$ELASTOSIL<sup>®</sup> RT 623 A/B

Pourable, addition-curing, two-component silicone rubber for pad printing that vulcanizes at room temperature.


Main application: Making printing pads.


  • very good flow
  • high reactivity for fast demolding even if large amounts of silicone fluid are added
  • fast and non-shrink cure at room temperature which can be accelerated considerably by the application of heat
  • medium Shore A hardness (approx. 31)
  • high tear strength
  • long-term stability of the vulcanizate’s mechanical properties, particularly its hardness

Specific features of ELASTOSIL® RT 623 A/B

  • Crosslinking Property: Two-component
  • Product Type: Two-component
  • Specific Features: Excellent mechanical properties
  • Specific Features: Fast curing
  • Specific Features: Two-component
  • Vulcanizate: Excellent mechanical properties


All the information provided is in accordance with the present state of our knowledge. Nonetheless, we disclaim any warranty or liability whatsoever and reserve the right, at any time, to effect technical alterations. The information provided, as well as the product's fitness for an intended application, should be checked by the buyer in preliminary trials. Contractual terms and conditions always take precedence. This disclaimer of warranty and liability also applies particularly in foreign countries with respect to third parties' rights.

Base rubber for making printing pads.

ELASTOSIL® RT 623 A/B has been specially designed as a base material for making printing pads.

The vulcanizate’s high mechanical strength and long term stability of hardness make ELASTOSIL® RT 623 A/B an ideal base material for producing printing pads with excellent mechanical properties and long service life.


Important note:

The platinum catalyst is in component B.



A and B components may only be used together if they have the same batch number.


To ensure both optimum flow and homogeneity of the material, the components must be stirred thoroughly before they are removed or processed in their containers, in order to uniformly disperse any fillers that might have settled during storage.


Dilution charts:

The following table shows the hardness of ELASTOSIL® RT 623 A/B as a function of the added amount of Wacker Silicone Fluid AK 35 for Durometer Types Shore A and Shore 00.

 Please check also our brochures and info sheets.


The 'Best use before end' date of each batch is shown on the product label.

Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.

Sales and support

Wacker Chemical Corporation
3301 Sutton Road
Adrian, MI 49221-9397
United States
+1  888  922-5374 (Phone)

How can we help you?

  • Do you need help in choosing a product or do you require technical support? If so, please contact our experts.
Ask a question

Would you like a product sample?

You can request a product sample here.

Request sample

More products

Products Technical data
Viscosity, dynamic Tear strength Hardness Shore A Tensile strength Elongation at break
ELASTOSIL® M 4400 30000 mPa·s[1] - > 3 N/mm[4] > 3 N/mm[4] 23[5] 23[5] 2 N/mm²[6] 2 N/mm²[6] 250 %[7] 250 %[7]
ELASTOSIL® RT 402 - - > 3 N/mm[4] > 3 N/mm[4] 11[5] 11[5] 2 N/mm²[6] 2 N/mm²[6] 350 %[7] 350 %[7]
ELASTOSIL® RT 620 A/B 7000 mPa·s[2] 7000 mPa·s[2] ≥ 12 N/mm[4] ≥ 12 N/mm[4] 17[5] 17[5] 5 N/mm²[6] 5 N/mm²[6] 900 %[7] 900 %[7]
ELASTOSIL® RT 623 A/B 15000 mPa·s[3] - > 30 N/mm[4] > 30 N/mm[4] 31[5] 31[5] 7.5 N/mm²[6] 7.5 N/mm²[6] 700 %[7] 700 %[7]
ELASTOSIL® RT 629 A/B 14000 mPa·s[3] - 25 N/mm[4] 25 N/mm[4] 31[5] 31[5] 6 N/mm²[6] 6 N/mm²[6] 500 %[7] 500 %[7]
[1] Viscosity, dynamic after stirring | 23 °C | DIN EN ISO 3219,  [2] Viscosity, dynamic | 23 °C | ISO 3219,  [3] Viscosity, dynamic after stirring | 23 °C | ISO 3219,  [4] Tear strength | ASTM D 624 B,  [5] Hardness Shore A | ISO 868,  [6] Tensile strength | ISO 37,  [7] Elongation at break | ISO 37 


My media

My favorites

My products