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5160 Integral Sashimi knife


Gerbrand
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Hi Guys

It's been a long time since I've been here. In fact, it feels like forever since I've made something with a hammer.

I got an order from a friend to make an integral sashimi knife. We are both 3D artist by profession, so in this case, I got the design from him as a rough 3d model

 

0_3d.jpg

 

He asked for a dovetail design in the handle. At the moment I have no idea how to do this :)

 

 

I started with a round bar of 5160

 

1_5160roundbar.jpg

 

It has been a while since I've forged, so it went a bit slow. Also a round bar this thick is pretty tough to draw out

here is the thing after 1 hour of forging.

 

2_1hour_forging.jpg

 

Here its starts to look like it might be a knife one day. This is after two hours

 

3_2hour_forging.jpg

 

Three hours. Here I'm starting to work on the integral part. I don't have the right tools to forge a proper integral so I'm just hammering it into the shape it should look like.

 

4_3Hour_forging.jpg

5_3Hour_forgingB.jpg

 

This is me starting to hammer the profile out

 

6_me_trying_to_use_a_hammer.jpg

 

This is the final forge. Took 4 hours to get it to this point. I'm not confident to hammer any further, so I left it thick enough to make sure I can grind all my mistakes out

 

7_4hours_forging.jpg

 

Here is a quick shape grind

 

8_Cleanup_grind.jpg

 

This is the shape before I start thinking about the heat treat

 

9_Shapeb4HTA.jpg

10_Shapeb4HTB.jpg

 

I need some advice here:

I would like to put a hamon on this knife but I don't want it to curve up, so I thought I would scrape the spine clean. Do I add the edge bevel now or after the heat treat. The bevel will only be on the one side of the knife, but I'm worried that the knife might warp due to the non symmetrical bevel if I grind it in before I heat treat. I would also appreciate some advice on heat treating 5160 . Up to now I've been using 1050 and 1070 with water quenches. I'm going to try an oil quench for this knife but I'm not sure if I should interrupt the quench or not.

Any comments would be most welcome

Thanks for looking

Gerbrand Nel

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Gerbrand, first off, great job forging. It has nice lines and is well executed. PLEASE do an oil quench on this knife - 5160 will not respond well to water, as it was designed as an oil quenching steel. Oil will make a blade bend down, not back like a water quench will, and the bend is much less.

 

In a blade this length it isn't much of a concern anyway, but yes, I would not clay the spine. I always remove the clay from the spine because it does help with the curvature and I like the pattern it produces. I think you'll be a bit disappointed with the hamon you get from 5160. It is through hardening so it's tough to do, but it is possible to get a faint simple hamon. My advice is to make a simple clay application - just a straight line, as you won't get much activity in the hamon anyway.

 

I have had good luck quenching blades with a chisel grind. You can grind the bevel prior to HT, but leave some meat on the edge (1/16") and finish the edge after HT. The clay helps with this also. If the blade does curve remember that you have a short window to straighten it after quenching before the blade becomes brittle. Make sure the blade is still at least 250 F when you do this, if it's cooler it WILL break.

 

Good luck!

 

-Todd

www.toddblades.com

 

"Geometry says how sharp, steel says how long." - Roman Landes, Ashokan 2009

 

"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf."

 

- George Orwell

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Thanks for the response and encouraging words Todd.

Should I normalize like I do with 1070?

My thoughts were to heat to critical and let it cool inside the furnace 3 times before I do the ht. Does this sound about right?

Any idea what the critical temp is for 5160, or should I just use a magnet as always?

Thanks again

Gerbrand

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Yes, do normalize. The critical temperature for 5160 is around 1600 degrees F, somewhat hotter than non-magnetic. You don't need to leave in the furnace to cool, but do keep it somewhere warm. 5160 in thin sections tends to air-harden a bit.

 

Nice forging, by the way! B)

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IMO normalizing is always a good idea. I even do it on a pure stock removal project because who knows what that steel has been through before you get it, and grinding itself can cause stresses that normalizing will relieve.

 

If like Alan said you want a slower cool down but don't want to tie up your forge you can put the blade in wood ash or wrap it in insulwool or whatever mineral fiber you use.

 

Please post the finished blade - I'm looking forward to seeing it. :)

 

-Todd

www.toddblades.com

 

"Geometry says how sharp, steel says how long." - Roman Landes, Ashokan 2009

 

"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf."

 

- George Orwell

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If he'd wanted a hamon, W-1 drill rod would have been a better option, 5160 tho will make a great knife.

 

For the handle, it's fairly simple, you'd just dovetail two contrasting pieces of wood together, as though you were making a box or drawer but with the pieces lying flat. Glue them up together, then I'd drill them out for the tang.

 

I'd think an octagonal handle would be a lot more comfy in the hand, I dunno if you plan to leave it square like the image or not.

 

I kinda wanna try the dovetail idea now, as I've got just the tools for it =P

Beau Erwin

www.ErwinKnives.com

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Thanks guys

I'll do the bevel next and normalize after that.

I suppose I need to go buy a dovetail jig as I only have a router. I've never done any dovetail joints before, so I'm not sure how they work. I tried routing it by measuring the distance between cuts, but without being 100% accurate, the joints looked horrible, and didn't fit.

I saw a video on youtube where someone made a dovetail corner joint but I wasn't sure if the same technique would work for a straight joint.

The interesting part is that my friend wants the two pieces of the handle to be similar wood and even have the grain go the same direction. You should almost not notice the two pieces at all. I suppose I can appreciate the subtle approach, but its allot of effort for something that might become invisible after the knife has been used much.

I'll post some more pics later, but I start working again tomorrow, so I'm not sure when I'll have time to finish the knife.

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If you know the spacing you need, maybe you could dimension a long enough piece of hardwood or plastic that's the right thickness. Then cut it up into spacers that you stack against your router guide. That might move the cuts across your handle material with good accuracy, if you start with accurate spacers and watch for sawdust buildup.

 

That's not really a typical woodworking joint and it may be pure chance that you can find a commercial jig that'll do what you want, particularly with the thickness of typical handle stock. If your buddy wants subtle, maybe scribe the pattern into a solid block then soften it with a good hand rubbed finish. I'd retalk to him about expectations just to feel out how close to the drawings he's expecting the knife to look, particularly the hamon.

 

I appreciate the pictures and you do very nice metal work. Best of luck with that tricky handle, Craig

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Great work so far. I love integral itchen knives and this one is looking very good.

 

Id go for the octaginal handle, will be much nice to use.

 

Jamie

 

PS Where some glasses over your eyes dude. Forge scale to the face is never good but its really really bad if sticks to your eyeball. I dont mean to moan but I had an ember land in the corner of my eye and it hurt to blink for days.

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I've got an incrajig on my router table which is perfect for that kind of thing.

I was thinking even using the same wood, but then having a small strip of a contrasting wood running along the joint line would be neat. Say a handle in walnut, with a bloodwood dovetail line.

 

It'd be pretty spiffy, but take a little time to do.

I really need to watch the video that came with my setup and see what more it can do.

Beau Erwin

www.ErwinKnives.com

Custom knives

Bcarta Composites

Stabilized Woods

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I've got an incrajig on my router table which is perfect for that kind of thing.

I was thinking even using the same wood, but then having a small strip of a contrasting wood running along the joint line would be neat. Say a handle in walnut, with a bloodwood dovetail line.

 

It'd be pretty spiffy, but take a little time to do.

I really need to watch the video that came with my setup and see what more it can do.

 

The incra jig my brother has on his shop table saw will do all kinds of amazing joinery. it's really a neat setup

President - Georgia Knifemakers Guild

ABS Journeyman Smith

 

"Wisdom and experience are built of bricks made from the mud of failure." - Mike Blue

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Yeah it is, I used it to do the joinery for a storage/display case for a carving knife and fork set Brion Tomberlin made for a customer.

The finger joints turned out great. I'd used an older model over and my grandpa's and this newer one is great.

Beau Erwin

www.ErwinKnives.com

Custom knives

Bcarta Composites

Stabilized Woods

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  • 3 months later...

Hi everyone

I've been busy with other work since I last posted on here, but finally got a chance to tinker a bit over the Easter weekend.

I managed to do my three normalizing cycles overt the last few months.

After the first cycle I was surprised to find the blade had warped pretty badly.

I heated the blade to a dull red and corrected the warp by bending it in a vice and hammering it a bit with an old wooden hammer.

I didn't have any more warping after the second and third normalizing cycle so I moved onto the claying

I clayed the blade with "gungum" this time around. Its the first time I've used the stuff, an I must say, It's allot easier than mixing it yourself.

 

clay.jpg

 

My first attempt at hardening was a bit of a failure. The blade didn't harden at all.

After some reading and research I concluded that I didn't go high enough on the temperature and didn't hold it there for long enough. I think I had it at 815*C for about 60 seconds.

I decided to clay it again and this time went for 860*C and soaked it for 4 minutes. I quenched in a mixture of diesel, motor oil and automatic transmission fluid.

Unfortunately the same warp I had in the first normalizing cycle came back.

 

ht_warped1.jpg

 

ht_warped2.jpg

 

ht_warped2.jpg

 

ht_warped3.jpg

 

warp_edge.jpg

 

warp_spine.jpg

 

Could anyone tell me what I could have done wrong, and what to do from here. I don't want to trash this blade, as I'm pretty happy with the shape at the moment.

I would really like to do a differential harden on this piece, but I'm worried that the chisel grind is causing the blade to warp to one side when I heat treat

Any comments would be greatly appreciated

Thanks

Gerbrand

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If you're using 5160 skip on the clay and just do an edge quench.

5160 is quite deep hardening and will usually harden even with clay.

If you're wanting differential do a horizontal quench and set up a block in your tank that limits how far down the blade can go to get however much hardened that you want.

 

Claying it up is just extra effort for something that doesn't work well with it.

 

Looking like a great blade though!

Beau Erwin

www.ErwinKnives.com

Custom knives

Bcarta Composites

Stabilized Woods

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A chisel grind will cause it to warp. What you can do is try to prebend it in the opposite direction.

I've got some yanagiba/sashimi knives that I've done ni-mai/two layer and would chisel grind them post heat treat about 1/3 of the way up the blade.

I used 1080 and mild and when heating the suckers up they warp quite badly because of the differing steels. But being mild/1080 I just beat them back straight after tempering.

 

On yours being an uneven grind from side to side, it's likely part of the reason. One way around it would be taking the blade to thickness and hardening and then going back afterwards and grinding in the bevel.

 

The edge quench I mentioned above might held some as a lot less of the blade is hardening where in this one it's likely the whole thing hardening even with the clay. Also if it's just the edge hard then you might have better luck trying to straighten post temper as the upper portion would be softer.

 

I'd edge quench and hold it until there was no color left in the spine of the blade at all.

Edited by EdgarFigaro

Beau Erwin

www.ErwinKnives.com

Custom knives

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not much to add to what Edgar said ;)

 

for this type of steel, i'd through harden it (which is what it does best )

 

check this out...for straightening a hardened blade

http://www.bladeforums.com/forums/showthread.php/838681-Straighten-During-The-Temper

 

 

 

 

 

G

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  • 2 weeks later...
  • 2 months later...

Ok got a chance to work again today.. It's been so long I forgot where to turn my grinder on ;) I guess I shouldn't complain if my career is doing well enough to keep me out of trouble. Did a clean-up rough grind after the warping was fixed and did some rough shaping around the tang. this is about 2 more hours of work after the warp was fixed. Hopefully I can get some more time this week to start on the handle.

 

DSC_0178.jpg

DSC_0180.jpg

Thanks for looking!

G

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