Everyone picks a double-sided tape by its maximum temperature. That is the wrong criterion, and it is why adhesive mounts come off. What decides whether a bond survives is how long it holds under a continuous load, and on that the spread between tapes in the same price bracket is two orders of magnitude.
Load over time: the number that matters
A static shear test tells you how many hours a bond carries a constant weight before it creeps and lets go. Same price bracket, completely different answers.
| Adhesive | Code | Holds under continuous load | Base |
|---|---|---|---|
| Standard | AS | under 100 hours | synthetic rubber on PE foam |
| Standard acrylic | CS | under 100 hours | acrylic |
| Special | AP | over 5,000 hours | rubber, high hold |
| Special acrylic | CX | 168 hours declared on the data sheet | modified acrylic |
| High performance | CP | full strength 24 hours after application | acrylic |
If the mount carries a hanging bundle, or anything that pulls on it all day every day, AS and CS are the wrong answer even where the temperature is mild. That single distinction is worth more than any temperature table.
Surface energy: why it sometimes will not stick at all
An adhesive wets a surface only if the surface energy of the substrate is higher than the surface tension of the adhesive. Below roughly 36 dyne/cm, ordinary tapes do not wet properly and the bond is weak whatever you do.
| Substrate | Surface energy (reference values) | Ordinary tape |
|---|---|---|
| PP, polypropylene | about 29 dyne/cm | no |
| PE, polyethylene | about 31 dyne/cm | no |
| ABS | about 42 dyne/cm | yes |
| Polycarbonate | about 46 dyne/cm | yes |
| PA 6.6 | about 46 dyne/cm | yes |
| Painted or bare steel | well above the threshold | yes |
On PP and PE you need a tape formulated for low surface energy plastics. Tell us the substrate and we will tell you which one, or tell you honestly that adhesive is not the right route and a screw mount is.
Temperature, read correctly
The working temperature of the part is not the temperature of the polymer: it is the narrower of the two, polymer and adhesive. A PA 6.6 mount is good to +85 °C, but with standard AS adhesive it stops at +70 °C, because the adhesive sets the limit. With standard acrylic CS the same part reaches +100 °C and the plastic takes over again.
| Adhesive | Code | Service temperature |
|---|---|---|
| Standard | AS | -25 to +70 °C |
| Special | AP | -40 to +60 °C |
| Standard acrylic | CS | -40 to +100 °C |
| Special acrylic | CP | -30 to +105 °C |
Application temperature is a separate figure. Most of these tapes need to be applied above about +10 °C. Applying in a cold workshop in January and blaming the tape in March is the most common failure we see.
What we measured ourselves
On a 1104 mount, 19 x 19 mm, with standard adhesive on bare unpainted metal, we measured roughly 110 N in tension, which is over 30 N per square centimetre. The bond is not at full strength in the first minute: it keeps growing over the following days. Method and figures are in how strong an adhesive mount really is.
How to choose, in three questions
- Is there a continuous load on the mount? If yes, rule out AS and CS straight away.
- What is the substrate? If it is PP or PE, you need a dedicated low surface energy tape.
- What temperature, and at what temperature will it be applied? Two different numbers, both of them decide.
