Pena Fixed Blade

[Djmatts]

Hello all,

I’m having trouble figuring out what angle to sharpen my extremely dull Pena X Series Fixed blade.
Does anyone have experience sharping this specific blade?

 

[Alberta Ed]

Without knowing the geometry of the blade it's hard to say, but try the narrowest possible angle. 20 degrees is too obtuse; you can go down to around 10 degrees with most steels these days..

 

[TRfromMT]

D Djmatts - are you using a guided system? Wicked Edge or KME or similar? I'd suggest starting with the factory angle. Use a sharpie to see how you are contacting the bevel (which works just as well if you freehand). Just match whatever it is, regardless of the actual angle. Pena are pretty good quality so it should have a reasonably matched bevel that's uniform, and pretty straightforward to duplicate. I'd bet it's 20-22 degrees per side, or close to it, from the factory.

As to the post above, 10 degrees is just silly. Maybe a very thin, purpose designed chef knife or something. But you can get any quality steel to whittle hair at 20 degrees per side and have a reasonably durable edge. (I can post pictures if you like to show I know this to be true). 10 degrees per side is going to give you a very wide bevel that will look rediculous and edge that will fail quickly, not to mention it will take you weeks to profile it down to that angle.

 

[Obsessed with Edges]

Most important question is, what's the knife going to be used for?

For general non-abusive tasks considered typical for EDC knives, most any steel can handle an edge angle in the 25°-30° inclusive (12.5°-15° per side) range. 30° and below will also make for very good cutting in most any material. Very hard-use tasks like heavy chopping in tough materials might warrant a 20° per side (40° inclusive) edge.

As mentioned earlier, going down to 20° inclusive (10° per side) or lower is risky and could lead to more edge damage than you're willing to tolerate. Such edges are vulnerable to damage from even very light impact on anything hard (I've learned this the hard way). For very specific light-touch cutting, such as for light kitchen use or precision cutting of soft materials like leather, a narrower edge angle could be OK. But you'd still want to limit the use to only those tasks specifically.

Bottom line: When in doubt and lacking any other guidance, anything between 30°-40° inclusive (15°-20° per side) is a very safe place to start. You can fine-tune your edge to your preference down the road, once you get a feel for how well it cuts vs. how well it's holding up under use.

 

[Djmatts]

Thank you guys for the super info packed responses.

TRfromMT : For sharpener i'm using a basic Lansky guided sharpening system.
I think i'll start with that sharpie method, i'd rather put on the same angle that the knife originally came with if I can figure it out.

Obsessed with Edges : Knife is mostly used for daily tasks like opening envelopes and boxes, so looking for a balance of sharpness and long lasting edge. I will probably end up putting a 30-40 degrees inclusive edge on it if whatever factory angle is not durable enough.

 

[Obsessed with Edges]

Thank you guys for the super info packed responses.

TRfromMT : For sharpener i'm using a basic Lansky guided sharpening system.
I think i'll start with that sharpie method, i'd rather put on the same angle that the knife originally came with if I can figure it out.

Obsessed with Edges : Knife is mostly used for daily tasks like opening envelopes and boxes, so looking for a balance of sharpness and long lasting edge. I will probably end up putting a 30-40 degrees inclusive edge on it if whatever factory angle is not durable enough.

Boxes & envelopes is typical of the sort of tasks I use mine for. A 30° inclusive edge works very well for that - although one of my favorite box blades is more acute than that, probably flirting with 25° or slightly below on an already very thin blade (and very thin blades are best for cardboard, in general).

A great compromise is something like a 25°-30° inclusive edge with a 40° inclusive microbevel applied minimally in very few passes at the lightest possible touch. After my edge is set in the 25°-30° range, I do the microbevel on my Sharpmaker using the 40° inclusive setting, with maybe ~5 or fewer featherlight passes per side on the rods. I view this as just enough to clean up any weak remnants of burrs along the apex, while leaving a barely perceptible microbevel behind. This adds stability to the edge, which adds a noticeable consistency in cutting. Sometimes, a 25° inclusive or narrower edge can move around a bit, side-to-side in cutting, as this flirts with the limits of edge strength at typical hardness levels. Adding the micro to the edge makes it stronger at the apex.