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Sponge hardness table
http://ooakforum.com/viewtopic.php?f=9&t=1808
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Author:  iskandar taib [ 22 Jan 2014, 06:40 ]
Post subject:  Re: Sponge hardness table

No, I meant your Durometer readings. Sriver measures at - what did I say? 54, most of the 729 offerings don't measure that hard. The old 729 Super FX isn't on the scale (probably hasn't been measured yet).

Iskandar

Author:  haggisv [ 22 Jan 2014, 07:29 ]
Post subject:  Re: Sponge hardness table

Yes you're right. I must update the table, as I've got a lot of values to add, just haven't has time to get around to it. :oops:

Author:  iskandar taib [ 27 Jan 2014, 17:39 ]
Post subject:  Re: Sponge hardness table

Very interesting. Just got me a sheet of 729FX Super. Well, it's NOT the old 729 - I have one of the old sheets (the topsheet is starting to come loose from the sponge after all these years). The indentification strip says only "729", not "729FX", and there's no "Super" on the other side. This topsheet still exists - it's offered with the different soft "Cross" sponge in the "batwings" packaging as a "training rubber":

Image

(That's got to be the biggest "lot" sale I've ever seen on aliexpress.com. Not particularly cheap, either - I've seen this sheet go for around $4.50. So Liang Jialiang sells rubber sheets on aliexpress. Interesting. )

So I wonder - CAN you get the original 729 topsheet with the original hard blue sponge?

Iskandar

Author:  haggisv [ 02 Mar 2014, 15:16 ]
Post subject:  Re: Sponge hardness table

The Sponge Hardness Table has finally been updated, with now over 400 entries!
Although it's been a while since it was updated, I've been collecting values all this time, and writing them down, I just didn't get around to actually updating the table.
A lot of the latest rubbers have been added, so hopefully you'll find the ones you looking for.

A big THANK YOU to those people that have been giving me offcuts of their rubbers, so that I could measure them and add them to the table! :clap:

Author:  Big_Fat_Loop [ 28 Jun 2017, 09:11 ]
Post subject:  Re: Sponge hardness table

Are there multiple hardness standards used by manufacturers? It seems that, for example, a chinese rubber advertised as a 40-degree may actually be "harder" than a european rubber advertised as a 47 degree.

Author:  haggisv [ 28 Jun 2017, 09:44 ]
Post subject:  Re: Sponge hardness table

Big_Fat_Loop wrote:
Are there multiple hardness standards used by manufacturers? It seems that, for example, a chinese rubber advertised as a 40-degree may actually be "harder" than a european rubber advertised as a 47 degree.

Yes they do use multiple standards, which is the main reason for this project.

Author:  Big_Fat_Loop [ 28 Jun 2017, 10:22 ]
Post subject:  Re: Sponge hardness table

For the newer rubbers not listed perhaps there is a way to convert from one standard to another ... ideally it would be a linear conversion factor so one could just add or subtract degrees to compare more accurately ... but I suspect the manufacturers won't make it easy. Thanks for the great job.

haggisv wrote:
Big_Fat_Loop wrote:
Are there multiple hardness standards used by manufacturers? It seems that, for example, a chinese rubber advertised as a 40-degree may actually be "harder" than a european rubber advertised as a 47 degree.

Yes they do use multiple standards, which is the main reason for this project.

Author:  haggisv [ 28 Jun 2017, 11:42 ]
Post subject:  Re: Sponge hardness table

Yes you're right, not all the scales are linear. I did post one conversion chart here somewhere, which gave comparisons between 2 standards... I'll have to see if I can find it.

Edit: Here it is: viewtopic.php?f=44&t=23663

Author:  Big_Fat_Loop [ 28 Jun 2017, 12:09 ]
Post subject:  Re: Sponge hardness table

Got it, thanks. There is a conversion pattern between the 2 standards but unless new sponges are outside these ranges (<34 or >41 on DHS scale) hopefully we can still use the table as is.

haggisv wrote:
Yes you're right, not all the scales are linear. I did post one conversion chart here somewhere, which gave comparisons between 2 standards... I'll have to see if I can find it.

Edit: Here it is: viewtopic.php?f=44&t=23663

Author:  yoass [ 28 Jun 2017, 15:22 ]
Post subject:  Re: Sponge hardness table

Somebody posted a conversion table between the two hardness scales. Let me seeā€¦ yes, viewtopic.php?f=44&t=23663 has it.

Author:  igorponger [ 26 Dec 2017, 05:48 ]
Post subject:  Re: Sponge hardness table

Hi, Haggisv

I strongly suspect you do operate a durometer version with Shore A scale, not Shore C. The two devices are easy to confuse by their outlook.
The probe C looks the same as probe A , the probe tip shaped as truncated cone. But the C inner spring is much more power and hence the C durometer must indicate 15-17 on the Sponge materials.
You have mostly got the indication of 40-50 with your given durometer which is just the readings the A durometer should indicate.
It is clear, your present device in use is SHORE A, not C.

NOTE: as far as I know, all the table tennis manufacturers are using either A shore scale (truncated cone probe) or C Ascer scale (semi-spherical probe) for testing sponges.

Ever Yours.
Image

Image

Author:  haggisv [ 26 Dec 2017, 10:28 ]
Post subject:  Re: Sponge hardness table

That's a really handy scale, thanks igorponger :up: :up: :up:

Author:  iskandar taib [ 28 Dec 2017, 02:25 ]
Post subject:  Re: Sponge hardness table

I think he's right - the durometer is actually using scale A. That sheet of Sriver we were discussing earlier was measured at 53 degrees. If that's Shore C it'd be equivalent to 85-87 Shore A. And according to Wikipedia these inline skate wheels (you know how hard THEY are.. a LOT harder than any Sriver):

Image

are 83 and 85 Shore A.

https://en.wikipedia.org/wiki/Shore_durometer

Iskandar

Author:  igorponger [ 12 Mar 2018, 09:41 ]
Post subject:  Re: Sponge hardness table



Is this TARGET H51* rubber as hard as is indicated on the package? Looking forward to hear from Haggisv.

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