PLA vs PTT
Polymer · grade comparison
PLA and PTT are both polymer grades. PTT is the stronger of the two: yield strength 58 MPa (8.41 ksi) against 48 MPa (6.96 ksi) for PLA, about 21% more; tensile strength follows at 62 MPa (8.99 ksi) vs 50 MPa (7.25 ksi). PTT is the more ductile: elongation 25% versus 5% for PLA, and PLA is harder (83 Shore D vs 78 Shore D). PLA is lighter (1.24 g/cm³ vs 1.32 g/cm³ for PTT) and PLA is stiffer (3.4 GPa vs 2.7 GPa). On the shop floor, PLA sits in a lower cost tier (budget, $) than PTT (standard, $$).
PLAChoose it when weight is the constraint, or when cost is the deciding factor.
PTTChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
PLA vs PTT: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Hardness, Rockwell M
Same in both: Shear Strength 45 MPa6.5 ksi
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Surface Resistivity
Comparative Tracking Index (CTI)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Weldability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | PLA | PTT |
|---|---|---|
| 3D printing | Yes | — |
| Default condition | Standard | — |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Conductive Coating | Yes | — |
| Dyeing (Nylon) | Yes | — |
| EMI Shielding Coating | Yes | — |
| Painting | Yes | — |
| Primer Coating | Yes | — |
| Soft Touch Coating | Yes | — |
| Tinted Coating | Yes | — |
| UV Coating | Yes | — |
| Vacuum Metallization | Yes | — |
| Waterproof Coating | Yes | — |
PLA vs PTT — frequently asked
Is PTT stronger than PLA?
Yes. PTT has a typical yield strength of 58 MPa (8.41 ksi) against 48 MPa (6.96 ksi) for PLA — about 21% more. Tensile strength is 62 MPa (8.99 ksi) vs 50 MPa (7.25 ksi).
Which is cheaper, PLA or PTT?
PLA is the lower-cost material: it sits in the budget tier ($) while PTT is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, PLA or PTT?
PTT, by a small margin. Both rate good for machinability — 65/100 against 60/100 for PLA.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PLA and PTT side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.