General Purpose D75
Grade
D75 = shore D 75
Rigid unfilled PU for machinable tooling blocks, jigs, fixtures and cast prototype parts.
Values for the D75 condition
Other General Purpose grades and fills
General Purpose is listed in 15 conditions; see the grade overview at General Purpose.
Compare all 15 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
slabstock/moulded PU foam (~30–60 kg/m³) | For cushioning, seating, packaging and acoustic absorption where load-bearing is minimal. | 0.15 | 150 | ||
closed-cell PU/PIR insulation (~30–60 kg/m³) | Best-in-class insulation core for panels, cold-chain and spray-applied insulation; not a load-bearing structural material. | 0.3 | 6 | ||
Shore A 40 | Choose for soft printing/conveying rolls, vibration pads and gaskets needing high conformability. | 18 | 700 | 10 Shore D | |
Shore A 60 | Good compromise of cushioning and load capacity for rolls, wipers and shock pads. | 30 | 620 | 16 Shore D | |
FR V-0 | Specify for cable jacketing, rail/transport interiors and electrical parts needing UL 94 V-0. | 30 | 400 | 35 Shore D | |
ESD / antistatic polyurethane | Carbon-black or ionic-additive grade for rollers, wheels and mats in electronics and explosive-atmosphere areas. | 32 | 400 | 35 Shore D | |
Lubricated / low-friction PU | Pick where sliding wear or stick-slip is the problem — dynamic seals, wear strips, guide rails. | 34 | 350 | 38 Shore D | |
Shore A 70 | Standard hardness for drive rollers, scrapers and low-noise wheels. | 35 | 580 | 22 Shore D | |
TPU polyether-based | Use where parts see hot water, humidity or microbial attack, or must stay flexible below −40 °C. | 38 | 560 | 85 Shore A | |
GP-A80Default GP Shore A 80 | Default all-round grade for rollers, pads, bushings and seals needing high abrasion and tear resistance with useful flexibility. | 40 | 520 | 30 Shore D | |
TPU polyester-based | Melt-processable grade for injection-moulded and extruded parts (hose, cable jacket, wheels) needing top abrasion and oil resistance. | 45 | 500 | 35 Shore D | |
Shore A 90 | Pick for heavy-load wheels, mill liners, cyclone parts and stripper plates where abrasion and load dominate over flexibility. | 48 | 450 | 40 Shore D | |
Shore D 60 | For structural bushings, dies, prototype tooling and stripper/forming pads that must hold shape under high load. | 50 | 300 | 60 Shore D | |
D75This page Shore D 75 | Rigid unfilled PU for machinable tooling blocks, jigs, fixtures and cast prototype parts. | 55 | 30 | 75 Shore D | |
30% glass-fiber reinforced rigid PU / RIM | Structural RIM/cast grade for stiff, dimensionally stable housings and panels replacing sheet metal. | 80 | 4 | 82 Shore D |
What is General Purpose D75?
General Purpose D75 is General Purpose in the D75 grade — rigid unfilled PU for machinable tooling blocks, jigs, fixtures and cast prototype parts. General Purpose D75 has a tensile strength of 55 MPa (7.98 ksi), stronger than 64% of polyurethane grades. Elongation at break is 30% and the elastic modulus is 1.7 GPa (0.247 Msi). General Purpose D75 has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 86% of polyurethane grades. Its glass-transition temperature is -35°C (-31 °F). GP-A80 is the default condition FabDigit quotes; D75 is available on request or by drawing note.
Advantages
- Readily welded — 15/100, better than 97% of polyurethane grades
- High service temperature — 90°C (194 °F), better than 86% of polyurethane grades
- Good UV / weathering resistance — 35/100, better than 83% of polyurethane grades
- Easy to machine — 75/100, better than 83% of polyurethane grades
- Forms and bends easily — 72/100, better than 75% of polyurethane grades
Limitations
- High mold shrinkage — 1.2%, worse than 97% of polyurethane grades
- Hard to polish — 30/100, worse than 82% of polyurethane grades
General Purpose D75 properties
Typical room-temperature values for General Purpose D75; 16 are specific to this condition. Other listed values are General Purpose reference data and may not represent this condition. Bars are the position among polyurethane grades.
Physical4
General Purpose D75 has a density of 1.2 g/cm³ (0.0434 lb/in³), heavier than 86% of polyurethane grades. Its glass-transition temperature is -35°C (-31 °F).
Mechanical10
General Purpose D75 has a tensile strength of 55 MPa (7.98 ksi), stronger than 64% of polyurethane grades. Elongation at break is 30% and the elastic modulus is 1.7 GPa (0.247 Msi).
Thermal8
General Purpose D75 is rated for continuous service to 90°C (194 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 83% of polyurethane grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).
Electrical7
General Purpose D75 is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 82% of polyurethane grades. UV resistance is fair.
Sustainability4
Producing a kilogram of General Purpose D75 takes about 105 MJ of energy and emits 5 kg of CO₂ — more than 64% of polyurethane grades. Typical recycled content is 3%.
Manufacturability6
General Purpose D75's machinability is very good (75/100, better than 83% of polyurethane grades); weldability poor (15/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with General Purpose D75
Is General Purpose easy to machine?
Machines like a tough rubber: use very sharp positive-rake carbide or single-flute tools, high surface speed with low feed pressure, air or water-mist cooling, and support thin walls to avoid deflection and tearing; hard D-scale grades cut almost like a rigid plastic.
Can General Purpose be welded?
Cast (thermoset) PU cannot be welded — join by adhesive bonding with polyurethane/epoxy or cyanoacrylate after abrasion and primer; TPU grades weld well by hot-plate, HF/ultrasonic and hot-air methods.
Can General Purpose be formed, bent or molded?
Open-cast, centrifugal or RIM processing of prepolymer at 70–110 °C mould temperature with post-cure 8–16 h at 100 °C; TPU is injection-moulded or extruded at 185–225 °C melt and must be dried 2–3 h at 80–100 °C to avoid hydrolysis and bubbles.
What surface finishes work on General Purpose?
Not platable or anodizable; parts are usually used as-cast or ground/lathe-finished, and can be painted with 2K polyurethane paints after solvent wipe and light abrasion — adhesion to metal cores requires blasting plus a PU bonding primer.
General Purpose 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 |
|---|---|---|
| MDI (4,4'-diphenylmethane diisocyanate)TDI or aliphatic HDI/H12MDI used in some grades | 20 – 40 | 30 |
| chain extender (1,4-butanediol / MOCA / sets hard-segment content and hardness | 3 – 10 | 6 |
| catalyst, antioxidant, hydrolysis stabil | 0.2 – 2 | 1 |
| glass fiber0–30% in reinforced RIM/rigid variants | ≈ 0 | 0 |
| polyester or polyether polyoladipate polyester, PTMEG or PPG; determines hydrolysis and low-temperature behaviour | ≥ 50 (balance) |
General Purpose D75 — frequently asked
What is General Purpose D75 used for?
General Purpose D75 is typically used for housings, enclosures and fixtures. In short: everyday rigid cast PU; ABS-like feel.
What is the tensile strength of General Purpose D75?
General Purpose D75 has a typical tensile strength of 55 MPa (7.98 ksi) — stronger than 64% of polyurethane grades. Strength varies by condition: see the 15 listed tempers.
Is General Purpose D75 easy to machine?
Yes — machinability is rated very good (75/100, better than 83% of polyurethane grades). Machines like a tough rubber: use very sharp positive-rake carbide or single-flute tools, high surface speed with low feed pressure, air or water-mist cooling, and support thin walls to avoid deflection and tearing; hard D-scale grades cut almost like a rigid plastic.
Can General Purpose D75 be welded?
Not readily — weldability is rated poor (15/100). Cast (thermoset) PU cannot be welded — join by adhesive bonding with polyurethane/epoxy or cyanoacrylate after abrasion and primer; TPU grades weld well by hot-plate, HF/ultrasonic and hot-air methods.
What surface finishes work on General Purpose D75?
Not platable or anodizable; parts are usually used as-cast or ground/lathe-finished, and can be painted with 2K polyurethane paints after solvent wipe and light abrasion — adhesion to metal cores requires blasting plus a PU bonding primer.
Can General Purpose D75 be formed, bent or molded?
Open-cast, centrifugal or RIM processing of prepolymer at 70–110 °C mould temperature with post-cure 8–16 h at 100 °C; TPU is injection-moulded or extruded at 185–225 °C melt and must be dried 2–3 h at 80–100 °C to avoid hydrolysis and bubbles.
What is the maximum service temperature of General Purpose D75?
General Purpose D75 is rated for continuous use to about 90°C (194 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in General Purpose D75?
Yes — General Purpose D75 is available for urethane casting with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASM Engineered Materials Handbook, Vol. 2: Engineering Plastics — ASM International (1988)
- Polyurethane Handbook (Oertel) — Hanser (1994)
- Desmopan / Texin TPU product datasheets — Covestro (2023)
- Adiprene / Vibrathane cast prepolymer selector guides — LANXESS (Chemtura) (2022)
- Elastollan TPU material properties brochure — BASF (2023)
- CAMPUS plastics database — TPU records — CWFG (2024)
- ASTM D412 / D624 / D395 / D2240 rubber test methods — ASTM (2022)
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.