Bambu Lab ABS-GF Filament 1.75mm 1kg

ABS with glass fibre through it. The fibre makes it substantially stiffer and more dimensionally stable than plain ABS, and pushes heat resistance higher again. It also gives a smooth matte finish with a faint micro-sparkle that hides layer lines — unusual for an engineering material to look this good.

Good for mechanical parts that need to hold their shape, and for decorative pieces where you want the finish without post-processing.

Enclosure, hardened nozzle, and no AMS Lite. ABS still needs a 45–60°C chamber, and glass fibre is abrasive — Bambu specify a hardened steel or tungsten carbide nozzle, 0.4mm or larger, with 0.6mm recommended. Not compatible with the open-frame A-series.

At a glance

The trade, stated plainly

You gain stiffness and heat resistance. Young's modulus goes from plain ABS's 2200 to 3160 MPa, bending stiffness from 1880 to 2860, and Vicat softening from 94 to 103°C. Heat deflection at 0.45 MPa reaches 99°C. Parts hold their shape under load and under heat far better, and warp noticeably less on the plate.

You lose impact resistance, and it is not a small loss. Unnotched impact falls from 39.3 to 14.5 kJ/m², and notched from 21.5 to 4.2. That notched figure is a fifth of plain ABS. Glass fibre makes a material rigid, and rigid materials crack rather than bend. If the part will be dropped, knocked or clamped, plain ABS is the safer choice.

Put simply: ABS-GF for a bracket that must not flex, plain ABS for a housing that must not shatter.

Printing it well

Use liquid glue on a Smooth PEI plate. That is Bambu's specific recommendation for this material — liquid glue rather than a stick, and the smooth plate rather than textured. The Cool Plate SuperTack is not compatible.

Layer direction matters more than usual. Stiffness drops from 3160 MPa in plane to 2250 across layers, and breaking elongation from 6.3% to 2.3% — so a part stressed across its layers is both weaker and far less forgiving. Orient accordingly.

Ventilate. Same as plain ABS — styrene while printing. Enclosure shut, room aired.

Annealing: 80–90°C for 6 to 12 hours. Test on a sample first; larger parts can distort.

Storage

Bambu specifies under 20% RH, sealed with desiccant, and 80°C for 8 hours to dry. A dryer that only reaches 70°C is not enough for this material.

As filament takes on moisture you'll hear popping at the nozzle, then see stringing and rough surfaces. With a fibre-filled material the surface finish suffers first, which is usually why you chose it — so keep it dry.

Bambu's usage guide for the glass-fibre grades covers handling, warping and advanced tuning: ABS-GF / PA6-GF Usage Guide