Glass-Filled Nylon (PA-GF) prints at about 270 °C with a 80 °C bed and 0% part cooling. Usable range 250–290 °C nozzle, 60–100 °C bed. Needs an enclosure.
Slow, 20–40 mm/s, and slower on the first layer. Nylon needs dwell time to bond and the fill does not change that.
Bed surface
Garolite (G10), or PEI with a glue-stick separator.
Nozzle
Hardened steel, 0.6 mm. This is one of the most abrasive filaments a hobbyist will ever load — glass in a high-temperature carrier wears a brass nozzle visibly within one spool.
What bites people
This is the strongest part-making filament most hobbyists can realistically run — genuinely engineering-grade for gears, brackets and load-bearing hardware.
Shrinks roughly half as much as plain nylon, which is the whole point of the fill. Dimensional nylon parts should generally be filled.
Hardened steel nozzle is mandatory, not advisable.
Still absorbs water aggressively. A wet spool prints foamy and weak no matter how good the profile is.
Glass-filled nylon keeps more toughness than carbon-filled nylon, which goes stiffer but more brittle. For a part that gets impacted, glass is the safer choice.
Safety
Nozzle above 250 °C. Emissions are less studied than ABS — ventilate anyway.
Abrasive — hardened nozzle required.
Do not sand, drill or machine without a mask. Glass fibre dust is a respiratory irritant.