Glass Filled Filament

About glass filled filament

Glass filled filament is a base plastic reinforced with chopped glass fibre. The glass makes parts stiffer and more dimensionally stable and reduces warping, and it is less brittle than carbon fibre filled material. We stock glass filled PETG, ABS, ASA, PC and nylon PA12 in 1.75 mm on plastic spools.

Glass fibre or carbon fibre

Both stiffen a part and cut warping. Carbon fibre gives the highest stiffness and a dark matte finish. Glass fibre gives a little less stiffness but better impact resistance, comes in more colours and does not conduct electricity. For enclosures, housings and parts that take knocks, glass filled is often the better fit.

Printing glass filled filament

Glass fibre is abrasive, so use a hardened steel or other wear resistant nozzle, 0.4 mm or larger. Temperatures follow the base plastic. ABS GF, ASA GF and PC GF want an enclosure, and nylon GF needs to be dried well before printing.

Print settings

Nozzle typeHardened steel or similar
Nozzle size0.4 mm minimum, 0.6 mm preferred
TemperaturesAs for the base plastic
EnclosureRecommended for ABS, ASA and PC grades

Data sheets for the filled grades are in the TDS library, and free slicer profiles are available.

Common questions

What is glass filled filament used for?

Glass filled filament is used for stiff, dimensionally stable functional parts such as housings, brackets, enclosures and fixtures. The glass fibre reduces warping during printing and creep under load. Glass filled parts also handle impact better than carbon fibre filled parts.

Does glass filled filament need a hardened nozzle?

Glass filled filament needs a hardened steel or other wear resistant nozzle. Glass fibre is abrasive and will wear a brass nozzle quickly. A 0.6 mm nozzle is a safe choice because fibre filled filament can clog smaller nozzles.

Is glass fibre filament better than carbon fibre filament?

Glass fibre filament and carbon fibre filament suit different jobs. Carbon fibre filament is stiffer and lighter. Glass fibre filament is tougher under impact, does not conduct electricity and comes in more colours. Choose by whether the part needs maximum stiffness or more toughness.