[AT] Heat treating tractor parts

Thu Mar 17 15:52:29 PST 2005

While everyone is on this subject, I have a related question that I would
like some
advice, help, or opinion on.  Have a flail mower for a Cub that uses about
70 or so
L shaped blades on it.  The long part of the L is about 5" and the bottom is
about 1".
They are made of steel that is 1/8" thick and 3/4" wide.  I haven't been
able to find
a source for these so it appears that I must find some stock and make them.
Need about
a dozen but will make more if I have to have any made.

What kind of steel should these things be made of?

The originals appear to have been sharpened on both sides before they were
bent into
the L shape.  I have found some 1/8th x 3/4 bar stock here locally but it
appears to be
relatively soft.  Not sure it would last very long as a blade on that flail
mower.

Thanks!

Howard Weeks
Harlem, GA

----- Original Message -----
From: "Grant Weir" <grantweird at hotmail.com>
To: <at at lists.antique-tractor.com>
Sent: Thursday, March 17, 2005 1:00 PM
Subject: RE: [AT] Heat treating tractor parts

Hi Dean,

   I think Brett has the right idea here - use material that is already
heat-treated.  Our shop uses the stuff all the time instead of spending
money on small batch heat-treating.  The common designation is 4140 HTSR or
4340 HTSR.  The "HTSR" stands for "Heat Treated and Stress Relieved".   4340
is a little tougher than 4140 but close enough not to matter.  Ask for
"HTSR".  I don't think you want Case Hardening as it only hardens the outer
0.03" or so and leaves the center soft.  This is fine for a wear surface but
does little to improve strength.

   Also, if you use 4140 or 4340 you can tell your customers that the parts
are made from "billet chrome-moly steel dude!".  As soon as you say "billet"
or "chrome moly" everyone will think you really know what your talking about
and want to buy your stuff.  No kidding!

Grant Weir
Saskatoon, SK.
Canada

>From: "Brett Phillips" <bphillip at shentel.net>
>Reply-To: Antique tractor email discussion group
><at at lists.antique-tractor.com>
>To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
>Subject: RE: [AT] Heat treating tractor parts
>Date: Thu, 17 Mar 2005 09:33:32 -0500
>
>Dean:
>
> Jim has some good questions regarding the design of the shaft.  The nature
>of the load may also have some bearing on the material selection.  Is this
>an impact load, or more of a constant load?  For an impact type load, you
>should look for something that will remain ductile and tough, even after
>heat treating (which can be done many ways according to the desired
>result).
> If you're looking for something more economical than a custom heat
>treatment, you might consider something like an AISI 4142 pre-heat-treated
>steel.  This material is a 4140 steel alloy which has been stress relieved,
>and then heat treated to 28-32 on the Rockwell "C" scale.  This leaves you
>with a tough material that can still be machined with common practices, yet
>it has a tensile strength of about 150,000 psi, and very good impact
>properties.  Compare this with something like AISI C1018 (plain ole cold
>rolled squeal, er steel) at about 80,000 psi tensile, or cold rolled 4140
>at
>~100,000 psi.
>Just another option.
>
>Regards,
>Brett Phillips
>
>
>-----Original Message-----
>From: at-bounces at lists.antique-tractor.com
>[mailto:at-bounces at lists.antique-tractor.com]On Behalf Of Jim and Lyn
>Evans
>Sent: Thursday, March 17, 2005 6:36 AM
>To: 'Antique tractor email discussion group'
>Subject: RE: [AT] Heat treating tractor parts
>
>
>How much load does the shaft have to take?  Are there any grooves or
>shoulders (other than the threads) that might cause some stress risers?
>
>Jim
>
>-----Original Message-----
>From: at-bounces at lists.antique-tractor.com
>[mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Dean VP
>Sent: Wednesday, March 16, 2005 8:20 PM
>To: at at lists.antique-tractor.com
>Subject: [AT] Heat treating tractor parts
>
>I would like some help from experienced metal fabricators.  I would like to
>know how much increased durability/strength "heat treating" a 1" round
>steel
>shaft, threaded at both ends would offer.  The shaft is primarily under
>tensile forces only but the forces are severe in actual application. The
>threaded ends of the rods are RH and LH threads and are inserted into
>threaded cast forks at each end. Kind of like a turnbuckle.
>
>I am trying to have these fabricated at a local machine shop however, in
>order to heat treat economically they need to be heat treated in batches of
>50 each which is a larger quantity than what I would like to produce at one
>time. If not done in a relatively large batch the heat treating becomes a
>too significant part of the overall manufacturing cost.
>
>What am I gaining in this application by heat treating or what am I losing
>by not doing so?
>
>I have been advised to use 4340 steel, heat treated RC40 or 1018 steel not
>heat treated.  Help, I'm not a metallurgist. These would be for resale so
>there is an inherent responsibility to do it right.
>
>Any help is appreciated.
>
>Dean A. Van Peursem
>Snohomish, WA 98290
>
>I'm a walking storeroom of facts..... I've just lost the key to the
>storeroom door
>
>
>www.deerelegacy.com
>
>http://members.cox.net/classicweb/email.htm
>
>
>
>
>
>
>_______________________________________________
>AT mailing list
>http://www.antique-tractor.com/mailman/listinfo/at
>
>_______________________________________________
>AT mailing list
>http://www.antique-tractor.com/mailman/listinfo/at
>
>
>
>_______________________________________________
>AT mailing list
>http://www.antique-tractor.com/mailman/listinfo/at

_______________________________________________
AT mailing list
http://www.antique-tractor.com/mailman/listinfo/at