"Rules" for swedges

[CUTS LIKE A KRIS]

I was just wondering if there are any written or unwritten rules for adding swedging to a knife. Last night I noticed more of my Slipjoints have cut swedges if a long pull and drawn swedges if there is a nail nick. Was wondering if this is just from my small sample size or if there is some logic behind it. Likewise, are there any rules for fixed blade swedges? How do you decide what type to use, how far back towards the handle you go, how deep into the blade, sharpened or not..... When would you NOT use a type, or any swedge at all?

Really any insight would be appreciated.

Here was my last attempt, I added it for a bit more flair and to reduce point thickness as the owner had me design it for hunting purposes. (I'm not much of either a knifemaker or photographer at this stage, sorry I don't have better examples)

 

[Cactus Kid]

Hey Cuts,

I will be interested in seeing where this thread goes, mainly because I don't think there are any rules to follow on swedges. I make fixed blades and when I do a swedge I almost always sweep it back instead of there being a vertical plunge line at the end of the swedge. I just think it looks better and smoother with the swept back look, much like yours looks in the pictures (good job the way)!

 

[Nathan the Machinist]

Functionally, I like a swedge on small folders because they help them cut smoother in curved cuts. Almost like a wiper flat. For example, deburring a hole like the bore of a cut PVC pipe goes smoother with a swedge on the back of the blade. I noticed this effect years ago and consider a swedge almost mandatory on a small EDC folder for me because it makes a difference to me in the shop.

On a fixed blade, particularly a big one, a swedge can act like a fuller in that your blade design can incorporate thicker stock for a particular weight. In that way it increases the area moment of inertia. And, in that way, by allowing some extra meat directly behind the point it makes a stronger blade - for a given weight. Or, looked at another way, it can remove a lot of tip weight from an otherwise big stout blade.

From a balance point of view, the intersection of a fuller and the primary grind creates distal taper without creating a thin weak belly and point.

A swedge makes good sense on a tactical fighter where you want high tip strength, reduced tip weight and less resistance to penetration.

A swedge makes less sense on a skinner or a kitchen knife where you want a narrow primary grind angle and full height grind.

They look cool.

They can be sharpened.

They're hard to grind because there isn't enough area in the grind for you to feel the grind. Having inspected the work of many big prominent makers, I'm going to say that everybody have trouble with them, particularly near the tip.

I rough them in with a fixture of sorts (a hanging parallelogram) but I finish them by eye. Literally by eye, you can't feel it. After it's roughed in, either by fixture or mill, I sight down a platen and look at the gap with my eye. And then, with my eye and my ear, I get the swedge aligned with the belt and finish grind it, without being able to feel it.

Nothing worse that a faceted lumpy swedge on an otherwise perfect finished blade. I've thrown away more blades for this than any other flaw.

 

[AVigil]

Swedge or not to swedge.

I like em

But they can be nerve racking if you do not have a plan that works.
.
I use the bubble jig and do swedges now with no fear.