F/S Broken tip, project

[digi-shots]

Ouch! Looks like someone wanted a throwing knife!

 

I bought this one a few years ago and put it in the "project pile". The price was right and I couldn't pass on it.

 

I had it out today, as I was measuring and comparing blade lengths, and thought I'd share some before and after pics.

 

I don't usually look for "projects" but this one needed some special attention and looked like it deserved it. The guard is stamped ^B2.

 

Thanks for looking!

[sgtdorango]

Wow great job!!....mike

[jw517]

What did you do? Grind it? Weld it?

[digi-shots]

Started with a grinding wheel... (not really my favorite) and didn't feel like I had any control. Did 99% of it on a table mounted belt sander - it's softer and has a little bit of give - it was a lot easier to keep the blade level with the belt and still be able to flip it over and over - keeping the center line as straight as possible, while beveling the edges.

 

I used the profile of another F/S knife and made a cardboard template for the tip - outlined the template with a black marker directly onto the broken tip - and started cutting away the area outside of the black markings.

 

It was a bit difficult with this profile of blade - it has 4 different sides or planes. In order to keep them even, I had to flip the tip over and over.. and then switch sides so that all four were evenly ground and the bevel matched the rest of the double edged blade. The trick was keeping the center line "centered" down the whole length of the blade.

 

It was a fun project and took maybe 2 or 3 hours. I'm sure whatever temper was on the blade has been lost due to the heat generated by the belt sander.

[doyler]

That looks great.

 

Well done.

[268th C.A.]

looks better than it did for sure....

[Blacksmith]

So, you did pure stock removal to recreate the original tip profile? When I first looked at it, I thought you built it back up with weld, and reshaped it (and thought "holy carp!"). Either way, really artful job. Well done.

 

Since it'll likely never be a working tool, I wouldn't worry about hardness / temper - it looks great. For fun though, in terms of the temper, I doubt a low-speed sander got it to temper temperature. To be conservative, if we use the tool steel with the lowest hardening temperature (O-1) as reference, you would need to achieve about 500*F. I have no clue what exact steel / process F-S used on their knives, but you would generally hardened them first (really hot / well over 1000*F then quench), then temper them at lower temperature to 'relax' them a bit and make them less brittle. You generally want a hard edge, with a relatively softer 'spine'. That way, it'll both hold an edge, and have ductility ("flex").

 

With as good of work as you did here, you should buy more project knives.

[digi-shots]

Thanks for all the compliments! This was my first and only attempt at reshaping a knife blade.

 

Blacksmith, thanks for the info on hardening... I knew there was a line between "too brittle" and "too soft" but had no idea of what temperatures were needed - and didn't know if I was messing it up or not. I wasn't planning on using it but did want it to look good. Someone probably tried throwing this one and the tip snapped.

 

I know the first issue of OSS blades from LF&C were rejected and did not meet hardness specs as they were too soft. After the initial shipment, many of the early knives were tested and some still failed. They were re-hardened and tested again. The ones that passed will have at least one punch mark on the blade (Rockwell hardness test). If they failed, they were re-hardened and tested again and will show an additional punch mark. The OSS stiletto that I have has a couple of punch marks - one on one side and two on the other about 5/16" apart.

[digi-shots]

LOL... I had to edit my previous post TWICE !!! For some reason the auto correct doesn't like a particular word - punch-P-R-I-C-K was changed twice to punch-nice guy

[Blacksmith]

You are welcome my friend. Far from messing it up, you did excellent work. Hard to believe that is your first attempt. Superb.

 

Thanks for all the compliments! This was my first and only attempt at reshaping a knife blade.

 

Blacksmith, thanks for the info on hardening... I knew there was a line between "too brittle" and "too soft" but had no idea of what temperatures were needed - and didn't know if I was messing it up or not. I wasn't planning on using it but did want it to look good. Someone probably tried throwing this one and the tip snapped.

 

I know the first issue of OSS blades from LF&C were rejected and did not meet hardness specs as they were too soft. After the initial shipment, many of the early knives were tested and some still failed. They were re-hardened and tested again. The ones that passed will have at least one punch mark on the blade (Rockwell hardness test). If they failed, they were re-hardened and tested again and will show an additional punch mark. The OSS stiletto that I have has a couple of punch marks - one on one side and two on the other about 5/16" apart.

[dskjl]

That looks simply amazing, great work!