ABS-GF Glass-fiber-reinforced ABS (QIDI ABS-GF25)

ABS (acrylonitrile butadiene styrene) is the tough, heat-tolerant plastic of LEGO bricks, appliance housings and car interior trim. ABS-GF adds short, chopped glass fibers. QIDI's grade, ABS-GF25, is described on its product page as 25 % glass-fiber-reinforced ABS. The fibers make the plastic stiffer and, most importantly for printing, much less prone to shrinking and warping as it cools.

Plain ABS is notorious for curling at the corners and cracking between layers on large parts, because it shrinks noticeably as it cools. Glass fiber restrains that shrinkage. QIDI illustrates this with a side-by-side test: a bar it shows measuring 149.92 mm in ABS-GF25 against 149.47 mm in plain ABS, with the ABS-GF part described as having no warpage compared with standard ABS. That's a single vendor's own comparison rather than a standard test, but it matches what the material is designed to do.

On QIDI's comparison table, ABS-GF25 is modestly better than plain ABS Rapido across the board: HDT 87.0 °C against 85.0 °C at 0.45 MPa, bending strength 78.8 MPa against 77.5 MPa, and a clearly better between-layer tensile strength of 30.48 MPa against 24.35 MPa. So think of it as 'ABS that holds its shape', ideal for jigs, fixtures and housings, rather than a big leap in heat or strength.

QIDI doesn't publish a density or an XY tensile strength for ABS-GF25 in text; those values appear only in image tables we couldn't verify. We list only the numbers QIDI states in text.

Glass fiber adds stiffness and stability more than outright strength. QIDI's comparison table shows ABS-GF25's bending strength at 78.8 MPa, only slightly above plain ABS Rapido's, but in practice the fiber makes the part noticeably more rigid, so brackets and fixtures deflect less under load.

The bigger gain is between layers. FDM parts are anisotropic, meaning strength depends on direction: strongest along the printed lines (XY) and weakest across the layers (Z), where each layer is fused to the one below. QIDI lists ABS-GF25's Z tensile strength at 30.48 MPa against 24.35 MPa for plain ABS Rapido. Less shrinkage means less built-in stress pulling layers apart, so layer cracks on large parts are much less common.

Even so, Z remains the weak direction. We orient your part so the main bending or pulling loads run along the layers, and we'll tell you if a design forces a weak orientation. For hooks, tabs and clips, orientation often matters more than the material.

Glass-filled plastics are less ductile than unfilled ones. ABS-GF holds its shape under moderate loads and then breaks more suddenly than plain ABS, which tends to bend and whiten first. For parts that take impacts, plain ABS, PC or a nylon is usually tougher.

QIDI lists ABS-GF25's heat deflection temperature (HDT, the temperature at which a standard bar bends a set amount under load) at 87.0 °C at 0.45 MPa, as printed. That's about the same as plain ABS and well above PLA and PETG, but it is a short-term test value at a light load, not a safe working temperature for a loaded part.

Under continuous load, thermoplastics creep (slowly deform) below their HDT, so keep a margin for parts that carry weight while warm. As a guide, ABS-GF suits warm indoor machinery and sheltered car interiors; for anything near engines, heaters or hot process equipment, tell us and we'll suggest a higher-temperature composite.

QIDI marks annealing as not generally recommended for ABS-GF25, and we don't offer it for this material.

ABS-GF inherits ABS's main weakness: poor UV resistance. Sunlight breaks down the butadiene rubber in ABS, so the surface chalks and discolors and the part loses toughness, especially thin features. The glass fiber doesn't protect against this.

Indoors, behind glass that filters most UV, or under paint, ABS-GF lasts well. For anything outdoors in the sun, we recommend ASA-CF, which offers similar stiffness and better heat resistance with much better weathering.

ABS generally resists water, many dilute acids and alkalis, and many oils and greases, which suits machine and fixture applications. QIDI doesn't publish a chemical-resistance chart for ABS-GF25, so treat this as general guidance for ABS-family plastics.

Acetone dissolves ABS, and many other solvents, such as some paint thinners, fuels, brake fluid and aggressive degreasers, can soften or craze it. Isopropyl alcohol wipes are generally tolerated for short cleaning, but avoid soaking. If your part will see a particular fluid, tell us, and test a sample in that fluid before ordering a batch.

Finished ABS-GF parts absorb little water: QIDI lists 0.38 % saturated water absorption. They keep their size and stiffness in humid workshops, which is part of why they suit fixtures and tooling.

The filament itself must be dry to print well; QIDI marks drying as required and recommends desiccant storage. We dry it before printing and keep it sealed during jobs, so you don't need to do anything special with the finished parts.

ABS-GF prints with a matte, slightly textured surface that hides layer lines better than plain ABS. It looks functional and industrial rather than glossy, which suits tooling and housings well.

Glass fibers can leave a slightly rough feel, and a faint sparkle or lighter streaks may show in some colors. Surfaces printed against the build plate come out flattest; tell us which faces are cosmetic and we'll orient for them where strength allows.

QIDI offers ABS-GF25 in several colors, so unlike carbon-fiber grades you aren't limited to black. Availability varies; check the color list on your quote.

Vapor smoothing isn't something we offer for ABS-GF. The glass fibers prevent the glossy, sealed surface it gives on plain ABS, and the result is usually patchy. If you need a smooth cosmetic finish, plain ABS may be a better choice.

ABS-GF can be sanded, primed and painted. Sanding exposes fibers and leaves a fuzzy surface, so filler-primer before paint gives the best result. Wear a mask if you sand glass-filled parts yourself, as the dust is irritating.

Heat-set brass inserts work well in ABS-GF and are our standard for repeated-assembly threads. Drilling, reaming and tapping are all possible; the fibers wear tools faster than plain plastic. We don't anneal ABS-GF, in line with QIDI's guidance.

Dimensional stability is ABS-GF's main selling point. Glass fiber reduces shrinkage, so large, flat parts come out flatter and closer to size than in plain ABS. QIDI's own side-by-side measurement shows the ABS-GF25 part closer to its nominal length than the plain ABS one, and our heated chamber further reduces warp.

All FDM parts show some variation: holes print slightly undersized and outer dimensions slightly oversized. For fits that matter, mark critical dimensions on your drawing; we can compensate in the model or ream holes after printing. For fixtures with locating pins or datums, we recommend approving a first article before a batch.

The fiber-safe nozzle minimum of 0.4 mm limits fine detail. Small text, sharp internal corners and thin ribs will be softer than in PLA.