Paramount Blades: 420 vs. 440

[tstop4me]

The higher end Paramount blades have runners fabricated from stainless steel.  In a curious marketing strategy, they offer the blades in both 420 (specifically 420HC) and 440 (specifically 440C) stainless steel, with the 440 costing substantially more than the 420.  If the 440 holds its edge substantially longer than the 420, then the extra initial cost may be worth it, if fewer sharpenings are needed over the service life of the blade.  Edge retention is not simply a function of the alloy, however; it also depends on the specific mechanical and thermal treatment, so you can't make any general statement of 420 v. 440.  I wrote to Paramount for edge retention comparison of their 420 v. 440; but the answer I got appears to have been written by a marketing guy, rather than an engineer, so I didn't get the info I was looking for.

Forum members:  Anyone skate on both 420 and 440 Paramount blades?  If so, how did their edge retention compare?  I'd be interested even if you're not comparing the same model blade.  Answers I'm looking for are along the line of:

"I first skated in Paramount Model __ in 420.  I typically needed to have them sharpened after __ hrs of skating.  I then switched to Paramount Model ___ in 440.  I typically needed to have them sharpened after __ hrs of skating."

[davincisop]

I've not been on 420, but my understanding was that bc 440 is a stronger steel it's better for adults? At least that's what my blade guy said.

That said, those things held a sharpening for MONTHS. That's the one thing I miss about those compared to my current MK Dance, the sharpening I could go for 3-4 months, skating 10 hours a week and walking around without hard guards.

[Query]

I may be wrong, but I think Jackson Ultima has also sold 420 and 440 steel alloy blades in the Matrix lines.

I don't know of anyone who has run the experiments you would like on ice skating blades on ice. I suspect the results would vary with the mineral content of the ice, as well as how good a job you do of drying the blade, how you store it, humidity, and the exact edge shape the sharpener produces. Maybe even on smog. (I know by experience that salt spray in the air near seashores affects stainless steel bolt rust on roof racks and truck caps.)  Also on how much stress you put on your blades, and what types of stress. In other words, different people might get different results on how important the difference is between 420 and 440.

I can't imagine trying experiments on high end expensive blades, unless you have a bunch of ones that are too worn out to be used.

To add to the complexity of your question, this source

  https://www.bladehq.com/cat--Steel-Types--332

says that there is more than one type of 420, and more than one type of 440. (That source is talking about knives, not ice skates, which are used under very different environmental conditions than ice skating blades - so what it says about how long the edge lasts should be taken with a grain of salt.) On top of that, hardening also affects blade edge longevity, so there are a lot of variables.

Some of the new rental skates at work have been greased, though maybe that doesn't affect rust on the parts that touch the ice, because it rubs off. The sides of the blade feel a little sticky, and aren't quite as shiny as they would probably be without the grease, but the grease seems to be lasting a lot longer than the oils I have used.

Didn't you mention you have played with grease on blades? If so, what were the results, or didn't you feel like running experiments that could create rust on your expensive blades?

Be a bit cautious with Paramount. I have seen a Paramount blade that came apart during a jump landing. The lady said she had broken a bunch of them, by doing imperfect split jumps, which presumably created extra sheer stress. The ones I have seen (this was some time ago) were held together with adhesive, whereas the similar looking Ultima Matrix blades are held together with adhesive AND two screws. The screws add a tiny bit of extra weight, but it isn't clear it is a sufficient amount to matter. Of course, Paramount blade shapes are different than Matrix blade shapes, so longevity and weight aren't the only factors, as I'm sure you know.

With your technical bent, I bet you take good enough care with your blades that you don't need to worry about rust. Are you only worrying about durability?

[tstop4me]

I may be wrong, but I think Jackson Ultima has also sold 420 and 440 steel alloy blades in the Matrix lines.

I don't know of anyone who has run the experiments you would like on ice skating blades on ice. I suspect the results would vary with the mineral content of the ice, as well as how good a job you do of drying the blade, how you store it, humidity, and the exact edge shape the sharpener produces. Maybe even on smog. (I know by experience that salt spray in the air near seashores affects stainless steel bolt rust on roof racks and truck caps.)  Also on how much stress you put on your blades, and what types of stress. In other words, different people might get different results on how important the difference is between 420 and 440.

I can't imagine trying experiments on high end expensive blades, unless you have a bunch of ones that are too worn out to be used.

To add to the complexity of your question, this source

  https://www.bladehq.com/cat--Steel-Types--332

says that there is more than one type of 420, and more than one type of 440. (That source is talking about knives, not ice skates, which are used under very different environmental conditions than ice skating blades - so what it says about how long the edge lasts should be taken with a grain of salt.) On top of that, hardening also affects blade edge longevity, so there are a lot of variables.

Some of the new rental skates at work have been greased, though maybe that doesn't affect rust on the parts that touch the ice, because it rubs off. The sides of the blade feel a little sticky, and aren't quite as shiny as they would probably be without the grease, but the grease seems to be lasting a lot longer than the oils I have used.

Didn't you mention you have played with grease on blades? If so, what were the results, or didn't you feel like running experiments that could create rust on your expensive blades?

Be a bit cautious with Paramount. I have seen a Paramount blade that came apart during a jump landing. The lady said she had broken a bunch of them, by doing imperfect split jumps, which presumably created extra sheer stress. The ones I have seen (this was some time ago) were held together with adhesive, whereas the similar looking Ultima Matrix blades are held together with adhesive AND two screws. The screws add a tiny bit of extra weight, but it isn't clear it is a sufficient amount to matter. Of course, Paramount blade shapes are different than Matrix blade shapes, so longevity and weight aren't the only factors, as I'm sure you know.

With your technical bent, I bet you take good enough care with your blades that you don't need to worry about rust. Are you only worrying about durability?

420 and 440 refer to a series of alloys.  In my first post, I stated that Paramount specifically uses 420HC and 440C.  Also, as I stated in my first post, my question is focussed on the difference in edge retention (--> time between sharpenings) between the two alloys, as produced by Paramount.  General comparisons of the alloys aren't illuminating because of differences in thermal and mechanical processing used by different manufacturers. 

Right now I'm considering only Paramount because [as discussed in a separate thread] my coach has recommended Wilson Gold Seal for improving my scratch spin.  However, I want a stainless steel blade instead of a carbon steel blade.  Of the available stainless steel blades nominally patterned after the Gold Seal, only Paramount uses the small 12" radius spin rocker of the Gold Seal, as far as I've been able to track down [otherwise my first choice would be the Eclipse Titanium Pinnacle].

Rust is not an issue for 400 series stainless steel in a typical indoor rink ice skating environment.  I don't use grease on my blades; you're probably thinking of someone else.

Jackson has used different grades of stainless steel for different models of blades [currently AUS8 for their higher-end blades and 420J for their lower-end blades].  What's peculiar about Paramount is that they offer their stainless-steel models in both 420HC and 440C, at different price points.  Since I pay $25 a pop for sharpening, a higher initial cost might be cheaper in the long run if the 440C requires significantly less frequent sharpening than the 420HC.  That's the cost/benefit analysis I'm interested in.

[Query]

Even if you are right that corrosion is irrelevant (which contradicts Davincisop's experience and my own experience with high end high carbon steel MK Dance vs stainless blades. [I currently use 440C Ultima Matrix blades.] I was extremely careful to dry my blades, stored them right, and sometimes oiled the high carbon blades. Cared for that way, I saw no rust. But the Matrix blades still held their edge 2 or 3 times longer. [Of course, both 420HC and 440C are probably more corrosion resistant than the non-stainless steels the MK Dance blades I used were made of, so maybe the corrosion difference isn't as great]), I still think there are too many variables to generalize edge longevity resulting from different alloys, from one person to the next. Maybe you jump higher or lower than some skaters, or apply more or less sheer force. Or your sharpener leaves a somewhat different edge shape than another sharpener, or sharpens more quickly, heating the blade more (notice the red-hot sparks), which may re-temper or re-harden the edge to a different extent.

Regardless, since no one here has provided the comparisons you want so far, maybe a very observant skate tech who deals with Paramount blades would have noticed the difference.  E.g., "Mr. Edge" sells Paramount blades, among others - and is viewed by many as one of the best skate techs in the world. Give him a call? Likewise, if you trust your own skate tech, ask.

[Peach]

My daughter is an intermediate level skater doing doubles. She ihas had her 440 paramounts for 2 years. We get them sharpened about every  4-6 weeks.. 10-12 hours a week of skating. Her skate tech says sharpening lastscabout 40 hours. I only get them sharpened by 1 person. I havent kept close track, but i do think these last longer between sharpenings than the 420s. Her foot is done growing so the investment into 440s is worth it. Also, her well resoected ciach inly allows her skaters to use paramount.