Meldin 7001 7021
Reinforced grade
7021 = meldin 7021
Standard bearing/wear grade: lower friction and better wear life in dry or marginally lubricated sliding than unfilled 7001.
Values for the 7021 condition
Other Meldin 7001 grades and fills
Meldin 7001 is listed in 5 conditions; see the grade overview at Meldin 7001.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Meldin 7211 | Lowest-friction / low-speed, high-load grade for unlubricated bushings, thrust washers and vane applications where stick-slip must be avoided. | — | 45 | 4 | 83 Shore D |
Meldin 7022 | High-graphite grade for high-load, high-PV dry bearings, seal rings and compressor parts where low wear and dimensional stability matter more than strength. | — | 52 | 3 | 87 Shore D |
7021This page Meldin 7021 | Standard bearing/wear grade: lower friction and better wear life in dry or marginally lubricated sliding than unfilled 7001. | — | 65 | 4.5 | — |
7001Default Meldin 7001 | Pick for maximum strength/elongation, best electrical insulation and cleanest (non-conductive, non-abrasive) polyimide; the general-purpose Vespel SP-1 substitute. | — | 86 | 7.5 | 88 Shore D |
Meldin 7030 | Highest stiffness/strength and lowest CTE of the family — use for structural, high-load or high-thermal-stability parts (not for soft-shaft bearings, abrasive to mating metal). | — | 120 | 2 | — |
What is Meldin 7001 7021?
Meldin 7001 7021 is Meldin 7001 in the 7021 grade — standard bearing/wear grade: lower friction and better wear life in dry or marginally lubricated sliding than unfilled 7001. Meldin 7001 7021 has a tensile strength of 65 MPa (9.43 ksi), stronger than 73% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.1 GPa (0.45 Msi). Meldin 7001 7021 has a density of 1.51 g/cm³ (0.0546 lb/in³), heavier than 88% of polymer grades. Its glass-transition temperature is 370°C (698 °F). 7001 is the default condition FabDigit quotes; 7021 is available on request or by drawing note.
Advantages
- High service temperature — 300°C (572 °F), better than 99% of polymer grades
- Conducts heat well — 0.87 W/m·K (0.503 BTU/hr·ft·°F), better than 99% of polymer grades
- Good UV / weathering resistance — 70/100, better than 83% of polymer grades
- Polishes to a fine finish — 70/100, better than 77% of polymer grades
Limitations
- Difficult to weld — 0/100, worse than 98% of polymer grades
- High embodied carbon — 16 kg CO₂/kg, worse than 98% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
- Heavy — 1.51 g/cm³ (0.0546 lb/in³), worse than 88% of polymer grades
- Limited ductility — 4.5%, worse than 75% of polymer grades
Meldin 7001 7021 properties
Typical room-temperature values for Meldin 7001 7021; 10 are specific to this condition. Other listed values are Meldin 7001 reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
Meldin 7001 7021 has a density of 1.51 g/cm³ (0.0546 lb/in³), heavier than 88% of polymer grades. Its glass-transition temperature is 370°C (698 °F).
Mechanical14
Meldin 7001 7021 has a tensile strength of 65 MPa (9.43 ksi), stronger than 73% of polymer grades. Elongation at break is 4.5% and the elastic modulus is 3.1 GPa (0.45 Msi).
Thermal10
Meldin 7001 7021 is rated for continuous service to 300°C (572 °F). It conducts heat at 0.87 W/m·K (0.503 BTU/hr·ft·°F), better than 99% of polymer grades. Thermal expansion is 49 µm/m·K (27.2 µin/in·°F).
Electrical5
Meldin 7001 7021 is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is very good.
Sustainability3
Producing a kilogram of Meldin 7001 7021 takes about 320 MJ of energy and emits 16 kg of CO₂ — more than 98% of polymer grades. Typical recycled content is 0%.
Manufacturability4
Meldin 7001 7021's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (0/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Meldin 7001 7021
Is Meldin 7001 easy to machine?
Machines like a hard, brittle thermoset — sharp polished carbide or PCD tools, high speed with light feed, no coolant needed (dry cutting avoids moisture pickup); dust extraction recommended.
Can Meldin 7001 be welded?
Cannot be welded or heat-staked; join by mechanical fastening, press fit or high-temperature adhesive (surface plasma/etch prep improves bond).
Can Meldin 7001 be formed, bent or molded?
Not melt-processible — parts are direct-formed or isostatically molded and sintered by the producer, then finish-machined from shape stock; no injection molding or cold forming.
What surface finishes work on Meldin 7001?
Lapping/polishing to <0.4 µm Ra is practical for seal faces; anneal after heavy machining to relieve stress, and dry/bake before use in vacuum or precision-fit assemblies.
Meldin 7001 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.
| Element | Spec limit (wt %) |
|---|---|
| aromatic polyimide (PMDA/ODA-type condenunfilled 7001; filled 7000-series grades substitute 10–40% graphite, PTFE or carbon fiber | balance |
Meldin 7001 7021 — frequently asked
What is Meldin 7001 7021 used for?
Meldin 7001 7021 is typically used for high-temperature seals, semiconductor process rings and aerospace insulating components. In short: 300 °C machinable polymer; vespel SP-1 alternative; unfilled polyimide shape stock.
What is the tensile strength of Meldin 7001 7021?
Meldin 7001 7021 has a typical tensile strength of 65 MPa (9.43 ksi) — stronger than 73% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is Meldin 7001 7021 easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machines like a hard, brittle thermoset — sharp polished carbide or PCD tools, high speed with light feed, no coolant needed (dry cutting avoids moisture pickup); dust extraction recommended.
Can Meldin 7001 7021 be welded?
Not readily — weldability is rated not recommended (0/100). Cannot be welded or heat-staked; join by mechanical fastening, press fit or high-temperature adhesive (surface plasma/etch prep improves bond).
What surface finishes work on Meldin 7001 7021?
Lapping/polishing to <0.4 µm Ra is practical for seal faces; anneal after heavy machining to relieve stress, and dry/bake before use in vacuum or precision-fit assemblies.
Can Meldin 7001 7021 be formed, bent or molded?
Not melt-processible — parts are direct-formed or isostatically molded and sintered by the producer, then finish-machined from shape stock; no injection molding or cold forming.
What is the maximum service temperature of Meldin 7001 7021?
Meldin 7001 7021 is rated for continuous use to about 300°C (572 °F), and briefly to 480°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Meldin 7000 Series Polyimide Shapes — property tables — Saint-Gobain Performance Plastics (2022)
- Vespel SP-1 / SP-21 / SP-22 / SP-211 Design Handbook (comparison baseline) — DuPont (2019)
- Engineered Materials Handbook Vol. 2 — Engineering Plastics (polyimide) — ASM International (1988)
- ASTM D6456 / D638 / D790 / D648 / D257 test methods — ASTM (2020)
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.