Forged in Fire episode last night
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Forged in Fire episode last night
Did anyone watch the Forged in Fire episode "Wind and Fire Wheels" last night? If so, did it make you cringe.
(For me, it was when they were beating the knives against the bike frames.) And for those that understand metallurgy, why isn't a bike frame suitable for making knives?

#2
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I didn't see the episode but I am a knife maker. Most common bike frame steel doesn't have as much carbon in it as we would want for hardening. For example, Reynolds 531 is said to contain .35% carbon. Most knife steels will have .70% or more.
On edit, you could probably make a knife out of the axles and bearings if you wanted to as they would likely be higher carbon.
On edit, you could probably make a knife out of the axles and bearings if you wanted to as they would likely be higher carbon.
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I think everyone went after the bike chain. They had to use two pieces though, someone did use the bearings, someone else went after the gears.
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How much carbon did the high tensile steel bike frames have?
Why not just beat the carbon into the steel like the Japanese did?
Why not just beat the carbon into the steel like the Japanese did?
#6
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The Japanese method of miltiple forge welds actually reduces carbon content. It was done in part to "clean" and homogenize a steel bloom from a charcoal powered smelter. The steel production method used typically results in a lump of metal with a lot of impurities and different properties.
You can add carbon to steel with a coal or charcoal forge but this process takes a lot of time and I think they use gas forges on the show.
#7
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In the context of the show, if I had to use two parts I would go for the bearings and the stem bolt or chain and box weld them with a bunch of 1084 steel powder.
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I like the show, but I hated to see bikes which I could build, getting torn up. I also hated seeing knives pounded onto metal bike frames.
One guy used the drop-outs. I think they all used chain,. One guy tried axle bearings but didn't want to clean them (what? a splash of mineral spirits and wipe them clean with a rag!) None of them appeared to know what a spindle was or where bearing cups might be ... headset bearings, BB cups ... headset races .... and maybe the cranks. But .... these folks were knife-makers, not cyclists, and as far as I could see their wasn't even a crescent wrench or an allen wrench in the shop anyway.
i hope none of the frames were my size ...
.
One guy used the drop-outs. I think they all used chain,. One guy tried axle bearings but didn't want to clean them (what? a splash of mineral spirits and wipe them clean with a rag!) None of them appeared to know what a spindle was or where bearing cups might be ... headset bearings, BB cups ... headset races .... and maybe the cranks. But .... these folks were knife-makers, not cyclists, and as far as I could see their wasn't even a crescent wrench or an allen wrench in the shop anyway.
i hope none of the frames were my size ...

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(BTW, I did watch FIF last night, but not this episode. I saw a re-run i've never seen, where they had the guys choose from 6 different damascus styles to build. Very interesting, I learned some new stuff.)
Last edited by Brocephus; 07-18-18 at 01:55 PM.
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Just watching it right now on the DVR. Very hard to watch the angle grinder cut the lock snd the bike rack. I guess it’s a different view of the material.
#15
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Beating carbon into it would take longer and be less reliable.
The chain is the most obvious part, ball bearings and the races, lug nuts would work, so would axles.
Usually what they do is either test harden a piece, or "spark test" it. Grind it and look at the size, shape, color and brightness of the sparks it gives off.
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4130 is a common bike steel from back in the day. This commonly has between .28% and .32% carbon.
The Japanese method of miltiple forge welds actually reduces carbon content. It was done in part to "clean" and homogenize a steel bloom from a charcoal powered smelter. The steel production method used typically results in a lump of metal with a lot of impurities and different properties.
You can add carbon to steel with a coal or charcoal forge but this process takes a lot of time and I think they use gas forges on the show.
Most of the vintage bikes bouncing around would have been some type of carbon steel... for example 1020. However, as far as I can tell, that is a pretty plain steel, not even high carbon content.
Would grease be bad for the forging?
As mentioned above, cones, races, bottom bracket spindle, springs from brake calipers, etc... would all be able to donate a bit better steel.
Stainless spokes?
If one had X-Ray diffraction, one could likely be very precise with one's calculations.
I'll have to check out the show sometime.
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Quality bottom bracket spindles may be better as they'd have to be able to be hardened for the race.
Hmm... I have my stainless Campy BB spindle. I've reground it once, and it is pitted again. Perhaps it is time to give it a new life. My headset could also use some refreshing.
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I think it's great, and everyone should check it out. Part game show competition (though the competitors often work together for steel gathering and will say helpful things to each other, never down or hinder each other), part mass mayhem and murder, part horror ("Did he really just take that knife and slam the blade edge into that bike frame hard enough to dent it...10 times??? That poor knife!"), and part documentary.
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What is the point of it?
It's CYCLECIDE.
And you've lost 30-60 minutes of your life you could have spent watching the CIA etc telling NCIS they were in charge and NCIS solving the crime anyway.
It's CYCLECIDE.
And you've lost 30-60 minutes of your life you could have spent watching the CIA etc telling NCIS they were in charge and NCIS solving the crime anyway.
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I wanted to be a knife-maker. I bought some blades and made handles, took a welding class, did some metalwork with brass and copper , made some guards ... never had the opportunity to get to real forging, and I needed a real job, so ... I never really wanted to work for the CIA or NCIS. I never really wanted to shoot someone to make a sloppy plot work out between commercial breaks. So ... I watch the knife show.

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I would love a knife, letter opener, whatever made from a Campy chain. Blade from the chain, handle from the same chain, just weld the links together.
Cool factor > function
Cool factor > function
#22
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Chromoly, 531, etc, would have been the higher quality metals for vintage racing bikes.
Most of the vintage bikes bouncing around would have been some type of carbon steel... for example 1020. However, as far as I can tell, that is a pretty plain steel, not even high carbon content.
Would grease be bad for the forging?
As mentioned above, cones, races, bottom bracket spindle, springs from brake calipers, etc... would all be able to donate a bit better steel.
Stainless spokes?
If one had X-Ray diffraction, one could likely be very precise with one's calculations.y
I'll have to check out the show sometime.
Most of the vintage bikes bouncing around would have been some type of carbon steel... for example 1020. However, as far as I can tell, that is a pretty plain steel, not even high carbon content.
Would grease be bad for the forging?
As mentioned above, cones, races, bottom bracket spindle, springs from brake calipers, etc... would all be able to donate a bit better steel.
Stainless spokes?
If one had X-Ray diffraction, one could likely be very precise with one's calculations.y
I'll have to check out the show sometime.
Grease would probably not hurt the forging aging nor the welding as it would burn off very quickly. It might leave a residue that would inhibit a weld though.
Spokes could work. I read an account of a Japanese smith welding a single spoke into the edge of a mild steel knife shaped object to give it an edge that could be hardened in post war Japan when metal was scarce. Stainless is harder to forge weld than non-carbon but it can be done by a better smith than I am.
#25
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None of the bikes they had looked like anything better than a Walmart special.