What is the difference between SLS Nylon 12 and FDM Nylon?

SLS Nylon 12 offers superior dimensional accuracy, isotropic Z-axis strength, support-free design freedom, and smooth matte surface finishes. FDM Nylon exhibits anisotropic weakness between layers, warping during print bed cooling, and requires removable support structures.

SLS Powder · Industrial 3D Printing

Nylon 12 Powder (SLS)

Q: What is Nylon 12 SLS 3D printing?

Nylon 12 SLS 3D printing is an industrial powder-bed fusion process (Selective Laser Sintering) that uses a high-power laser to fuse polyamide 12 particles layer by layer. It produces highly durable, isotropic thermoplastic parts without requiring support structures.

Q: Is SLS Nylon 12 mechanical strength isotropic?

Yes. Unlike FDM 3D printing which suffers from weak Z-axis layer adhesion, SLS Nylon 12 produces near-isotropic mechanical properties. Tensile strength and impact resistance remain consistent across X, Y, and Z axes.

Q: How strong is Formlabs Nylon 12 Powder?

Formlabs Nylon 12 Powder has a tensile strength of 50 MPa, a flexural modulus of 1.8 GPa, and an elongation at break of 18%. It combines high tensile performance with ductility, making it ideal for living hinges, snap fits, and structural enclosures.

Q: Do SLS Nylon 12 parts require support structures?

No. During the SLS printing process, un-sintered powder acts as a natural support medium around the part. This allows engineers to design complex geometries, internal fluid channels, undercuts, and nested assemblies without support removal artifacts.

The gold standard for Selective Laser Sintering. Nylon 12 combines high tensile strength, near-isotropic durability, and support-free complex geometry for functional prototypes and end-use manufacturing.

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50 MPa

Tensile Strength

High load capacity

1.8 GPa

Flexural Modulus

Stiff & deformation resistant

18%

Elongation at Break

High ductility & snap-fit capable

171 °C

Heat Deflection

@ 0.45 MPa thermal rating

Available in grey & white

Real Nylon 12 SLS Parts

Actual Formlabs Fuse Series prints in Nylon 12 Powder, not renders.

Power-tool housing 3D printed in Formlabs Nylon 12 Powder on an SLS printer, shown in the standard matte gray finish — Power-tool housing, printed as a single part in the standard matte gray finish.

Two halves of a Nylon 12 SLS part showing internal ribbing and nested lattice geometry printed without support structures — Internal ribbing and nested lattice geometry, printed support-free in one build.

Technician hand-brushing loose powder off a Nylon 12 SLS part during standard media-blast post-processing — Standard finish: hand-brushed and media-blasted to remove all loose, un-sintered powder.

Summary & Key Takeaways

Isotropic Performance: Laser-sintered particles deliver uniform strength across X, Y, and Z axes.
Zero Support Structures: Un-sintered powder supports part overhangs, enabling complex internal channels.
End-Use Durability: Resistant to wear, fatigue, hydrocarbons, and environmental moisture.
Precision Tolerances: Achieves ±0.3% dimensional accuracy (lower limit ±0.15 mm) on Formlabs Fuse systems.

Compare Nylon 12 SLS to Other 3D Printing Materials

A quick, scannable comparison against alternative 3D printing materials and processes. All values are shown at once; use the buttons to focus on one comparison at a time.

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Tensile strength, flexural modulus, layer strength, and support requirements for SLS Nylon 12 versus FDM Nylon, SLA Tough 2000, and glass-filled SLS Nylon 12 GF.
Property	SLS Nylon 12	FDM Nylon	SLA Tough 2000	Nylon 12 GF
Tensile strength	50 MPa	42 MPa	46 MPa	52 MPa
Flexural modulus	1.8 GPa	1.2 GPa	2.2 GPa	3.5 GPa
Z-axis (layer) strength	Isotropic, matches XY	Weak, common failure point	Isotropic, cured as one volume	Isotropic, matches XY
Support structures	None required	Removable supports for overhangs	Removable supports for overhangs	None required

Why Choose SLS Nylon 12?

Selective Laser Sintering with Nylon 12 powder offers core engineering advantages over traditional prototyping.

Isotropic Mechanical Properties

Laser sintering welds powder particles uniformly. Unlike FDM printing where Z-axis layers break easily, SLS Nylon 12 parts exhibit nearly equal tensile and flexural strength in all directions.

Support-Free Geometric Freedom

Because un-sintered powder cradles the part during printing, you can design internal fluid conduits, nested assemblies, and organic lattice structures without worrying about support removal.

Environmental & Chemical Resistance

Nylon 12 exhibits minimal water absorption compared to Nylon 6. It resists alkalis, hydrocarbons, fuels, and weak acids, making it suitable for under-the-hood automotive and industrial components.

Nylon 12 SLS Color Options: Grey vs. White

Form Now prints Nylon 12 SLS in two colors. Both share the same laser-sintering process and biocompatibility; the difference is finish appearance and a small trade-off in toughness.

Standard Grey

The default color for Nylon 12 SLS parts — a matte, lightly speckled charcoal-grey finish typical of laser-sintered nylon. It offers the best impact resistance and ductility of the two colors, making it the go-to choice for functional prototypes, brackets, enclosures, and end-use mechanical parts.

32 J/m

Notched Izod (impact)

11%

Elongation at break

White

A bright white finish that more closely resembles the look of MJF-printed nylon than traditional SLS grey, with higher contrast for fine detail. White parts can also be dyed after printing to match a target color. The trade-off is somewhat lower impact strength and ductility than standard grey.

28 J/m

Notched Izod (impact)

Elongation at break

Color does not affect stiffness or heat performance — both colors share a tensile modulus around 1.9–1.95 GPa and a heat deflection temperature of 87°C. Color is selected during part configuration after upload.

Nylon 12 SLS Design Rules (DFM) at a Glance

Formlabs' own Fuse 1 design specifications for parts printed in Nylon 12 Powder, with the reference diagrams below the table. Check your CAD feature dimensions against these limits before uploading your file.

Min. wall thickness (vertical · horizontal)	0.8 mm for both (same minimum whether the wall is supported or unsupported)
Min. pin/wire diameter	0.8 mm
Min. hole diameter	1.0 mm
Min. drain/escape hole (2 per powder-trapping cavity)	3.5 mm
Clearance, mating features separated after printing	0.2 mm (< 20 mm²) · 0.4 mm (> 20 mm²)
Clearance, mating features printed pre-assembled	0.3 mm (< 20 mm²) · 0.6 mm (> 20 mm²)
Clearance between unrelated parts in a build	1.0 mm min · 5.0 mm recommended
Min. embossed detail (raised text/logos)	0.15 mm deep, horizontal face · 0.35 mm deep, vertical face (4.5 mm min. text height)
Min. engraved detail (recessed text/logos)	0.1 mm deep, horizontal face · 0.15 mm deep, vertical face (3.0 mm min. text height)
Max. single-part build size	330 × 330 × 565 mm

Diagram of a Nylon 12 SLS part showing minimum vertical and horizontal wall thickness — **Wall thickness**Design vertical and horizontal walls to 0.8 mm or more to reliably avoid warping or detaching mid-print.

Diagram of a Nylon 12 SLS part showing minimum pin and wire diameter — **Pins & wires**Thin pins and wires can deform or snap while printing or during depowdering.

Diagram of a Nylon 12 SLS part showing minimum hole diameter — **Hole diameter**Holes under 1.0 mm risk closing up as the surrounding powder sinters.

Diagram of a Nylon 12 SLS part showing minimum drain hole diameter for an enclosed cavity — **Drain holes**Enclosed cavities need at least two 3.5 mm+ holes, or they stay packed with loose powder.

Diagram of two Nylon 12 SLS parts showing minimum assembly clearance for parts separated after printing — **Clearance, separated after printing**Leave 0.2-0.4 mm between mating features you'll pull apart by hand, like gears or hinges.

Diagram of a Nylon 12 SLS part showing minimum clearance for an assembly printed pre-interlocked — **Clearance, printed pre-assembled**Interlocked features need 0.3-0.6 mm or the laser can fuse them together.

Diagram showing minimum embossed text depth and width on horizontal versus vertical faces — **Embossed detail**Raised text and logos need more depth on vertical faces (B) than horizontal ones (A).

Diagram showing minimum engraved text depth and width on horizontal versus vertical faces — **Engraved detail**Recessed detail needs less depth than embossed, but the same face-orientation difference applies.

Source: Formlabs' Design specifications for 3D models: Fuse 1, adapted to hold walls to a higher minimum than Formlabs' published figures. These are general guidelines; thicker cross-sections, hole depth, and part geometry can shift the safe minimums for a specific design. Maximum build size reflects our largest-format SLS printer; actual build size depends on which machine your order routes to.

Frequently Asked Questions

Everything you need to know about designing, ordering, and using Nylon 12 SLS parts on Form Now.

What is Nylon 12 SLS 3D printing?

Nylon 12 SLS (Selective Laser Sintering) 3D printing is an additive manufacturing process that uses a laser to sinter powdered nylon (polyamide 12) layer by layer into solid thermoplastic parts. It delivers production-grade strength, isotropic properties, and support-free geometric capability.

Is SLS Nylon 12 mechanical strength isotropic?

Yes. SLS laser sintering creates strong intermolecular bonds across X, Y, and Z build axes. Unlike FDM 3D printing where Z-axis layer separation is a common failure point, SLS Nylon 12 exhibits near-isotropic mechanical properties.

How strong is Formlabs Nylon 12 Powder?

Formlabs Nylon 12 Powder features a tensile strength of 50 MPa, flexural modulus of 1.8 GPa, and 18% elongation at break. This combination provides both structural stiffness and high fatigue resistance.

Do SLS Nylon 12 parts require support structures?

No. Un-sintered powder surrounds and supports the part during printing. This eliminates the need for support structures, allowing for intricate internal cavities, steep overhangs, and pre-assembled mechanical hinges.

What finish do Nylon 12 SLS parts arrive in?

Form Now SLS Nylon 12 parts ship in the standard finish: hand-brushed and media-blasted to remove all loose, un-sintered powder, leaving a clean, uniform matte gray surface. Any additional finish options for a given order are shown during part configuration at checkout.

What color options are available for Nylon 12 SLS?

Form Now offers Nylon 12 SLS in standard grey at no added cost, and white for a small additional cost. Grey has the higher impact strength and elongation at break of the two; white offers a brighter, higher-contrast finish closer to MJF parts and can be dyed after printing. Both share the same tensile modulus and heat deflection temperature.

What are the minimum wall thickness and hole size design rules for Nylon 12 SLS?

Per Formlabs' Fuse 1 design specifications, we recommend a minimum wall thickness of 0.8 mm for both vertical and horizontal walls, whether the wall is supported or unsupported, to reliably avoid warping or detaching during the print. Holes should be at least 1.0 mm in diameter, and cavities that trap powder need at least two 3.5 mm drain holes. Maximum single-part build size is 330 x 330 x 565 mm.

What is the smallest text or logo I can emboss or engrave on a Nylon 12 SLS part?

Raised (embossed) text needs at least 0.15 mm depth on a horizontal face or 0.35 mm on a vertical face, with a minimum text height of 4.5 mm. Recessed (engraved) text needs less depth: 0.1 mm on a horizontal face or 0.15 mm on a vertical face, with a minimum text height of 3.0 mm. Use a bold font for small logos or labels so fine detail does not get lost during sintering.