Farrier rasp teeth

[Joel OF]

Having watched a small variety of YouTube videos by amateurs & pros alike, I'm a little confused why no one grinds off the teeth from on farrier's rasps before forging them into knives etc.

As they're not forging at a welding temperature, surely the raised teeth are just getting flattened down, potentially forming cold shuts. I would have thought this is most likely on the narrow edges rather than the wide faces.

I assume they're not grinding off the teeth because they want the pretty patterns of the teeth folded down, but surely that's at the expense of a homongenous tool?

Or am I just overthinking it?...

[SmoothBore]

Yeah, I believe you are.

A Bladesmith doesn't use a Rasp because he can't get "new" material.

He obviously wants the finished blade to show it's "hand forged" origins.

[bigfootnampa]

I think you’ve got it.  The general obsession with stress risers and such is a bit out of proportion IMO.  Most knives and such made from these items are significantly overstrength for typical uses.  Allowing for quite a bit of artistic leeway in their design and execution.  

[John McPherson]

If you take the time to haunt museums and collections the way many of the professional smiths who make high end reproductions do, you will be struck by how Light and Thin daily use weapons were historically. Also, how roughly made many items were when you get up close.

Fit and finish on ricassos and tang transitions, hilts and guards tended to be especially sketchy, but the blades were always smooth. This holds true from the Roman gladius right up to the Dragoon saber.

All of which is 180 degrees out of sync with modern sensibilities. Because many of our blades are not daily users, they are status symbols, or outright fantasy. Much like the court swords of nobility in the past.

If you don't believe me, take a look at any bladesmith's website who carries a line of 'field grade' or plain hunters vs Gentlemen's knives, or kitchen vs zombie choppers.

[Joel OF]

36 minutes ago, John McPherson said:

If you take the time to haunt museums and collections the way many of the professional smiths who make high end reproductions do, you will be struck by how Light and Thin daily use weapons were historically.

 

1 hour ago, bigfootnampa said:

Most knives and such made from these items are significantly overstrength for typical uses. 

It sounds like what you're saying is that the folks who are making blades from farrier's rasps are leaving the blades quite thick, (certainly thicker in comparison to historical blades), so in a sense what they're doing is leaving the core of the blade solid and homogenous, (underneath the folded down teeth), with the outer top layers, (which are surplus to strentgth requirements) showing the texture of the folded down teeth. Yes?

I was imagining forging the whole thing down to about 3mm thick (1/8th). In that scenario wouldn't the teeth become so worked in that the blade becomes weak at the core?

I've never made a blade before and am only really asking the question because I thought making a herb chopper from one could be a nice gift for my uncle. I certainly wouldn't want the thing to snap whilst he's using it or he could end up with a sharp edge stuck his palm.
 

[John McPherson]

Not to get long-winded (too late), but yes to all of the above.

Yes, really working the teeth in, as opposed to grinding the tops off and leaving the dimples (see stolen image #1), weaken the blade.  I would suggest a progressive grind from the edge to the spine before forging out the edge. But it is just an herb chopper.  (Is there a market for Tactical or Zombie Apocalypse herb choppers?) You do not tend to rely on it and abuse it like a Bowie knife carried in the belt whilst hunting grizzly bears with a singe shot black powder rifle.

An edge quench in hot oil, leaving the body and tang soft is generally advised for blades made from high carbon steels like files and rasps, plus the hamon is considered aesthetic. Draw the temper in an oven starting at 350F for an hour, then 400F, 450F, etc., until a new file does not skate on the edge, so that it can be easily sharpened. If you still worry about it being tempered too hard, throw it on the concrete a few times. If it does not shatter: success!

[Will W.]

2 hours ago, John McPherson said:

Is there a market for Tactical or Zombie Apocalypse herb choppers?

Theres always someone out there who will buy anything. Theres a market for everything, its just how exclusive and niche the market is that is the variable. 

I think youre on to something, John. 

[JHCC]

I have a jar of undead oregano somewhere in my cupboard. 

[eseemann]

On 12/16/2017 at 5:12 AM, John McPherson said:

you will be struck by how Light and Thin daily use weapons were historically. Also, how roughly made many items were when you get up close.

Take a look at this site and watch the video on YouTube. they use a pile of bricks charcoal forge to make a great looking sword. 

http://www.pbs.org/wgbh/nova/ancient/secrets-viking-sword.html

NARRATOR: With the letters welded in place, Ric must now make something called the "fuller." The fuller is an indentation down the center of the blade. It reveals the ingenuity of Viking-age craftsmen.

RICHARD FURRER: You've got the start of the fuller, and that will get progressively deeper as we go. We're just going to bring that all the way up the blade.

The fuller allows longer blades, wider blades, yet the same weight as thicker, un-fullered pieces of steel, because it acts like an I-beam. An I-beam has structural members here and a horizontal. So, here, we have the fuller acting as the horizontal, and a little bit thicker material, and then going down to a cutting edge. So you have the minimal amount of material to give you the maximum amount of strength.

So, in this time period, the blades are getting longer and longer and longer, but the weight remains about the same. A completed sword weighs about two pounds, a little bit less, about like a baseball bat. Swords weigh about what a baseball bat weighs.

NARRATOR: The fuller made longer blades lighter.

 

All,

This is off topic but have you ever seen a smith file hot steel with a farrier's rasp? I saw this at the Athens Forge meeting and it watched this old smith file the 1600+ degree steel like he was grating parmesan cheese!

[JHCC]

3 hours ago, eseemann said:

have you ever seen a smith file hot steel with a farrier's rasp?

All the time: you'll see it referred to here as "hot filing". The round teeth on farriers' rasps are particularly well suited to this, but you can use just about any file with decent teeth. Wood rasps (with the long pointy teeth) aren't great, as they're designed to rip off wood fibers rather than to shear off wood or metal shavings.

3 hours ago, eseemann said:

Take a look at this site and watch the video on YouTube. they use a pile of bricks charcoal forge to make a great looking sword. 

http://www.pbs.org/wgbh/nova/ancient/secrets-viking-sword.html

@Ric Furrer is a valued member of this forum.

[Charles R. Stevens]

Yep, the 5# sword or axe of fantasy was not a thing, the 2# sword or axe was, even the battle axe was forged so it was thinner behind the cutting edge (not unlike the way logging days competitors grind their felling axes) 

[ThomasPowers]

It can be really hard to tell many early fighting axes from felling axes; but in general the lighter ones are fighting ones and the heavier are felling ones.

Heavy is slow and slow is dead on the battlefield!

Now of course there are some specialized versions like the Danish Greataxe that are definitely designed for fighting and also when the fighting comes home you grab the closest axe and use it. (I've had people guess the weight of medieval fighting swords at 20 pounds before; and remember Antonio Banderas not being able to use the swords in the 13th Warrior, so he grinds off the hardened steel edge to make it "light"?)

[eseemann]

5 hours ago, JHCC said:

@Ric Furrer is a valued member of this forum.

Now don't I feel like a dummy! I never put that together. I like Ric's posts and the "don't try this at home" profile pic.

[Joel OF]

Cheers for the input.

Pretty amazed these things actually work, I know nothing about bladesmithing and even less about cooking. Think hardening and tempering is actually needed for these? How blunt can they get on wood or plastic?

FWIW, I ground off the teeth on the cutting edge prior to forging.

[ThomasPowers]

Yes chopping sees a lot of abuse---ceramics, silica containing, etc.

 

[Mike Scan-D]

I love making these farriers file choppers. I'd never try to remove the file and rasp pattern, gives it character

[BIGGUNDOCTOR]

When I talked to the materials guy at the Nicholson file company he told me that their rasps, and wood files were of a lower grade of steel than their machinist files because wood and hooves are not as hard as steel. He would not give me the exact alloy designation they used, but did say that if the machinist files were heat treated like W-1 it would be OK.

Yes, technically the teeth will create stress risers in a hardened piece, but it will be up to you to determine if they will be detrimental in what you are making. Most use a rasp to have the design show, and not just for material.