How strong are 3D printed parts?

Stronger than most people expect. SLS nylon and MJF parts are tough and nearly isotropic; carbon-filled FDM and metal DMLS reach engineering-grade strength. FDM is directional and weaker between layers, so orientation matters. Name your loads and material and the shop advises.

What tolerances can 3D printing hold?

Roughly ±0.5% for FDM, ±0.2% for SLA and MJF, and ±0.1 to 0.2 mm for metal DMLS, each with a process minimum. For features tighter than that, shops print oversized and machine the critical face after. Call out the critical dimensions on your model.

Can I get metal 3D printed parts?

Yes. DMLS and SLM fuse metal powder into fully dense parts in aluminum, stainless, tool steel, titanium, and Inconel. They are usually stress-relieved, cut off the build plate, and machined on mating faces. Send the model and note critical tolerances.

Is 3D printing good for production?

For low volumes and complex parts, yes. SLS, MJF, and metal have no tooling cost, so hundreds of complex parts can beat molding on price and geometry is effectively free. Past a few thousand simple parts, injection molding or machining usually wins on unit cost.

What file formats should I send?

STEP is best because it keeps true geometry and units. STL and 3MF work for print-ready meshes. Include material, process (or the requirement), quantity, finish, and any critical dimensions or cosmetic faces.

Get quotes for custom 3D printed parts

Parts built layer by layer from filament, resin, or powder. No tooling, so complex geometry and one-off prototypes come fast, and low-volume production without a mold. Upload your 3D model and we'll source competitive quotes from qualified manufacturing partners.

Upload Files & Get Free Quotes

STEP · STL · IGES · DWG · DXF · PDF · and more

Uploads are secure & confidential

No CAD file?

Processes

3D Printing processes

Compare the specific processes and pick the right one for your part.

FDM / FFF

Fast, low-cost filament prototypes.

SLS

Strong nylon parts, no supports.

MJF

Production nylon, fine detail, fast batches.

Resin (SLA / DLP)

Smooth finish and the finest detail.

Metal (DMLS / SLM)

Fully dense end-use metal parts.

Metal Binder Jetting

Sintered metal parts, faster and lower cost.

Carbon DLS

End-use resin parts with isotropic properties.

PolyJet

Fine-detail, multi-material photopolymer parts.

Vapor Smoothing

Glossy, sealed, molded-like finish for prints.

How OpenSpindle works

We tap our partner network. You get the best-match quote.

Upload your part and we tap our network of partner shops to get you a competitive, all-in quote that is the best match for the job.

One upload

A CAD file or a sketch. That is the whole ask on your end.

Your best-match quote

Sourced from the partner shops set up for your exact part.

All-in, on your timeline

Machining, finishing, and shipping detailed to your turnaround.

Processes and materials our print shops run

Additive is chosen by process first: filament, resin, or powder, each with its own strengths and material set. Expand a process to compare its materials, or tell the shop the requirement and let it choose. If your material is not here, ask when you request a quote.

FDM / FFF

Filament

Molten thermoplastic extruded layer by layer. The workhorse for functional prototypes, jigs, and rugged low-cost parts.

8 materials

Best for: Functional prototypes, jigs and fixtures, tough end-use parts
Accuracy: ±0.5% (min ±0.5 mm)

Material	Properties	Tensile	Elong.	HDT	Best for	Cost
PLA	RigidDetail/Cosmetic	50 MPa	6%	55°C	Concept models, low-cost jigs	$
ABSDirectional: weaker between layers	ToughImpact	40 MPa	10%	98°C	Housings, functional prototypes	$
PETG	ToughChemical-resistant	50 MPa	8%	70°C	Brackets, guards, fluid parts	$
ASA	UV-stableTough	44 MPa	9%	95°C	Outdoor and automotive parts	$
NylonPA	ToughWear-resistant	48 MPa	30%	90°C	Gears, living hinges, snap-fits	$$
PolycarbonatePC	High-tempStructural	60 MPa	5%	110°C	Heat-resistant, load-bearing parts	$$
TPU95A	Flexible	30 MPa	450%	—	Gaskets, grips, seals	$$
CF-Nylon	StructuralRigid	70 MPa	4%	140°C	Stiff structural brackets, tooling	$$$

SLA / DLP

Resin

Liquid photopolymer cured by light for smooth surfaces and crisp fine detail. Best when finish and feature resolution matter.

7 materials

Best for: Fine detail, smooth cosmetic parts, casting patterns
Accuracy: ±0.2% (min ±0.15 mm)

Material	Properties	Tensile	Elong.	HDT	Best for	Cost
Standard	Detail/CosmeticRigid	65 MPa	6%	73°C	Cosmetic models, visual prototypes	$$
ToughABS-like	ToughImpact	46 MPa	48%	63°C	Snap-fits, housings, assemblies	$$
DurablePP-like	Wear-resistantFlexible	32 MPa	49%	45°C	Low-friction, wear parts, snap-fits	$$
High-Temp	High-tempRigid	58 MPa	3%	238°C	Heat-resistant fixtures, mold masters	$$$
Rigidglass-filled	RigidStructural	65 MPa	1%	218°C	Stiff jigs, thin walls, fixtures	$$$
Flexible80A	Flexible	9 MPa	120%	—	Grips, wearables, cushioning	$$
CastableBurns out clean; brittle by design	CastableDetail/Cosmetic	—	—	—	Investment casting patterns, jewelry	$$

SLS / MJF

Nylon powder

Nylon powder fused by laser or a binding agent, with no support structures. Strong, near-isotropic parts and dense nesting for low-volume production.

4 materials

Best for: Durable production parts, complex geometry, small batches
Accuracy: ±0.3% (min ±0.3 mm)

Material	Properties	Tensile	Elong.	HDT	Best for	Cost
PA12Nylon 12	ToughStructural	48 MPa	15%	95°C	Enclosures, ducting, snap-fit housings	$$
PA11Nylon 11	ToughImpact	48 MPa	40%	95°C	Ductile, impact-tough parts, snap-fits	$$
PA12-GFglass-filled	RigidWear-resistantHigh-temp	51 MPa	4%	157°C	Stiff, heat-resistant housings	$$
TPU powder	Flexible	9 MPa	220%	—	Lattices, cushioning, flexible production	$$$

Metal (DMLS / SLM)

Metal powder

Fine metal powder fused by laser into fully dense parts. For end-use metal geometry that machining cannot reach.

6 materials

Best for: End-use metal parts, conformal cooling, lightweighting
Accuracy: ±0.1 to 0.2 mm

Material	Properties	Tensile	Elong.	HDT	Best for	Cost
AlSi10Mg	LightweightStructural	430 MPa	6%	—	Lightweight brackets, heat sinks	$$
316L	Chemical-resistantStructural	560 MPa	40%	—	Corrosion-resistant marine and medical	$$
17-4 PHValues after H900 aging	StructuralWear-resistant	1000 MPa	10%	—	High-strength hardware and tooling	$$
Ti-6Al-4V	LightweightBiocompatibleStructural	1000 MPa	10%	—	Aerospace, medical implants	$$$
Inconel 718Values as-built, before age-hardening	High-tempStructural	1100 MPa	20%	—	Hot-section, turbine, exhaust parts	$$$
Cobalt-chrome	Wear-resistantBiocompatibleHigh-temp	1100 MPa	15%	—	Dental, medical, wear surfaces	$$$

Typical values from manufacturer datasheets. Actual results vary by shop, machine, and print settings. Cost is relative, not a quote.

Design rules

How to design for 3D Printing

Design rules span the common processes (FDM, SLS, SLA). Your process shifts the exact numbers; a shop confirms against it.

Design rule	Typical spec	Why
Min wall thickness	0.8 to 1.0 mm (FDM), 0.7 mm (SLS)	Thinner walls print poorly or fail to form.
Min feature size	0.4 to 0.5 mm	Below the nozzle or laser spot size, fine features blur or drop out.
Clearance for fits / moving parts	0.3 to 0.5 mm	Tighter gaps fuse mating parts together.
Hole diameter allowance	add 0.1 to 0.2 mm	Printed holes come out slightly undersized.
Unsupported overhang	<= 45 degrees from vertical	Steeper overhangs need support material that leaves marks.
Min embossed / engraved detail	>= 0.5 mm wide and tall	Finer text or detail does not resolve on the print.

FDM, SLS, and SLA each have their own limits. Tell us the process, or let us match your part to the right one.

Reference

Related reference charts

Free spec + tolerance charts for designing these parts.

3D printing tolerance chart

Secondary operations

Inserts, hardware and finishing

Threads and inserts

Printed holes are cleaned up after the build; heat-set inserts, tapped threads, and pressed hardware are added as a secondary op. Metal DMLS parts are commonly machined on critical faces and bores after printing.

Finishing

Applied after support removal. As-printed ships fastest; bead blast, dyeing, vapor smoothing, and paint are common depending on process.

Finish	Materials	Adds	Can be applied with
As-printed	All	+0 days	Anything
Support removal	FDM, SLA, metal	+0-1 day	Included
Bead blast	SLS, MJF, metal	+1 day	Dye, paint
Dyed (black)	SLS, MJF nylon	+1-2 days	After blast
Vapor smooth	ABS, resin	+1-2 days	Paint
Machined features	Metal DMLS	+2-4 days	Heat treat

SLS and MJF parts come off the machine with a slightly grainy matte surface and are usually bead blasted, then dyed black if color matters. Say up front which faces are cosmetic or critical.

Process comparison

3D printing vs other processes

When a traditional process fits better than printing the part.

Process	Best for	Typical volume	Choose it over 3D Printing when
CNC Machining	Tight tolerance, functional metal and plastic parts	Prototype to production	You need tighter tolerances, a better finish, or full engineering-grade material properties.
Injection Molding	High-volume identical plastic parts	1,000+	You are past a few hundred parts and can amortize a mold for a much lower per-part cost.
Sheet Metal	Flat and bent metal parts	Prototype to production	The part is really bent sheet metal, which is stronger and cheaper.

Get a better quote

Getting a quote that comes back fast

Instead of	Send this
"Print this part"	"PA12 SLS, qty 25, matte black dyed, per STEP"
"Make it strong"	"CF-Nylon FDM, 3 mm walls, 50% infill, load along the X axis"
"Needs to look nice"	"SLA tough resin, bead-blast and prime, ±0.15 mm on the bore"

Tell us the process (or the requirement and let the shop pick), material, quantity, and which faces are cosmetic or load-bearing. That is what sets the price and the machine.

Applications

Industries we serve

Additive shops on OpenSpindle print prototypes, jigs and fixtures, and low-volume end-use parts for demanding industries, including AS9100 and ISO 13485 shops.

Aerospace & defense Medical devices Robotics & automation Automotive Electronics

Consumer products

Industrial / OEM Energy

Need a different process?

Get a quote for these capabilities too.

CNC Machining CNC Turning 5-Axis Machining Sheet Metal & Press Brake EDM & Wire EDM Powder Coating

Designing for this process

What actually changes your quote

Not a definition of 3D printing. The design choices that move your price, strength, and finish.

Pick the process, not just the printer

FDM is cheap and tough, SLA is smooth and detailed, SLS is strong with no supports, metal is end-use. Tell the shop the requirement and it routes to the right one, or spec the process yourself.

Orientation sets strength and finish

FDM parts are weakest between layers, so orient the print with loads running along the layers, not across them. Orientation also decides where support marks and layer lines land.

Wall thickness has a floor

Every process has a minimum printable wall, roughly 0.8 to 1.5 mm. Thinner walls warp or fail to print. Thicken load paths and hollow out bulk to save material and cost.

Design for the support

Overhangs past about 45 degrees need support that leaves marks and adds cleanup. Add fillets and chamfers, or reorient the part, to keep support off surfaces that show.

Questions

Frequently asked questions

It depends on the job. FDM for cheap functional prototypes and rugged parts, SLA or DLP for smooth cosmetic parts and fine detail, SLS or MJF for strong production parts with complex geometry and no supports, and metal DMLS for end-use metal parts. Describe the requirement and shops recommend the process.

Get 3D printing quotes

Upload a model and we'll source quotes from qualified manufacturing partners.

Upload Files & Get Free Quotes

STEP · STL · IGES · DWG · DXF · PDF · and more

Uploads are secure & confidential

No CAD file?