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View Full Version : WIP: First Attempt at Forging a Knife



GlassEye
09-16-2013, 07:18 PM
I got the urge to try forging a knife last night, found a couple pieces of rebar in the yard and started research on what I would need to do to make it into a knife. This is my first attempt at forging anything and making any type of knife.

The knife is supposed to be a small utility knife, 2.5" blade, about 6" overall.

This is the forge I threw together from some housing bricks and a propane torch. Worked pretty well once it got heated up, ran it for three hours straight at full fire with no problems after some slight cracking sounds at startup.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/1991BC51-C68A-435A-9D00-EFABC7879697-6311-000009E22ABE7B84_zps17660f3e.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/1991BC51-C68A-435A-9D00-EFABC7879697-6311-000009E22ABE7B84_zps17660f3e.jpg.html)

Finished forge shaping. Blade close to desired thickness at spine, forged some slight thinning toward edge. I had trouble drawing out the heel like I wanted, but I have enough metal to work with to get close to my desired profile. Handle was tapered.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/6F7C9BC4-28EB-4600-8FE9-3DAC22613D7D-6311-000009E21E0E9C9A_zps358e729c.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/6F7C9BC4-28EB-4600-8FE9-3DAC22613D7D-6311-000009E21E0E9C9A_zps358e729c.jpg.html)
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/9AE7EF59-6B55-47A7-A1C6-7D1BBF6BBC5D-6311-000009E2C0183853_zps4d02f3d5.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/9AE7EF59-6B55-47A7-A1C6-7D1BBF6BBC5D-6311-000009E2C0183853_zps4d02f3d5.jpg.html)

Since I don't have proper hammers for this type of work, I one-handed a sledge hammer for the majority of the work accompanied by a small ball-peen hammer. For an anvil, I used the little flat anvil spot on top of my bench vice.

This is about 3.5 hours total, including building forge, to this point. I hope to finish this week. I will continue to update this thread as I work on this.

GlassEye
09-16-2013, 07:34 PM
Here is the forged blank with the original rough sketch. When overlaid it appears I should be able to make the sketch work.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/2CD91443-1B9D-470D-9BF3-083D64E904C1-6311-000009E520967F1F_zps58da4f0d.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/2CD91443-1B9D-470D-9BF3-083D64E904C1-6311-000009E520967F1F_zps58da4f0d.jpg.html)

Lefty
09-16-2013, 07:53 PM
Looks like fun! Next time, you should try to forge the tip shape, and you'll be able to get a tad more blade length out of it. I'm an expert forger, that's why I know this...cuz I'm an expert.... :happymug:

K-Fed
09-16-2013, 09:57 PM
Interesting. Does re-bar have enough carbon content to make it hardenable to a useable hardness?

Baby Huey
09-16-2013, 10:17 PM
I remember getting stabbed with rebar and it taking forever to heal. A co-worker stated that there was something in the chemical composition in the rebar that caused it.

CrisAnderson27
09-16-2013, 10:38 PM
Interesting. Does re-bar have enough carbon content to make it hardenable to a useable hardness?

Not usually. Rebar is a mish mash of metal...and not particularly well mixed. Some might have carbon, some not. Hell, some 6" pieces might have carbon in one end and not in the other. Even HC rail spikes are better to start with usually, because they have a consistent carbon level. It's low...but its there.


I remember getting stabbed with rebar and it taking forever to heal. A co-worker stated that there was something in the chemical composition in the rebar that caused it.

It was dirty lol.

GlassEye, if you're here in the US, PM me your address and I'll lop you off a 6" piece of 1/2" W1 to make your first knife from :).

:D

GlassEye
09-16-2013, 10:39 PM
Looks like fun! Next time, you should try to forge the tip shape, and you'll be able to get a tad more blade length out of it. I'm an expert forger, that's why I know this...cuz I'm an expert.... :happymug:
I did forge some tip shape at some point but it didn't really maintain that shape after working the spine and edge. As for next time, I'll see how sore my arms are after this one and go from there.

Interesting. Does re-bar have enough carbon content to make it hardenable to a useable hardness?
This guy seems to have had some success forging knives of rebar. (http://norsespirit.wordpress.com/2011/06/13/rebar-knives-how-and-why/)
What he is claiming is relatively low carbon, but the steel was free for me :juggler:
I am not expecting too much in terms of knife performance, but if I can get something I can use for opening boxes, letters, other little tasks I will be quite satisfied with the project.

GlassEye
09-16-2013, 10:45 PM
GlassEye, if you're here in the US, PM me your address and I'll lop you off a 6" piece of 1/2" W1 to make your first knife from :).

:D
Are saying the ugly lump of metal pictured above is not considered my first knife?:wink: Thanks for the offer, I'll decline for now but I'll let you know when it is time for the next one.

CrisAnderson27
09-16-2013, 10:51 PM
Interesting. Does re-bar have enough carbon content to make it hardenable to a useable hardness?


I remember getting stabbed with rebar and it taking forever to heal. A co-worker stated that there was something in the chemical composition in the rebar that caused it.


I did forge some tip shape at some point but it didn't really maintain that shape after working the spine and edge. As for next time, I'll see how sore my arms are after this one and go from there.

This guy seems to have had some success forging knives of rebar. (http://norsespirit.wordpress.com/2011/06/13/rebar-knives-how-and-why/)
What he is claiming is relatively low carbon, but the steel was free for me :juggler:
I am not expecting too much in terms of knife performance, but if I can get something I can use for opening boxes, letters, other little tasks I will be quite satisfied with the project.

Trust me...you can make knives from three different pieces of rebar, and have three completely different results in hardness, and my bet would be none of the three would even harden.

Now, I know nothing of this 'grade 60' he keeps mentioning on this page, but I don't think it's your typical rebar. The one thing about his site that makes me doubtful of his results though is his hardening procedure. Bright red in what light? What kind of water? The only real way to get .40% carbon steel to harden properly or reliably is cold brine (salt water) with a touch of dish soap...water is inconsistent (it CAN work...but not always!).

I'm serious about the W1, and I'd happily set you up with the correct process for hardening it as well. Its not difficult and the result you'll get is FAR superior :D.

CrisAnderson27
09-16-2013, 10:53 PM
Are saying the ugly lump of metal pictured above is not considered my first knife?:wink: Thanks for the offer, I'll decline for now but I'll let you know when it is time for the next one.

Sure thing! The offer stands...whenever you need it :).

If you'd like, I'd be glad to help you with the heat treat...even with that steel, freezing brine with some dawn in it will give you the best results. Also, do yourself a favor and skip the 'bright red'. Use a magnet...and when the steel will no longer stick to the magnet, heat it a tiny bit more, then quench.

GlassEye
09-16-2013, 11:29 PM
Sure thing! The offer stands...whenever you need it :).

If you'd like, I'd be glad to help you with the heat treat...even with that steel, freezing brine with some dawn in it will give you the best results. Also, do yourself a favor and skip the 'bright red'. Use a magnet...and when the steel will no longer stick to the magnet, heat it a tiny bit more, then quench.

Thanks for the advice. So, heat to non-magnetic and then some, quench in cold brine with some dish soap.

CrisAnderson27
09-17-2013, 12:02 AM
Thanks for the advice. So, heat to non-magnetic and then some, quench in cold brine with some dish soap.

No worries, glad to help :).

Yes, non-magnetic plus a tiny bit (basically ensure the entire blade won't stick...then look for the next tiny shade of color...should take a couple seconds or so). Quench in ice water that you've added some dawn to...as well as salt to until it won't dissolve anymore. IF there's carbon in it...that'll do the trick. Check for hardness with a file. Also...as he said, you shouldn't need to temper it.

WillC
09-17-2013, 02:37 AM
A tip for forging the tip in round bar. Forge a square sided point on the end, knock the corners off, forge to round. Then set your heel and choil and draw the taper into the tip. You will need to refine the tip shape as you go. Forging temperature in general, bright yellow, around 1150 degrees c. Try not to forge below a yellow heat unless you are surface finishing. Or it is needlessly hard work.
Blacksmith school most used phrase, "Get it hot":D
You should refine the grain after forging however. Can be done in your pre-heat treatment by normalizing. Heat to non-magnetic 3 times checking straightness and air cooling.

GlassEye
09-17-2013, 02:04 PM
A tip for forging the tip in round bar. Forge a square sided point on the end, knock the corners off, forge to round. Then set your heel and choil and draw the taper into the tip. You will need to refine the tip shape as you go. Forging temperature in general, bright yellow, around 1150 degrees c. Try not to forge below a yellow heat unless you are surface finishing. Or it is needlessly hard work.
Blacksmith school most used phrase, "Get it hot":D
You should refine the grain after forging however. Can be done in your pre-heat treatment by normalizing. Heat to non-magnetic 3 times checking straightness and air cooling.
Thanks for the tips.

GlassEye
09-17-2013, 08:07 PM
Todays update:
Did some grinding. Asymmetric right hand grind, single-bevel style right face with slightly convex(I was trying for flat) left face. I feel I should mention that I am doing all of the grinding on a 3400rpm bench grinder, as that is all I have to do the job. I will try to work on stones (and maybe files) only after the HT because this grinder would probably kill it pretty quickly.

http://i821.photobucket.com/albums/zz133/glasseye72/KKF/3662B6C9-27C8-4A3F-BB24-D803A1DD1405-357-000000BE07C5D319_zpsf75ae00f.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/3662B6C9-27C8-4A3F-BB24-D803A1DD1405-357-000000BE07C5D319_zpsf75ae00f.jpg.html)
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/2373CC88-58F1-48A6-A891-F0B090E393F2-357-000000BE128B037D_zps1336a3dc.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/2373CC88-58F1-48A6-A891-F0B090E393F2-357-000000BE128B037D_zps1336a3dc.jpg.html)

Finished grinding for today. I will probably clean it up some before attempting to normalize and HT this unknown steel from the yard.

http://i821.photobucket.com/albums/zz133/glasseye72/KKF/44AD960C-18E0-4373-A0AE-D3AC67DADF69-357-000000BE1A16B13F_zpsa1e850fd.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/44AD960C-18E0-4373-A0AE-D3AC67DADF69-357-000000BE1A16B13F_zpsa1e850fd.jpg.html)
The tip was left thicker for now.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/766B7A05-016C-4BDF-8C54-1D06D4046A16-357-000000BE246110A8_zps4dac2694.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/766B7A05-016C-4BDF-8C54-1D06D4046A16-357-000000BE246110A8_zps4dac2694.jpg.html)

Thanks for all of the advice everyone.

GlassEye
09-26-2013, 06:18 PM
A couple of updates.

I clamped a file to my stone holder and cut in the geometry. It is now flat on the left face and single-bevel style grind on the right face. I left the tip mostly unground still so it is not too thin during HT.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/76B7126C-4653-4F72-9703-A7F2A1F68C44-323-000000404684D645_zps5307b680.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/76B7126C-4653-4F72-9703-A7F2A1F68C44-323-000000404684D645_zps5307b680.jpg.html)
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/2247D8AE-A577-4538-81F8-6CEDD567A3B6-323-000000405067C021_zps0d3ac4e8.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/2247D8AE-A577-4538-81F8-6CEDD567A3B6-323-000000405067C021_zps0d3ac4e8.jpg.html)

Sanded today to 220 grit on the back and table, the file left some deep scratches which I am just going to leave there, it's character:biggrin:.
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/BC08B945-3F72-4414-BB9F-FB5404C698B5-323-0000004060D65573_zps5e29ff47.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/BC08B945-3F72-4414-BB9F-FB5404C698B5-323-0000004060D65573_zps5e29ff47.jpg.html)
http://i821.photobucket.com/albums/zz133/glasseye72/KKF/3DEC9A65-6C7C-4319-B34E-67C820B15C00-323-00000040590B3910_zps141ea39d.jpg (http://s821.photobucket.com/user/glasseye72/media/KKF/3DEC9A65-6C7C-4319-B34E-67C820B15C00-323-00000040590B3910_zps141ea39d.jpg.html)

Chuckles
09-26-2013, 08:13 PM
I'm impressed. Good work!

Lefty
09-26-2013, 10:52 PM
That looks really cool! Throw me in the impressed column.

theLawlCat
09-26-2013, 11:00 PM
Wow, that shined up nice. People sell things that look way worse for ridiculous amounts (see ugliest knife ever thread).

GlassEye
09-26-2013, 11:17 PM
Thanks for the kind words, everyone.

cord_steele
09-27-2013, 02:03 AM
Great work!