Brandonk42

Tempering a Railroad Spike

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Hello!

I'm very new to the blacksmithing world. This site rocks and thank you for those whom have already helped me out!

I just have a quick question about tempering a RR spike knife. Could someone be kind enough to explain to me the property technique?

Thanks so much!

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no you cant HT a spike, sorry read about heat treating and you will understand that one needs at least 35 points of carbon to harden a steel

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Buy quenching in Rob Gunter's "Super Quench" you can toughen up a HC RR Spike; but it's not really in the league of proper knife hardness's in my opinion.

The HC spikes are spec'd to never exceed the boundary between mild steel and medium steel. The rail clips, funny ampersand looking things, spec out quite a bit higher and would make a decent blade as well as most automobile coil and leaf springs.

RR Spike knives seem to be wildly popular but they are like the dancing bear---the wonder is not how well it dances but that it dances at all!

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Thanks guys!

I did some reading and I definitely see what you are driving at. They are HC spikes but even those don't appear to have a high enough cabon content to make a "good" knife. I have a ton of these things so maybe I could try something else with them.

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HC does NOT mean high carbon steel, I have not found out who started that false rumor....

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no you cant HT a spike, sorry read about heat treating and you will understand that one needs at least 35 points of carbon to harden a steel

No disrespect meant to a fellow electrician, but I'm going to get nitpicky here.

There is no magic number above which steel will harden or below which it will not. The maximum attainable hardness of a given piece of steel versus the carbon content forms a curve on the graph. The more carbon available, the more martensite which can be formed. (Up to a point, anyway. Maximum attainable hardness levels out around 60 or 65 points. Retained austenite can actually diminish maximum attainable hardness at carbon levels beyond this.) Run an internet image search with the terms "carbon" and "hardness" and a few renditions of this graph will show up. Or look in chapter 6 of Principles of Heat Treatment of Steel by Krauss for a very good graph.

A spike or other bit of steel with 20 points of carbon can indeed be hardened. But no, it won't get as hard as another bit of steel with 30 points.


I have a ton of these things so maybe I could try something else with them.

Hot work punches. Bottle openers. Sculptures of funny little people. Tent stakes. Cobras.

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Letter openers instead of knives.

You can also weld a proper high carbon bit in and make a good knife that way. Not a simple task at that point though.

Phil

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His question was about a knife, while I am sure one can make a knife shaped object from balsa wood, I would not consider that a good edge for a blade either. This is the blade section, so therefore anything here refers to blades.

Normally, open questions about blades and hardening, refer to their edge holding ability, so in this context RR spikes are not able to be hardened enough to make them usable as a real blade due to low carbon content, I have steeled edges to make them usable, but this is much easier to do when in spike form than after being thinned to blade thickness, but maybe I am just "nit picking" now too :)

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In theory, with a severe quench, 0.3% carbon steel could achieve RC 55, which I would consider to be in the lower end of the knife range. Wear resistance would be poor. I would not call it a serious knife by modern standards, but it's not exactly useless. Probably beats most of what passed for knives through a great deal of human history.

0.2% carbon steel can achieve only the upper 40s RC. (That matches up well with Robb Gunter's results of up to RC 48 in 1018 quenched in a lye solution, since 1018 can contain up to 20 points of carbon.) It'd be better than a sharp stick, and a lot tougher than a piece of obsidian . . .

My buddy with the spectrometer has run a couple spikes, and they turned out to have 0.25% and 0.3% C.

But if you're going to do the work to forge a spike into a knife, for a few bucks you could use a real high carbon steel, do about the same amount of work, and produce a serious blade.

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Hello:

As someone who has made about 1,000 or so of these they can be hardened to a degree..well hard enough to take a decent edge and hold it for a while but you need to quench in ice cold (lierally) brine solution of sodium hydroxide and salt, something that most folks really are not that keen on doing.

No need to draw back a temper as these are not brittle..at least I have never had one break on me yet.

It's more of a "novelty" than anything but they can make an OK knife but the whole idea is "Wow..that was a rail road spike" is the driving force in play...

JPH

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HC does NOT mean high carbon, I have not found out who started that false rumor....


I have always heard that HC means high carbon or higher carbon. Not in the sense of a high carbon steel but higher carbon than other spikes. Since you claim it does not, would you care to enlighten us with what it does mean? I don't want to continue false information and am occasionally asked about it, I'd like to impart the truth.

ron

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You are correct. They are not high carbon in the general sense of "high carbon steel." They are "high carbon" in the world of railroad spikes, as spelled out below.

http://notcooperedu.org/~stevansk/Keystone/AREMA/Proceed/1_05p02.pdf

Section 2.2 SPECIFICATIONS FOR HIGH-CARBON STEEL TRACK SPIKES1 (1968)
 
2.2.1 SCOPE (1968)

a. These specifications cover high-carbon steel track spikes.

 

b. A supplementary requirement, Article 2.2.14, of an optional nature is provided. It shall apply only when specified by the purchaser.

 

 

AREMA Manual for Railway Engineering 5-2-5

 

2.2.2 PROCESS (1968)

 

The steel shall be made by one or more of the following processes: open-hearth, acid-bessemer, electric-furnace, basic-oxygen.

 

2.2.3 CHEMICAL COMPOSITION (1968)

 

The steel shall conform to the following requirements as to chemical composition:

 

 

Carbon, min, percent:

Acid-bessemer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 0.20

 

Other processes (Article 2.2.2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30

 

Copper, when specified under supplementary requirementArticle 2.2.14, min, percent . . ..  . . . . 0.20

 

 

2.2.4 LADLE ANALYSIS (1968)

 

a. A determination for carbon and copper, when copper is specified, shall be made of each heat of steel. This analysis shall be made from a test ingot taken during the pouring of the heat. The chemical composition thus determined shall be reported to the purchaser or his representative, and shall conform to the requirements specified in Article 2.2.3.

 

b. When ladle analysis cannot be furnished, the manufacturer shall submit a report of the chemical analysis made on three spikes selected at random from each 10-ton lot.

 

 

2.2.5 TENSILE PROPERTIES (1968)

 

The manufacturer may, at his option, substitute tension tests for the chemical analysis specified in

 

Article 2.2.3, in which case the finished spikes shall conform to the following requirements as to tensile properties:

 

Tensile strength, min, psi. . . . . . . . . . . . 70,000

 

Yield point, min, psi . . . . . . . . . . . . . . . . 0.5 tensile strength

 

Elongation in 2 in., min, percent . . . . . . 25

 

 

2.2.6 BENDING PROPERTIES (1968)

 

a. The body of a full-size finished spike shall stand being bent cold through 120 degrees around a pin, the diameter of which is not greater than the thickness of the spike without cracking on the outside of the bent portion.

 

b. The head of a full-size finished spike shall stand being bent backwards to an angle of 55 degrees with the line of the face of the spike, without cracking on the outside of the bent portion.

 

 

2.2.7 NUMBER OF TESTS (1968)

 

a. When the option in Article 2.2.5 is exercised, one tension test shall be made from each 10-ton lot or fraction thereof.

 

b. One bend test of each kind specified in Article 2.2.6a and Article 2.2.6b shall be made from each lot of 5 tons or fraction thereof.

 

 

5-2-6 AREMA Manual for Railway Engineering

 

2.2.8 RETESTS (1968)

 

Spikes represented by bend tests failing to meet the requirements prescribed in Article 2.2.6a and Article 2.2.6b may be annealed and resubmitted. If the spikes fail to meet the third test, they shall be rejected.

 

2.2.9 PERMISSIBLE VARIATIONS IN DIMENSIONS (1968)

 

The finished spikes shall conform to the dimensions specified by the purchaser, subject to the permissible variations specified in Table 2-1.

 

2.2.10 FINISH (1968)

 

All finished spiked shall be straight, with well formed heads, sharp points and be free from injurious defects and shall be finished in a workmanlike manner.

 

2.2.11 MARKING (1968)

 

A letter or brand indicating the manufacturer and also the letters “HC”, indicating high carbon, shall be

 

pressed on the head of each spike while it is being formed. When copper is specified, the letters “CU” shall be
added.

 

 

 

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Funny I have that as MAX percent carbon not min percent

American Railway Engineering Association's Specifications
Page 5-2-3: Specifications for high carbon steel track spikes 1968. Carbon not greater than 0.30%, nor greater than 0.20% copper.

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Max makes more sense to me because of the bend tests. But if you're going to call them high carbon, it seems you'd also have to specify a min. to distiguish them from the regular spikes. More googling is in order -- later.

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LC spikes are already defined.


Page 5-2-1. "A low carbon track spike will not contain greater than 0.12% carbon nor greater than 0.20% copper.

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Good point. But the "minimum" claim is repeated here, in Table 1 -- and it turns out there's a new standard for all spikes. They've eliminated the HC/LC distinction. It's about 4/5 of the way through the document.

http://www.arema.org/files/library/2007_Conference_Proceedings/Improvements_Track_Fasteners_Cope_With_Heavy_Axle_Loads_2007.pdf

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I used to have one of those funky Evergrip screw spikes. I didn't know what it was. Now I'm not sure where it is. :wacko:

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maybe I am just "nit picking" now too :)

Another term for "nit picking" is "being precise." :)

This has turned into a very good thread, everyone!

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I agree this has turned into a good thread. the point I was making is most wont expect 1020 to make a good blade, but thats close to what RR spikes are. People forget the differences between structural ratings (spikes, I-beam A-36) vs content ratings (10xx series, L-series). Content is close to what we expect, but the structural rating can be way out there, as to content.

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Of course many of us would be using spikes made to the old spec with a few new spec spikes thrown in...

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Can a rr spike portion be forged into Damascus to achieve a good hardness while retaining the spike head and drawing out a potion for the tang? Very new to smithing and would appreciate the feedback

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Your beter off making the funiture to forge rail spikes and then forge your custom spike into knives or bag axes.  Thus you can forge a nice pattern welded billet, spring stock or tool steel into a rail spike shaped blank.

 

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Can it be done?---Yes. Can someone new to smithing do it?---No!

I've also seen some nice San Mai  knives done using RR spike for the low C parts.

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On 7/27/2019 at 4:44 PM, Dedzone said:

Very new

Welcome to IFI... I always suggest reading this to get the best out of the forum. READ THIS FIRST   If you edit your profile to show your location we won't dunn ya for it when an answer requires knowing that.

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