POM-H HI ST vs POM-H HI T
Polymer · POM-H HI grade comparison
POM-H HI ST and POM-H HI T are two grades of the same polymer grade, POM-H HI: ST (solution annealed) versus T (moderately toughened homopolymer). The chemistry is identical, so every difference below comes from the condition. POM-H HI T is the stronger of the two: yield strength 52 MPa (7.54 ksi) against 45 MPa (6.53 ksi) for POM-H HI ST, about 16% more; tensile strength follows at 52 MPa (7.54 ksi) vs 45 MPa (6.53 ksi). In exchange, POM-H HI ST is the more ductile: elongation 220% versus 130% for POM-H HI T, and POM-H HI T is harder (76 Shore D vs 72 Shore D). POM-H HI T is stiffer (2 GPa vs 1.4 GPa).
POM-H HI STChoose it when the part is bent, formed or impact-loaded.
POM-H HI TChoose it when strength drives the design.
POM-H HI ST vs POM-H HI T: 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
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Same in both: Shear Modulus 0.5 GPa0.07 Msi · Poisson's Ratio 0.4 · Compressive Strength 45 MPa6.5 ksi · Compressive Modulus 1.4 GPa0.2 Msi · Shear Strength 45 MPa6.5 ksi · Fracture Toughness (K_IC) 6.5 MPa·√m5.9 ksi·√in · Hardness, Rockwell M 58 HRM
Physical
Density and transition temperatures.
Density
Same in both: 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.
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Same in both: Thermal Conductivity 0.25 W/m·K0.14 BTU/hr·ft·°F · 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 · Vicat Softening Point (B50) 158°C316 °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
Mold Shrinkage
Same in both: Weldability 45 / 100 · Formability (cold) 60 / 100 · Polishability 55 / 100 · Melt Flow Rate 1.5 g/10 min · Processing Melt Temperature (typ.) 215°C419 °F · 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 ST vs POM-H HI T — frequently asked
Is POM-H HI T stronger than POM-H HI ST?
Yes. POM-H HI T has a typical yield strength of 52 MPa (7.54 ksi) against 45 MPa (6.53 ksi) for POM-H HI ST — about 16% more. Tensile strength is 52 MPa (7.54 ksi) vs 45 MPa (6.53 ksi).
Which grade does FabDigit quote by default, ST or T?
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 is easier to machine, POM-H HI ST or POM-H HI T?
POM-H HI T, by a small margin. Both rate very good for machinability — 78/100 against 72/100 for POM-H HI ST.
Ready to make it?
Upload a CAD file and FabDigit prices the part in POM-H HI ST and POM-H HI T 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.