3D Printing InfoFilament comparison
Magnetic vs TPU 98A
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Magnetic filamentSPECIALTY | TPU 98A / hard TPUFLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $64.99/kg median; $64.99–$64.99/kg across 1 dated product listings | $94.99/kg median; $34.99–$149.99/kg across 3 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | PLA loaded with ferromagnetic iron powder, so printed parts respond to magnets[1] | Hard thermoplastic polyurethane at 98 Shore A to about 60 Shore D — the rigid end of the TPU range[2][3] |
| Densityg/cm³ | About 1.85 (Proto-pasta manufacturer figure) — 1.5× standard PLA[1] | 1.23 (Fillamentum Flexfill 98A); 1.2 (Extrudr FLEX HARD, ISO 2781)[2][3] |
| Typical priceUSD/kg | 1 kg spools cluster near 65[4] | 1 kg spools cluster near 150[5] |
| Price range across brandsUSD/kg | 64–70 across formats; 1 kg spool 65, 500 g 70, 2 kg 70[4] | 95–150 across brands; Proto-pasta Clear Rigid TPU 95, Push Plastic TPU 100A 150[4][5] |
| Market availability1–5 | Niche, a handful of specialist brands[4] | Available from several mainstream brands[5][4][3] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 0.1, 0.5, 1 and 2 kg spools[4] | 1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[4][5] |
| Typical applications | Sensor targets, magnetic fixtures, and props that need to stick to a magnet or rust deliberately[1] | Drive belts, wheels, snap-fits and bumpers that need to flex but hold shape under load[2] |
| Printing Parameters | ||
| Nozzle temperature°C | 192 (Proto-pasta)[1] | 230–260 (Extrudr FLEX HARD)[3] |
| Bed temperature°C | 60 (Proto-pasta)[1] | 50–90 (Extrudr FLEX HARD)[3] |
| Enclosure / chamber requirement1–5 | Open frame is fine[1] | Open frame is fine[3] |
| Part cooling fan | Not documented | 0–30 % (Extrudr FLEX HARD)[3] |
| Bed surface & adhesion aid | Not documented | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[6][7] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | 1.6–2.4 at Proto-pasta's 20–30 mm/s on a 0.4 mm nozzle at 0.2 mm layer[1] | 4.6 (Extrudr FLEX HARD, stated max volumetric speed on a 0.4 mm nozzle)[3] |
| Warping tendency1–5 | Not documented | None[3] |
| Overall printing difficulty1–5 | Intermediate — dry filament and a tuned profile; slow, and brittle in filament form[1] | Easy — minor profile tuning; at this hardness the filament pushes like a rigid material[3] |
| Extruder requirement | Proto-pasta advises an extrusion width 0.05 mm larger than the nozzle and warns feeding is inconsistent below 0.4 mm and on Bowden machines[1] | Bowden viable at this hardness — Extrudr rates FLEX HARD to 100 mm/s where its soft grades cap lower[3] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass acceptable; hardened steel for volume work[1] | Brass fine indefinitely[3] |
| Abrasiveness1–5 | Moderately abrasive — metal fill[1] | Non-abrasive[3] |
| Nozzle clog risk1–5 | Moderate — needs dry filament and a clean nozzle; Prusa lists metal-filled composites as a higher clogging risk and recommends a 0.6 mm nozzle minimum[8] | Low[9] |
| Heat-creep / jam sensitivity1–5 | Not documented | Moderate — good heatbreak cooling needed[7] |
| Hotend requirement | Proto-pasta recommends a wear-resistant or larger nozzle for longer service intervals[1] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[6] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Not documented | Moderate — the TPU family absorbs readily; Extrudr specifies a 12 h dry at 60 °C for FLEX HARD[3][9] |
| Drying temperature & time | Not documented | 60 °C for 12 h (Extrudr FLEX HARD)[3] |
| Symptoms when wet | Not documented | Bubbling and popping at the nozzle, stringing and a rough surface[9] |
| Effect of moisture on strength | Polymaker rates PLA low-sensitivity and publishes no dry-versus-conditioned figures; absorbed water flashes to steam and shows as bubbling and poor layer adhesion[9] | Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[9] |
| Storage requirement | Not documented | Sealed with desiccant; often kept in a dryer during the print[9] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | Not documented | 53.7 at break (Fillamentum Flexfill 98A, DIN 53504)[2] |
| Elongation at break% | Not documented | 318 at break (Fillamentum Flexfill 98A, DIN 53504); Extrudr FLEX HARD 490 (ISO 527-2)[2][3] |
| Brittleness1–5 | Brittle — Proto-pasta describes the filament as more brittle than standard PLA and needing extra care in handling[1] | Very ductile — bends far before failing[2] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 98 Shore A and 60 Shore D (Fillamentum, ISO 7619-1); Extrudr FLEX HARD 58 Shore D (ISO 868)[2][3] |
| Creep resistance / sustained load1–5 | Not documented | Poor — no 98A creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[10] |
| Fatigue / repeated-flex resistance1–5 | Not documented | Excellent — living hinges viable[7] |
| Elasticity / flexibility1–5 | Rigid[1] | Semi-flexible[2][3] |
| Wear resistance & friction | Not documented | Abrasion 23 mm³ (Fillamentum, ISO 4649 method A) and 26 mm³ (Extrudr FLEX HARD, ISO 4649-A) — the best abrasion figures in the group[2][3] |
| Thermal Properties | ||
| Melting point / Vicat°C | Not documented | 190–210 melting (Extrudr FLEX HARD, ISO 3146-C); Vicat A 140 (ISO 306)[3] |
| Environment & Chemical | ||
| UV resistance1–5 | Not documented | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[7] |
| Outdoor durability | Deliberately rustable — Proto-pasta markets the iron content as oxidising when exposed to moisture[1] | Not documented |
| Chemical resistance | Not documented | Withstands industrial solvents and UV exposure (Polymaker)[7] |
| Food contact | Not documented | Not food safe without specific certification (Polymaker)[7] |
| Biodegradability / compostability | Not documented | Not biodegradable[7] |
| Recyclability | Not documented | Not accepted in household plastic collection[7] |
| Electrical & ESD properties | Ferromagnetic: Proto-pasta states it responds to magnets and behaves similarly to pure iron[1] | Not documented |
| Health & Safety | ||
| Fume toxicity1–5 | Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[11] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[11] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[11] | Open a window / occasional ventilation[11] |
| Post-Processing | ||
| Sanding & machining | Polishing and deliberate rusting are the intended finishes[1] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[7] |
| Gluing & solvent welding | Not documented | Cyanoacrylate bonds TPU; no common solvent welds it[7] |
| Vapour / chemical smoothing | Not documented | No practical vapour smoothing[7] |
| Support material pairing | Not documented | Polymaker warns TPU supports are often very difficult to remove[7] |
| Dimensional accuracy & detail | Not documented | Tear strength 170 kN/m (Fillamentum, ISO 34-1) and 175 kN/m (Extrudr FLEX HARD, ISO 34-1B)[2][3] |
| Solvents & Solubility | ||
| Soluble in | Chloroform dissolves the PLA matrix and leaves the iron powder behind; laboratory reagent, not workshop stock.[12][1] | DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[13] |
| Softened or crazed by | Acetone and ethyl acetate plasticise the matrix rather than dissolving it; water attacks the exposed iron.[12][1] | Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[13] |
| Solvent welding & smoothing agent | None — PLA has no workshop-safe solvent, and the iron loading blocks the surface flow smoothing needs.[12] | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[13] |
Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.
Sources for this comparison
- Magnetic Iron PLA — product page and technical data Proto-pasta · 2026-08 · tds
- Flexfill TPU 98A Technical Data Sheet Fillamentum · 2019-08 · tds
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- Push Plastic product catalogue Push Plastic · 2026-08 · vendor
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Composite materials with metal or wood particles Prusa Knowledge Base · 2026-08 · doc
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
- Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds