TPE · hardness band
TPE Shore A 40
Properties of the Shore A 40 condition, compared with the other TPE grades.
Choose for low-closure-force gaskets, soft-touch grips and bellows where sealing on light load is critical.
What is TPE Shore A 40?
TPE Shore A 40 is TPE heat treated to Shore A 40 — choose for low-closure-force gaskets, soft-touch grips and bellows where sealing on light load is critical. TPE Shore A 40 has a tensile strength of 5 MPa (0.653 ksi), weaker than 82% of polymer grades. Elongation at break is 400% and the elastic modulus is 0 GPa (3.63×10⁻⁴ Msi). TPE Shore A 40 has a density of 0.94 g/cm³ (0.034 lb/in³), lighter than 76% of polymer grades. Its glass-transition temperature is -55°C (-67 °F). Shore A 30 to Shore A 90 is the default condition FabDigit quotes; Shore A 40 is available on request or by drawing note.
Advantages
- Forms and bends easily — 90/100, better than 92% of polymer grades
- Ductile — tolerates forming and impact — 400%, better than 86% of polymer grades
- Good UV / weathering resistance — 70/100, better than 83% of polymer grades
- Lightweight — 0.94 g/cm³ (0.034 lb/in³), better than 76% of polymer grades
Limitations
- Hard to polish — 20/100, worse than 95% of polymer grades
- Low stiffness — 0 GPa (3.63×10⁻⁴ Msi), worse than 94% of polymer grades
- Difficult to machine — 25/100, worse than 93% of polymer grades
TPE Shore A 40 properties
Typical room-temperature values for TPE Shore A 40 — 9 properties are specific to this condition; the rest are grade-level values shared by every TPE grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical5
TPE Shore A 40 has a density of 0.94 g/cm³ (0.034 lb/in³), lighter than 76% of polymer grades. Its glass-transition temperature is -55°C (-67 °F).
Mechanical11
TPE Shore A 40 has a tensile strength of 5 MPa (0.653 ksi), weaker than 82% of polymer grades. Elongation at break is 400% and the elastic modulus is 0 GPa (3.63×10⁻⁴ Msi).
Thermal8
TPE Shore A 40 is rated for continuous service to 100°C (212 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 200 µm/m·K (111.1 µin/in·°F).
Electrical5
TPE Shore A 40 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 73% of polymer grades. UV resistance is very good.
Sustainability4
Producing a kilogram of TPE Shore A 40 takes about 95 MJ of energy and emits 3.6 kg of CO₂ — less than 70% of polymer grades. Typical recycled content is 5%.
Manufacturability8
TPE Shore A 40's machinability is poor (25/100, worse than 93% of polymer grades); weldability good (65/100); formability excellent (90/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other TPE grades and fills
TPE is also supplied in 12 other conditions. The full side-by-side table is on the TPE overview.
- Shore A 30 to Shore A 90DefaultDefault catalogue entry covering the standard soft-to-hard injection grades; pick a specific Shore point when sealing force or feel matters.8 MPa tensile
- Shore D 40Semi-rigid grade for structural flexible parts, air-duct bellows and living-hinge components replacing soft PP.23 MPa tensile
- Shore A 90Top of the Shore A range for stiff bellows, pipe seals and parts needing near-rigid feel with some flex.17 MPa tensile
- Shore A 80Use where higher stiffness, abrasion and load support are needed, e.g. wheels, dust boots, semi-rigid seals.12 MPa tensile
- Shore A 70Workhorse hardness for automotive weather-seal inserts, plugs, bushings and durable grips.9 MPa tensile
- FR V-0Pick for cable jackets, connector seals and appliance parts requiring UL 94 V-0 without halogens.7 MPa tensile
- Shore A 55Balanced softness and tear strength for overmolded handles, cable strain reliefs and static seals.6 MPa tensile
- Shore A 40Choose for low-closure-force gaskets, soft-touch grips and bellows where sealing on light load is critical.5 MPa tensile
Working with TPE Shore A 40
Is TPE easy to machine?
Soft grades smear and tear — use sharp positive-rake tools, high speed with low feed, water-jet or die-cutting; freeze fixturing helps on Shore A <60.
Can TPE be welded?
Hot-plate, hot-air and IR welding to itself and to PP work well; ultrasonic welding is unreliable because the soft phase damps energy — adhesive bonding needs primer or plasma/corona pre-treatment.
Can TPE be formed, bent or molded?
Dry 1–2 h at 70–80 °C if wet, melt 180–235 °C, mold 20–60 °C, use generous gates/short shot paths, expect 1–3 % shrinkage and design for 2K adhesion or mechanical interlock in overmolding.
What surface finishes work on TPE?
Surface is defined by tool texture (EDM/laser texture reproduces well); no plating or anodizing — use in-mold color, laser marking or pad printing with elastomer-compatible inks.
TPE chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| polypropylene (PP hard phase)continuous thermoplastic matrix; sets Tm and stiffness | 25 – 50 | 35 |
| paraffinic process oilsoftener; higher oil = lower Shore A and lower oil resistance | 5 – 35 | 17 |
| filler (talc / CaCO3 / ATH in FR grades)0 in natural grades; ATH used for halogen-free V-0 | 0 – 40 | 2 |
| additives (antioxidant, UV stabilizer, p | 0.5 – 3 | 1.5 |
| EPDM rubber (dynamically vulcanized) or elastic phase; EPDM/TPV for heat+set, SEBS for feel and cost | ≥ 30 (balance) | — |
TPE Shore A 40 — frequently asked
What is TPE Shore A 40 used for?
TPE Shore A 40 is typically used for overmoulded tool and appliance grips, static seals and gaskets, automotive interior weatherstrip, cable jackets and strain reliefs, soft-touch consumer electronics surfaces and grommets and bellows. In short: rubber-like flexibility.
What is the tensile strength of TPE Shore A 40?
TPE Shore A 40 has a typical tensile strength of 5 MPa (0.653 ksi) — weaker than 82% of polymer grades. Strength varies by condition: see the 13 listed tempers.
Is TPE Shore A 40 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of polymer grades). Soft grades smear and tear — use sharp positive-rake tools, high speed with low feed, water-jet or die-cutting; freeze fixturing helps on Shore A <60.
Can TPE Shore A 40 be welded?
Yes — weldability is rated good (65/100). Hot-plate, hot-air and IR welding to itself and to PP work well; ultrasonic welding is unreliable because the soft phase damps energy — adhesive bonding needs primer or plasma/corona pre-treatment.
What surface finishes work on TPE Shore A 40?
Surface is defined by tool texture (EDM/laser texture reproduces well); no plating or anodizing — use in-mold color, laser marking or pad printing with elastomer-compatible inks.
Can TPE Shore A 40 be formed, bent or molded?
Dry 1–2 h at 70–80 °C if wet, melt 180–235 °C, mold 20–60 °C, use generous gates/short shot paths, expect 1–3 % shrinkage and design for 2K adhesion or mechanical interlock in overmolding.
What is the maximum service temperature of TPE Shore A 40?
TPE Shore A 40 is rated for continuous use to about 100°C (212 °F), and briefly to 135°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in TPE Shore A 40?
Yes — TPE Shore A 40 is available for injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ISO 18064 — Thermoplastic elastomers, nomenclature and abbreviated terms — ISO (2014)
- ASTM D412 / D2240 / D624 / D395 — tensile, durometer, tear, compression set of elastomers — ASTM (2021)
- Santoprene TPV product family data (8000/100 series) — ExxonMobil / Celanese (2023)
- THERMOLAST K / HIPEX TPE compound datasheets — KRAIBURG TPE (2023)
- CAMPUS plastics — TPE-V / TPE-S injection grades — CWFG (2024)
- Handbook of Thermoplastic Elastomers / ASM Engineering Plastics — Elsevier / ASM International (2007)
- TPE/TPV (2026)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.