Sharpening old versus new

[on_the_edge]

I hope this doesn't sound like I've lost it, but for some time now, generally speaking, I have "sensed" that sharpening old production pocket knives seems easier than sharpening some of their contemporary production counterparts. For example, I have an old (80 years plus) Robeson that sharpens up very quickly and seems to stay sharp for a long time. I also have a GEC Toothpick that I cannot seem to get nearly as sharp no matter how hard I try. I realize that some of it is certainly due to blade geometry and stock thickness, but I am not convinced those are the only factors in play. Of course, I have no empirical or objective data to back any of this up; it's just my gut instinct.

So tell me--have I taken one too many sips out of the old flask or do you think I might be right?

 

[Tim616]

It could be heat treats may have gotten better (or I guess you could say better) at making the steels harder for some companies hence = harder steel = harder to sharpen.

Or you might be crazy....lol

 

[JAB]

^^Yup, it's been mentioned that most companies are running their steels a little harder than they used to. I definitely notice the difference between a modern CV from Case and a vintage version of the same model.

 

[kc custom]

I've Rc tested a fair amount of older knives that were 50Rc or even below, today we
call that hardness a spring. Not saying thats the rule but its sure out there esp.
on some of the older knives.
Ken.

 

[thatotherguy]

Yeah, companies will usually heat treat a blade harder now than they used to, so it'll be easier to sharpen older blades.

 

[Obsessed with Edges]

Knife blades heat-treated to mid-50s RC and beyond are a relatively modern phenomenon.

There was some discussion recently, related to older Case knives (maybe pre-1970, at least). And someone pointed out many of the knives of that generation & older weren't hardened to the same degree as their more recent counterparts. Those who have the tools to measure it, have documented older knives at hardnesses in the 40s on the RC scale. I recently purchased a 1965 Case Folding Hunter (6265 SAB) that seems to hint at that, somewhat. Very, very easy to sharpen up, and it felt almost buttery-soft on diamond hones. Took a fine, wicked-sharp edge, too. But, it also dulls proportionately easily.

Add to that, even with many 'simple' carbon steels these days, additional refinement has occurred. In particular, the addition of chromium and vanadium have improved corrosion resistance, wear resistance and durability, but have also made those steels somewhat more challenging to sharpen up, especially when compared to some genuinely 'old' knife steel. Steel makers are always finding ways to tweak their recipes, mostly with increased durability, toughness & wear resistance as the goal. That's got to make some difference in difficulty of sharpening, too. Not as big an obstacle now, as we have so many more tools available to us, to ease the process.

 

[Gevonovich]

Funny how I had your exact feeling just last night. I spent the night sharpening 3 very old knives I purchased. My method of sharpening is 600 and 1000 grit wet dry sandpaper and then a light stropping. I found that on the Keen Kutter, Kent, and old Case knives ( all carbon steel) that they sharpened up quite easily and the edge quickly became razor sharp. Can't yet speak to edge retention or durability. Also sharpened a newer Case and a Schrade ( both SS ) and they required more passes to get to the same ''gut" level of sharpness as the carbon knives I had just sharpened. The test was a pad of post its and a drop into the cut with an S curve cut through the paper. The carbon steel blades just seemed to glide through the cut much sooner. A little empirical evidence to add to Obsessed with Edges , kc and others explanations

 

[Obsessed with Edges]

I notice the difference in edge retention even during sharpening. The softer steels are much less forgiving, if I inadvertently mess up the angle or use too-heavy pressure. A very fine edge goes away in just a pass or two on the strop, if I goof up a little. This is how I noticed the difference in my older Case Folding Hunter, mentioned earlier. Got just a little too aggressive with it on the strop, and noticed a quick deterioration in the edge fineness. I've noticed that more modern steels, like the Sandvik 12C27Mod in my stainless Opinel and the D2 in my Queen folders, are much more tolerant of a few errant passes on the strop. I've even noticed this in the Tru-sharp steel in most of my modern Case blades, which many seem to regard as 'soft', by comparison to other modern steels. It's still much more durable than the older stuff; even the wire edges on these are somewhat difficult to remove. So, there's definitely a trade-off of ease of sharpening and the ability to take an extremely fine edge, in exchange for edge durability (or vice-versa), when comparing old vs. new.