POM-H HI HF vs POM-H HI ST
Polymer · POM-H HI grade comparison
POM-H HI HF and POM-H HI ST are two grades of the same polymer grade, POM-H HI: HF (high-flow toughened injection grade) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. POM-H HI HF is the stronger of the two: yield strength 53 MPa (7.69 ksi) against 45 MPa (6.53 ksi) for POM-H HI ST, about 18% more; tensile strength follows at 53 MPa (7.69 ksi) vs 45 MPa (6.53 ksi). In exchange, POM-H HI ST is the more ductile: elongation 220% versus 90% for POM-H HI HF, and POM-H HI HF is harder (78 Shore D vs 72 Shore D). POM-H HI HF is stiffer (2.2 GPa vs 1.4 GPa) and POM-H HI HF conducts heat better (0.28 W/m·K vs 0.25 W/m·K).
POM-H HI HFChoose it when strength drives the design.
POM-H HI STChoose it when the part is bent, formed or impact-loaded.
POM-H HI HF vs POM-H HI ST: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Same in both: Shear Modulus 0.5 GPa0.07 Msi · Poisson's Ratio 0.4 · Compressive Modulus 1.4 GPa0.2 Msi
Physical
Density and transition temperatures.
Same in both: Density 1.34 g/cm³0.05 lb/in³ · Melting Temperature (Tm) 178°C352 °F · Glass Transition (Tg) -60°C-76 °F · Water Absorption (24 h) 0.25% · Water Absorption (Saturation) 0.9%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Same in both: Specific Heat Capacity 1,500 J/kg·K0.36 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 125 µm/m·K69.4 µin/in·°F · Min Service Temperature -50°C-58 °F · Limiting Oxygen Index 15% · Max Service Temperature (short-term) 130°C266 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · Dielectric Strength 18 kV/mm457 V/mil · Dielectric Constant (1 MHz) 3.7 · Dissipation Factor (1 MHz) 0.005 · Volume Resistivity 1×10¹⁴ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 68 / 100 · UV / Weathering Resistance 30 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Melt Flow Rate
Processing Melt Temperature (typ.)
Same in both: Polishability 55 / 100 · Mold Shrinkage 2% · Mold Temperature (typ.) 90°C194 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 92 MJ/kg39,553 BTU/lb · Embodied Carbon (primary production) 4.4 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 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.
POM-H HI HF vs POM-H HI ST — frequently asked
Is POM-H HI HF stronger than POM-H HI ST?
Yes. POM-H HI HF has a typical yield strength of 53 MPa (7.69 ksi) against 45 MPa (6.53 ksi) for POM-H HI ST — about 18% more. Tensile strength is 53 MPa (7.69 ksi) vs 45 MPa (6.53 ksi).
Which grade does FabDigit quote by default, HF or ST?
ST is the default POM-H HI condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which welds better, POM-H HI HF or POM-H HI ST?
POM-H HI ST. Its weldability rates fair (45/100) against fair (38/100) for POM-H HI HF.
Ready to make it?
Upload a CAD file and FabDigit prices the part in POM-H HI HF and POM-H HI ST 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.