Mar 2009 17:16:03 -0400, Ed Huntress wrote:

"Errol Groff" wrote in message
. ..

Two of my students are building model hit and miss engines. *The
drawing calls for stainless steel for the connecting rods but does not
specify what grade. The part will be made from .4375 diameter rod
stock.

Suggestions please on what grade to use keeping in mind that they have
no experience with S.S. so machinability is important. *Will probably
order the stock from Mc Master Carr and they list a bewildering variety
of grades.

Thanks,

Errol Groff

It seems strange that stainless is called for at all. Is there some
reason for it, or is it some designer's random idea?

Stainless is slightly less stiff than other steels; it's not
particularly strong in the likely grades you'd use; it's subject to
stress-corrosion cracking; the austenitic (300 series) grades make truly
lousy bearing surfaces; it costs more...what in the heck is the reason
for it?

Being cynical, I would guess that the original designer called it out
"'cause it's purty when it's all shined up nice".

Or he had it on hand, or he had strange notions about SS, or he wanted to
learn how to machine it, etc.

--
http://www.wescottdesign.com

Yeah, we had the same thought. If it's an exposed crank and con rod, maybe
it looks flashy when it's running. g

It's unlikely that the con rod in a hit-and-miss engine is very highly
stressed. You probably could use just about any metal.

--
Ed Huntress- Hide quoted text -

- Show quoted text -

Having gotten burned a bunch of times reverse engineering stuff; the
only way to be sure is build it out of 12L14 and find out if there is
a reason for SS.:-)