First attempt forging a knife

[Hawk200]

Here is my first attempt at a forged blade.  The piece i used to start with was 6.5 inches of 1084 steel.  I drew it out to 11.5 inches and shaped it.  The grind isn't finished yet as I have to bevel it out and finish forming the grip on the tang. I will take care of that this coming weekend and heat treat it. I learned a LOT from the forging process as far as hammering is concerned.  Grinding is harder than I expected but i'm using a 1x30 belt grinder so it's taking a long time.  Any and all suggestions are welcome if you have any!

 

 

 

 

[EnglishDave]

Looks good, I have only made a couple of knives so far myself but one thing worth bearing in mind is that if you plan on drilling holes in the tang for pins to hold handle scales on it is a very good idea to drill them before heat treating the blade else it can easily become so hard you will be unable to drill it!

[Hawk200]

Good catch!  That was the plan as well but I failed to put that in the post. 

 

[Buzzkill]

Looks pretty darn good for your first try.  Just a small suggestion though.  If you're not going to put a guard on it then you may want to narrow the tang slightly where it meets the blade.  That provides a little more knuckle clearance and makes it less likely that your hand will slip forward on to the cutting edge in use. I'm not suggesting you narrow it much, maybe a quarter inch or so.  If you follow the line from the rear of the tang toward the blade it should give you a good result.  Keep the rounded shape you have though.  You don't want sharp inside corners as they are stress points for breaking.  I'm looking forward to seeing it finished.

[Hawk200]

Thanks, Buzzkill.  I really appreciate the suggestion and I will do that.  Seeing as it's my first attempt I probably won't stress myself out with making a guard on this.  

 

[Will W.]

3 hours ago, EnglishDave said:

Looks good, I have only made a couple of knives so far myself but one thing worth bearing in mind is that if you plan on drilling holes in the tang for pins to hold handle scales on it is a very good idea to drill them before heat treating the blade else it can easily become so hard you will be unable to drill it!

Why would you harden the tang? That would actually be detrimental unless you tempered it back to blue, and even then, its better to be softer than that.

[MastaStan]

Looking good, push on and up.

[Hawk200]

Thanks, Stan.  

 

Will, so it's better to not harden the tang?  I want to make sure I get this right so I appreciate your insight.

 

 

[Will W.]

Hawk

The main reason we harden the blade is to make the edge more wear resistant and last longer. We temper it to reduce the brittleness. The tang absolutely does not need to be hard. It does not have to hold an edge. And if you have a heavy use blade like a Bowie or a cleaver, its better for the tang (and the blade, to a degree) to have a little give. On top of that, a tang meant for scales has holes in it, so if it is hardened, a failure is more likely to happen there, if used heavily.

[Hawk200]

Ok, that makes perfect sense, Will.  I certainly understand the reasoning for the blade portion but I wasn't clear on the tang.  

 

I REALLY appreciate the feedback!

[Will W.]

Back to the topic on hand, however, your blade looks pretty good so far. Leagues better than my first attempt at a knife. Keep at it and keep us updated!

[EnglishDave]

1 hour ago, Will W. said:

Hawk

The main reason we harden the blade is to make the edge more wear resistant and last longer. We temper it to reduce the brittleness. The tang absolutely does not need to be hard. It does not have to hold an edge. And if you have a heavy use blade like a Bowie or a cleaver, its better for the tang (and the blade, to a degree) to have a little give. On top of that, a tang meant for scales has holes in it, so if it is hardened, a failure is more likely to happen there, if used heavily.

So do you achieve this by not heating the tang to critical temp or by not quenching it or a little of both?

[ThomasPowers]

Well in the early medieval period it was also sometimes done by forge welding a low carbon stub to the end of the high carbon blade---some wootz blades used this method as well in later periods in places like India.

So like a lot of Blacksmithing: There is only *ONE* correct way to do it and that is ANY WAY THAT WORKS!

One of the pluses in hand made blades is that you can do differential hardening and differential tempering and so get superior properties where commercial blades tend to be batch heat treated with a uniform heat treat.

[Jclonts82]

I have done it by heating the whole blade to the same temperature, (depending on the steel but usually around 1500 +/- 75deg F) then quench just the blade, or even just the cutting edge and about 1/2-1" towards the spine. I hold it there until the tang/spine starts to loose color, dull red then quench the whole thing. This is an effort to lessen/avoid a problem with changes in crystalline structure, below. 

 

Steve Sells authored a book, beginners guide to knife making, or something of the sorts and he goes into a lot of detail on it. I recommend purchasing it. I did, read it about 3 times now. You can find it on amazon. 

 

One argument FOR whole blade & tang quenching is to not have a rough 'transition' of steel crystalline structure. If the blade portion is converted to one form of steel, and the tang is not, there is going to be a zone/line where that transition occurs. It can be a weak spot and prone to failure. To help these cases, you quench the whole thing, then with a torch soften the tang from the back up to where your forward-most pin will go. I have done this as well, usually heat to a blue-gray color for most of the tang, and very gradually lessen the heat towards the blade in an effort to not soften  within 1" of the cutting edge. Where the tang meets blade I go dark brown with the heat, and straw on the blade itself. 

 

Hope this helps. Again, cannot recommend Steve's book enough.

[Latticino]

Another issue is depending on what type of steel you are using it is easy to get hardened layers within the steel even if no formal liquid quench is performed.  To be fully soft many steels need to be spheroidally annealed (which typically involves bringing the steel to the critical temperature, holding it at that temperature and then cooling it very slowly over a period of many hours).  This is not what a typical bladesmith does after forging is completed, so even though a tang is never formally quenched there is always a chance that it may have hardened somewhat (or have some lamellar pearlite hardening) from either being air cooled during normalization or during a  differential quench of only the blade or blade edge.  I agree completely with the other posters who recommend drawing a temper in the tang as well.

For mine I prefer to go this route:

1. Forge the blade.
2. Anneal by either heating to critical and leaving overnight in my gas forge with closed door, or programmable heat treat oven (or in a 5 gallon bucket filled with vermiculite or wood ash, not sand) to cool slowly
3. Grind profile and bevels, and drill pin holes ready for heat treatment
4. Normalize 3 times at successively cooler temperatures
5. Heat to critical and quench entire blade in appropriate quenchant (have also successfully edge quenched to create a temper line and have a softer spine on thicker blades)
6. Temper blade back to desired toughness (using either oven, torch, dragon's breath from forge, tempering tongs...)

[Will W.]

1 hour ago, EnglishDave said:

So do you achieve this by not heating the tang to critical temp or by not quenching it or a little of both?

In my case, both. I only heat and submerge the blade. The tang is both (relatively) cold and above the oil. In the case of an ax or a pick, I only quench a few inches from the edge. These processes have never lead me astray. 

 

[EnglishDave]

4 hours ago, Will W. said:

In my case, both. I only heat and submerge the blade. The tang is both (relatively) cold and above the oil. In the case of an ax or a pick, I only quench a few inches from the edge. These processes have never lead me astray. 

 

That sounds like a reasonable approach to me

[lanternnate]

Hmmm sounds like a lot of fuss that could be solved by just drilling the holes before heat treat  With a small knife it may not be really possible to get the blade entirely to desired heat without also getting the tang heated. Trying would also make me a bit worried about the difference in heat from tip to ricasso where I'd prefer that be as uniform as possible. If the tang is heated but not quenched, you still have a heat mass when you remove from the quench that could creep back into the blade and possibly temper it higher than you want. I get the benefits on larger longer blades or things like axes, but on small knives are the potential forces involved worth the potential undesirable side consequences? I would think modern steel uniformly heated, quenched, and tempered would provide sufficient toughness with least chance of something unwanted occurring. Is this incorrect thinking?

[Will W.]

38 minutes ago, lanternnate said:

Hmmm sounds like a lot of fuss that could be solved by just drilling the holes before heat treat  With a small knife it may not be really possible to get the blade entirely to desired heat without also getting the tang heated. Trying would also make me a bit worried about the difference in heat from tip to ricasso where I'd prefer that be as uniform as possible. If the tang is heated but not quenched, you still have a heat mass when you remove from the quench that could creep back into the blade and possibly temper it higher than you want. I get the benefits on larger longer blades or things like axes, but on small knives are the potential forces involved worth the potential undesirable side consequences? I would think modern steel uniformly heated, quenched, and tempered would provide sufficient toughness with least chance of something unwanted occurring. Is this incorrect thinking?

No it's not incorrect, there's no "this is the ONLY way to do things" anywhere in blacksmithing. 

When dealing with small knives, I find it best to quench the whole thing, but try not to get the tang past critical. Therefore, quenching does zilch to the tang. 

Regarding the tang being a heated mass, I always leave the blade in the quenchant until the tang is relatively cooled, and then immediately clamp the blade in between two heat sinks, so they soak up any additional heat. 

If the tang is brought to critical and quenched (like on a small knife), I agree tempering it back at least to blue is the best way to go. 

And yes, drill your holes before heat treat 

 

[C-1ToolSteel]

When I quench blades, I first quench the blade without the handle (or just the edge for an edge quench) and keep just the blade in the oil until the handle is well below critical, then quench the whole thing. The handle will not harden once it is below critical.

[Hawk200]

Thanks, everyone.  that's a lot more responses than I expected.  I will do the heat treat this weekend and post how it went.  

Another question I have is: should I heat the oil up prior to the quench?  I've read that some people don't and others say to do it.  I'm not exactly sure which is the best route to take here.

 

[Buzzkill]

The rule of thumb is warm the oil.  140 degrees F seems to be about where most people recommend.  The reason for warming the oil is its flow rate.  As you know warmer oil flows better than cold oil. When we quench that means the vapor pockets around the blade are displaced faster with warm oil than cold oil, which results in a more uniform and fast quench. Oils designed specifically for quenching may or may not need to be warmed.  The manufacturer recommendations should be followed for those.

[MastaStan]

Yes definitely heat your oil first. Read up on heat treating etc on here and you'll be fine. Look into your 1084 for advice on hardening and tempering.

[Hawk200]

Thanks, Buzzkill and MastaStan.

[EnglishDave]

21 hours ago, Hawk200 said:

Thanks, everyone.  that's a lot more responses than I expected.  I will do the heat treat this weekend and post how it went.  

Another question I have is: should I heat the oil up prior to the quench?  I've read that some people don't and others say to do it.  I'm not exactly sure which is the best route to take here.

 

No fancy oil heaters required for this of course, just heat up a hunk of steel and drop it in the tank prior to the quench (assuming of course there is some way to retrieve the hunk later )