The material list for printing is long and most of it is irrelevant to any given part, because the process narrows it first. Once you know whether the part will be extruded, cured, sintered or melted, the choice collapses to a handful of options, and the deciding property is usually temperature, toughness or chemical exposure rather than strength.
Filament materials
PLA is cheap, stiff, easy and softens in a warm car. PETG is tougher, prints almost as easily and resists chemicals better. ABS is stronger in heat and warps as it prints. ASA is ABS with ultraviolet stability for outdoor use. Nylon is tough and absorbs moisture. Polycarbonate is very strong and demands a hot enclosure. Filled variants of all of these add stiffness and abrade nozzles.
Resin materials
Standard resins are for appearance and detail and are brittle. Tough and durable resins approximate the behaviour of common thermoplastics and are the ones to ask for on functional parts. High temperature resins survive heat for tooling and testing. Clear resins polish to genuine transparency. Castable resins burn out cleanly for investment casting. Flexible resins cover soft parts.
Powder and metal
Sintered nylon is the functional workhorse: tough, isotropic enough to test with, needs no supports. Filled and elastomeric nylon powders extend the range. In metals the practical list is stainless and tool steels, aluminium alloys, titanium alloys, nickel superalloys and cobalt chrome, with the available set narrower on any single machine.
Choosing on what the part meets
Write down the maximum temperature, whether it carries load and for how long, what chemicals or cleaning agents touch it, whether it sees sunlight, and whether anything regulatory applies. Those five answers eliminate most of the list. Only then does cost sensibly choose between what remains, and by that point there are usually only two or three candidates.
Questions people ask about 3d print material
Which 3D printing material is strongest?
It depends on the property. Sintered nylon and polycarbonate lead among polymers for toughness; printed metals are in a different class entirely. Strength alone is rarely the deciding property.
What material should I use for a functional part?
Sintered nylon if you are buying from a bureau, a tough resin if the detail matters, or a machined thermoplastic if the load is serious.
Does material choice depend on the printer?
Entirely. The process narrows the list first, so decide the process from the requirement and then choose within what that process offers.
Which materials survive outdoors?
ASA among filaments, and stabilised grades elsewhere. Most standard photopolymers and unmodified ABS degrade in ultraviolet light within months.