According to the older Phoenix post (Radium Foam IDL?? Vs. Latex International - #2 by phoenix) there are N and S lines of the Radium’s talalay.
Right now I’m inspecting local options and I have found 2inch blended Radium which should be N7540 according to the seller. 75 kg/m3 density, 4.0 kPa firmness and N to confuse people, probably.
Can some one help me to map N7540 to standard Sx nomenclature? The foam is definitely placed at the firmer side (medium-firm or S6-S9 range, I guess).
According to this post (Calculating density and other questions) 4.0 kPa = 28 ILD / 7.14. So it should be S7…
whoa :)… Ok. here’s my coffee cup, no research answer. “N” and “S” are referring to natural and synthetic (blend). I don’t know what the “…540” part of the N7 is, but N7 from Radium should be a target of 32 ILD (+/-2.5), and is likely somewheres around 80kg/m3. I think that roughly matches the kPa, but that is seriously above my paygrade (I’ve never heard it used by any latex manufacturer). I have never sourced the SBR latex from Radium so I’m not 100% sure that N7 = S7 but it would be evil if it didn’t… I’ve always assumed that the numerical designation from them was short for the kg/m3 but they said it wasn’t (I don’t believe them lol). ok. a 2” N7 is a pretty firm surface material, a medium deeper layer, and a soft base (not sure you needed that too, but what the heck). Hope that helps. (fyi, TG has an “N” designation too, but it does not match)
This is a good refresher for me…I had to slightly edit the ILDs. Honestly we don’t use them much when designing beds, it’s feel and previous experience, along with what’s around it.
Thanks. To be precise N7540 means type (N for blended) + density (75 for 75 kg/m3) + firmness (40 for 4.0 kPa).
The only question is how to map density / firmness to ILD. I believe ILD 28.5 (4*7.14) is the answer but 75 kg density seems bit too much.
Anyway, I have tried 3” N6S (20-25 ILD) as top + 2” N7540 as middle and I’m wondering what the middle layer really is for future reference…
Like I said, I’ve never seen or heard the “40” or “Kpa” designations used in their nomenclature. The “N” is their designation for natural, not blended/SBR. The N6 is divided into two tiers of firmness N6S (soft) and N6F (firm). Don’t ask me why (I think the target at certain densities becomes more difficult to control?). The target for N7, density wise, is 80 ish kg/m3. The slightly lower ild in talalay may be due to the higher elasticity although, once again, above my grade.
The N7 is two steps up the firmness range from N6S if that matters
I just wanted to jump in here for my own purposes, without sounding to forward. Why are we digging for this information? Are you building a mattress, taking latex classes in college, or general knowledge.
Maverick
I’m building a mattress using limited local options. Firm Latexco blended core (80/20 dunlop) on the bottom, Radium N6S on the top (natural talalay) and I’m trying to figure out middle layer because of the steep transition between top and bottom. Options are 2” blended Radium N7540 (local store) or I can buy something online.
Now it all makes sense. Best of luck on your project. Dont overthink it, just do what ends up being comfortable and done.
Where is this? Just curious as I’ve never seen the n designation used for an sbr latex (usually n means natural—at least in English). A 30 ild talalay (our n7 at least) should be a nice transition between the latexco (novaya now) and the N6S. Good luck!
It’s an European foam coding standard, I think. At least the last 4 digits encoding density and firmness (in kg and kilopascals). Using N for sbr/nr blend is probably Radium internal mess or seller typo.
" HR50160 is a high-resilience Richlux® High Resilience HR50038 foam with a density of about 50 kg/m3 and a firmness of about 160 N according to the ILD method and about 3.8 kPa according to the CLD method."
See here for more details: Functional foam mattress Osaka Air - ONSEN
Based on my research today, the confusion comes from the fact that Europe and the U.S. use completely different coding systems for latex and foam, even though they often use the same letters and numbers. In Europe, especially with Radium and many foam manufacturers, you’ll see codes like N6S or N7540. The digits usually relate to density (kg/m³) and firmness or CLD (similar to ILD) values (in N or kPa). This follows a European foam-classification style similar to PU foam labels like HR50160, where 50 is density and 160 is firmness. These codes don’t translate directly to ILD, and they are not tied to the U.S. Talalay softness scale.
In the U.S., Talalay latex is almost always classified by ILD or by simple softness grades like N1 through N5, where N stands for Natural and each grade corresponds to a soft, medium, or firm feel. So when someone sees something like N6 or N7, they assume it refers to the U.S. Talalay grade, when in reality the European Radium N-codes mean something entirely different. That mismatch is what’s causing the misunderstanding in the thread.
That’s my story and I am sticking to it.
Maverick