DIY BLADE QUESTION

[brihacharan]

I would second essdee on the smaller blade size for your first attempt. There are a myriad of factors that come into play around bevel/grinding, blade proportions, cntr of gravity etc that you would only experience during a build. How these factors interplay and how small changes drastically affect the final blade form/function are much easier to understand in a smaller build.
Regarding the steel and its treatment. If you have acquired the metal from a local hardware store, it would most probably be construction grade 208 or 304 (most common)steels with very low carbon content to yield good results from heat treatment. If so, you can also try the case hardening process which works by adding carbon externally to only the outer layers of steel. Whatever the treatment approach, keep it as the final step after the cutting shaping, grinding is complete.
All the best for the build.! We all await the pics of the completed blade.!

I was looking forward to your advise. Can you tell me how does one add carbon externally,
Regards
Atul

Just check this link out....
How to add carbon to steel. - I Forge Iron
www.iforgeiron.com › Blacksmithing › Alchemy, Formulas, Fluxes, etc
Briha

[astronomy.domaine]

Hi Atul bhai,
Case hardening can be acheived in different ways. The most efficient and effective process is Nitriding or Cyniding. Where the metal is heated in a cynide bath which acts as a source of free nitrogen &carbon which diffuses about 1-2 mm through the metal surface. This process is dangerous as cynide is highly toxic and difficult to get for diy purposes.
An easier way Is flame carborizing where the carbon rich environment is provided by the fuel itself. Examples are hardwood charcoal or a fuel rich oxyacetelin flame. Both are easy to acquire and use. But the tradeoff is that the process takes considerably more time (think 5-6hrs) of heating and the carbon layer is much thinner. Though, you can also boost this by quenching the heated metal in an organic oil which would supplement the carbon diffusion process. The exact composition of fuels(there are a few additives like baking soda and common salt) and the process can be referred to on various diy sites and research papers on the net.

[astronomy.domaine]

And yes,, using a had grinder may be a bit risky for the first time. I use it myself and I am not a stikler for over the top safety measures. But a decent eye protection is a must here as there would be particles and metal dust flying around. Another thing, pls dont try to use the grinder with 1 hand and the metal piece in another if u are not experienced with the tool...As briha sir has pointed out, even if u are experienced, things can still go wrong and with irreversible consequences. I have learned it the hard way with a plethora of scars on my hands. . Securely clamp the blade and grip the grinder with both hands with easy access to the starter switch. A good idea would be to watch a bicycle grinder (as kshitij suggests) go about his job on couple of blades. It would help u in understanding the angles of hold and how to merge bevels between different parts.etc...thats it i guess! All the best!

[aadhaulya]

Thanks,

I think I am ready to go ahead with the project.

Regards

Atul

[kshitij]

@astro, thanks for the info buddy

@atul, best of luck. Keep us posted

[kshitij]

@astro, thanks for the info buddy

@atul, best of luck. Keep us posted

[aadhaulya]

Thanks kshitij, I am out of town and will start on the project by Monday.
I would be grateful if someone could give me a design of a big mean looking knife

Regards

Atul

[kshitij]

Atul,
You could use the profiles from here http://dcknives.blogspot.in/p/knife-profiles.html?m=1

Take a 1:1 print. That should give you life sized dimension which you can trace on your metal sheet. Trace it a few mm away from the actual edge so that you have some margin to fine finish the profile.

[brihacharan]

Atul,
You could use the profiles from here http://dcknives.blogspot.in/p/knife-profiles.html?m=1
Take a 1:1 print. That should give you life sized dimension which you can trace on your metal sheet. Trace it a few mm away from the actual edge so that you have some margin to fine finish the profile.

Excellent link for blade profiles...Kshitij
Atul - as Kshitij mentions - keeping a 2mm to 3mm outer margin is important, especially if you're going to cut the profile manually...
As this allows to take care of any slip ups while cutting - any excess can easily be ground off....
Good Luck!
Briha

[astronomy.domaine]

I had cobbled up this largish blade some time back. Its based on the Chinese butterfly sword. Blade length is 11.5 inches and the grip is 5.5inches. the lines are quite simple and can be a good for a first build. I have used automotive spring steel here and its thick (7.5mm)and heavy. needless to say that the blade has great chopping machete like functionality... have a look...

[brihacharan]

Bravo AD - what a blade
Specifically admire the profile & the finish on the blade
Way to go bro!!!!!
Briha

[aadhaulya]

I had cobbled up this largish blade some time back. Its based on the Chinese butterfly sword. Blade length is 11.5 inches and the grip is 5.5inches. the lines are quite simple and can be a good for a first build. I have used automotive spring steel here and its thick (7.5mm)and heavy. needless to say that the blade has great chopping machete like functionality... have a look...

I can't even see the shape of the blade. I just keep admiring the finish and polish of your blades.

[aadhaulya]

Guys, I have started on the project but still can't figure out the construction of the handle, hilt etc. I think I will go with a round handle made out of a steel tube and covered by a round contoured wooden piece made on the lathe by a carpenter, covering both ends with stainless steel plugs. Lets see how it turns out. Or what is your opinion if it will look ok or not.

Regards

Atul

[kshitij]

Hi Atul,
Why do you plan to use the steel tube in the handle scales? Is there any specific function or reason you have in mind?
The general practice is to cut the handle profile out of 6 or 8mm thick flat wood. Then glue and rivet it to the blade on either side and sand down the egdes.
If possible please share pics of where you have reached in the project and the experts here can guide/advice/suggest you through the project step wise.

[aadhaulya]

kshitij,

I thought that the steel tube would be easier to weld and the threaded ends could be closed using SS blind plugs. Besides I cannot think of a design of the handle, also I have metal working tools but no wood working tools.

Regards

Atul