ELASTOSIL® RT 625 A/B and MinghuiLink RTV-4125 are both 25 Shore A addition-cure mold silicones, but they target different production needs. RT 625 emphasizes mechanical performance, extended working time and composite or vacuum-bag molding, while RTV-4125 offers simpler 1:1 mixing, lower component viscosity and faster routine curing.
Addition-Cure Silicone
Platinum-Cure Silicone
ELASTOSIL® RT 620 A/B and RTV-4115 are both soft silicones, but their primary strengths are different. RT 620 is the better fit for pad printing and repeated deformation, while RTV-4115 is better aligned with soft mold making, simpler 1:1 processing and higher tear resistance.
ELASTOSIL® RT 625 A/B and RTV-4125 are closely matched at 25 Shore A, making processing and performance more important than hardness alone.
The main processing difference is the mixing system and working time. RT 625 uses a 9:1 ratio with approximately 60 minutes of pot life, while RTV-4125 uses a simpler 1:1 ratio with approximately 35 minutes of working time. RT 625 offers more processing latitude; RTV-4125 is easier to proportion manually.
Viscosity also differs significantly. RT 625 publishes approximately 25,000 mPa·s for Part A, 900 mPa·s for Part B and 12,000 mPa·s for the mixed material, while RTV-4125 publishes approximately 4,700 and 4,400 mPa·s for its components. These figures use different measurement points and should not be treated as a direct mixed-viscosity comparison.
RT 625 has the stronger published mechanical profile, with 6.5 MPa tensile strength, 30 N/mm tear strength and 600% elongation, compared with 4.0±0.5 MPa, 26±0.5 N/mm and 460±50% for RTV-4125. This provides greater published mechanical margin for demanding molds and repeated use.
WACKER specifically positions RT 625 for composite molding, vacuum-bag molding and technical reproduction, while RTV-4125 is more broadly suited to reusable molds and casting. The practical choice is therefore between longer processing and higher published mechanical performance with RT 625, or simpler 1:1 handling, lower component viscosity and faster routine curing with RTV-4125.
| Technical Parameter | WACKER ELASTOSIL® RT 625 A/B | MinghuiLink RTV-4125 |
|---|---|---|
| Silicone Type | Addition-cure RTV-2 | Platinum-cure silicone |
| Color | Translucent | Translucent |
| Mix Ratio | 9:1 by weight | 1:1 by weight or volume |
| Shore Hardness | 25 Shore A | 25±1 Shore A |
| Viscosity | 25,000 mPa·s (Part A) | 4,700±200 mPa·s (Part A) |
| Working / Pot Life | 60 min | 35 min |
| Demold / Cure Time | 12 h tack-free | 5 h cure |
| Tensile Strength | 6.5 MPa | 4.0±0.5 MPa |
| Tear Strength | 30 N/mm | 26±0.5 N/mm |
| Elongation | 600% | 460±50% |
| Shrinkage | <0.1% | ≤0.1% |
| Temperature Resistance | Not publicly listed as an equivalent numerical service rating | Up to 250°C / 482°F |
| Typical Applications | Composite molding, vacuum-bag molding, reproduction molds and technical molding | Reusable molds, resin casting and general medium-hardness mold making |
| Technical Data Sources | ELASTOSIL® RT 625 A/B | RTV-4125 |
| Key Factor | WACKER ELASTOSIL® RT 625 A/B | MinghuiLink RTV-4125 | What It Means |
|---|---|---|---|
| Hardness | 25 Shore A | 25±1 Shore A | Both target essentially the same A25 hardness range. |
| Mix Ratio | 9:1 | 1:1 | RTV-4125 is simpler for manual proportioning. |
| Working Time | 60 min | 35 min | RT 625 provides more processing time for larger or more complex molds. |
| Component Viscosity | 25,000 / 900 mPa·s | 4,700 / 4,400 mPa·s | RTV-4125 has much lower and more balanced component viscosities; measurement points differ. |
| Tensile Strength | 6.5 MPa | 4.0±0.5 MPa | RT 625 publishes the higher tensile-strength value. |
| Tear Strength | 30 N/mm | 26±0.5 N/mm | RT 625 publishes the higher numerical tear-strength value. |
| Elongation | 600% | 460±50% | RT 625 provides greater published stretch capability. |
| Application Positioning | Composite, vacuum-bag and technical molding | General reusable mold making and casting | RT 625 has the more specific industrial-tooling positioning. |
| Routine Turnaround | 12 h tack-free | 5 h cure | RTV-4125 is better aligned with faster routine production based on the published endpoints. |
| Application | ELASTOSIL® RT 625 A/B | RTV-4125 |
|---|---|---|
| General Reproduction Molds | Strong candidate | Strong candidate |
| Undercut Molds | Strong candidate | Strong candidate |
| Large / Complex Molds | Strong candidate | Suitable with adequate support |
| Composite Molding | Strong candidate | Suitable with application testing |
| Vacuum-Bag Molding | Strong candidate | Not specifically positioned |
| Resin Casting | Strong candidate | Strong candidate |
| Thin Mold Sections | Strong candidate | Strong candidate |
| Rapid Routine Production | Suitable | Strong candidate |
| Manual Small-Batch Mixing | Suitable with accurate weighing | Strong candidate |
| 3D-Printed Masters | Suitable with compatibility testing | Suitable with compatibility testing |
Tell us your application. We’ll recommend the right RTV-2 silicone and provide a sample for testing.
Competitor specifications are based on publicly available manufacturer documentation, with links to the original sources where available. Missing values are shown as “Not publicly listed” and are not estimated or inferred. Specifications may change, so always check the latest manufacturer documentation and conduct application-specific testing before production use. Product names and trademarks belong to their respective owners. This comparison is provided for technical and informational purposes only and is not endorsed by the brands mentioned.