BCoffman79

Knife blade scrap steel around the farm

Recommended Posts

My name is Brian Coffman and I'm new to bladesmithhing. I've made 5-6 knives in the last 2 months mainly rebar knives. RR spike knives. And a few from flat stock we have at work. I work in a rebar fabrication shop mainly I use the scrap to make knives but I'd like to find some good steel around the farm that I could forge a knife that would have and maintain a solid sharp edge. Any suggestions would be appreciated. I'm currently talking with a few mechanics to get some cool spring or leaf springs but would like to find stuff from cutting discs or bushhogs to forge good quality knives. I live in Wilmore Ky so if anyone is close and wouldn't care to show me a few things or share some tips I would really appreciate it. I have 4 wonderful boys ages 9 10 15 & 17 that forging is something we can do together besides football. Hunting. And fishing. Just an idea of what my setup is a propane forge with single xl burner and railroad track anvil I've shaped out. I appreciate any advice given 

15481952650582593858841971660417.jpg

15481953181061837533530202819291.jpg

Share this post


Link to post
Share on other sites

A lot of old agricultural steel is good medium to high carbon alloys.  However some of the newer disks and brush hog blades are now a boron alloy that does not harden appropriately for blades. So do you have access to the old stuff often abandoned in place along fence rows or???  Can you spark test for carbon content? 

A lot of the steel involved in pulling of tillage equipment may be 1075-1080 as well.  I'm working up my nerve to ask my landlord about a 2.5" square by 14' long bar that a bunch of plow points are mounted to...out along the fence row along the back of the property.  a lifetime + of hammer stock if it tests as HC.

"Step by Step Knifemaking"  showed a lot of old steel the author used for his blades.

Share this post


Link to post
Share on other sites

Yes sir all the equipment we have is 10-15 years old or more. Thank you very much for the response. I really appreciate the advice. Will definitely look up step by step knife making 

Share this post


Link to post
Share on other sites
On 1/22/2019 at 5:16 PM, BCoffman79 said:

I work in a rebar fabrication shop mainly I use the scrap to make knives

As in a rebar manufacturing plant? If so can you find out specs on the rebar?

Share this post


Link to post
Share on other sites
4 hours ago, Benona blacksmith said:

As in a rebar manufacturing plant? If so can you find out specs on the rebar?

The rebar comes to us in 40'-60' lengths sizes ranging from #4 =1/2" to #11 2" most is unweldable steel that we use for building cages and mat's to bending whatever shape our customers require. The coils we use in certain machines are weldable steel. I know for sure its 60 grade rebar. But tomorrow I'll go talk to the salesman and see if he will print me out the heat numbers and grade for the welded and non weldable rebar. I made a knife out of the weldable rebar for 2 of my boys when I first started and surprisingly they took and held a good sharp edge from quenching in warm water, dishwashing liquid, & Epsom

 

4 hours ago, BIGGUNDOCTOR said:

Look for coil and leaf springs.

Stopped at a mechanic shop today of a guy I know. Found quick struts with coil springs on them still, got 15-20 of them and hes going to keep coil springs and leaf springs for me from here on out. Pretty sure they are 1060 and they have thin black coating around them that I sanded off 

That one pic was my first forge. 4" steel pipe kaowool and a hole for small propane torch to supply the heat. Got er done though20181225_150844.thumb.jpg.744513141a88d9aff648b7b11ac76c49.jpg

20181224_224206.jpg

Share this post


Link to post
Share on other sites

Here in the States rebar is hot dog or chorizo metal, ya just don't know what is in it.

 

I would not spend many hours on an item made from it.

If your mechanic friend has a strut press, have him remove them for you. They can seriously injure you if done wrong.

As cars go, tapered roller bearings used in axles, spindles, and differentials. Transmission bearings, and older hood and trunk lid flat wound springs will give you some other options.

Now, having said that. Invest in some reading time. We have a couple of bladesmithing authors here; Steve Sells, and JPH.  Learn from those that have been there and done that.

10-15 years may not be old enough to miss the new alloys for brush hog blades. There is one company that supplies many of the OEM's with them. It takes a very specialized heat treatment to get the best out of it.

Share this post


Link to post
Share on other sites
23 hours ago, Benona blacksmith said:

As in a rebar manufacturing plant? If so can you find out specs on the rebar?

 

 

 

Paper 01.jpg

paper 02.jpg

Share this post


Link to post
Share on other sites

So the top 3 are all "mild steel" less than .3% C (.26, .25, .25)

The bottom was in the lower medium carbon steel range  .41%   I've seen axes that were made with .5% but not in general knives.

 

Share this post


Link to post
Share on other sites

Automotive coil and leaf springs are often made from 5160 with about .6% C and other elements that help in hardening.  Makes good large blades.  Knives are often made using steels that are above the eutectic (about .76% C)  Higher C allows you to get more carbides for edge longevity. It also increase brittleness.  There is NO one perfect alloy for making blades!

May I commend to your attention "Introduction to Knifemaking", Steve Sells, (who is a member here) and "The Complete Bladesmith", J.P. Hrisoulas, (who also is a member here.)

Share this post


Link to post
Share on other sites

May I ask one more thing? Would it be possible to get some spec sheets from a couple more batches as your work receives them so we can do some comparative research to see how close of tolerances rebar has?

Share this post


Link to post
Share on other sites

remember that rebar is a structural rating not any type of alloy content, just because one manufacturer does it one way does not mean any other do, or even that this one keeps it that way for long

Share this post


Link to post
Share on other sites

Sorry just saw this. The next truck that comes in I will try to get the specs. Sorry new to site. Learning all the buttons and tabs. 

Share this post


Link to post
Share on other sites

Don't sweat it BC, using the forum is a learning curve almost as long as blacksmithing. You're doing fine.

Benona: What's your interest in rebar? It's really iffy, especially for a beginning smith, just learning the basics is challenging enough without having to learn to evaluate an inconsistent material. Performance specification means that so long as rebar has the minimum tensile strength, bending moment and rebound it's good. It can exceed any or all specs and often does, it's generally not carefully composed nor well mixed meaning the C and alloy can change unpredictably sometimes in inches.

There ARE different grades of rebar say for prestressed bridge beams or atomic power plants that is made to better quality controls.

In general though rebar is bottom of the barrel for the smith. Sometime though it's all there is and you use the best you have.

Frosty The Lucky.

Share this post


Link to post
Share on other sites
6 hours ago, Frosty said:

it's generally not carefully composed nor well mixed meaning the C and alloy can change unpredictably sometimes in inches

This is what sparked my interest. I have read this so many times I wanna know if it is really true. I talked with a metallurgist not too long ago and he told me that rebar has WAY closer tolerances than people give it credit for. It's not just melted and poured and hope for the best. Also a foundry keeps records for pretty much forever because when a bridge or building or other concrete structure fails the first thing that is looked at is the rebar and its properties. We have an opportunity to see rebar spec sheets and evaluate it...... I want to take advantage and see for myself.

Share this post


Link to post
Share on other sites

So I followed up with my friend that is a metallurgist and he has confirmed that rebar is really tightly controlled here in the United states and it would be impossible for an alloy and carbon content to change within inches let alone within an entire pour. So in all.... what the spec sheet says you can count on the entire batch to have those specifications and properties.

Share this post


Link to post
Share on other sites

Interesting. Still, the specs given on that sheet still disqualify that rebar from making decent knives. Frankly, the only projects that I think are good for rebar are structural (e.g., bracing the legs of my striking anvil) or decorative (e.g., rebar bottle openers for contractors who supply me with scrap A36).

Share this post


Link to post
Share on other sites

I'll accept your statements about rebar, at least for use in certain types of structures: bridges, buildings, etc. are specced higher grades. I'll even ease off on the inconsistency I've experienced in the past. 

If I'm wrong I'm wrong I'll admit it.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Honestly the only thing I have used rebar for is in concrete and a few times to weld handles on a billet but it is quite rough to hold onto for extended periods of time without gloves. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now