Nylon PA-12 MJF — 3D Printing Specs

// Material Science

PA-12 Mechanical Properties

Data per HP Material Data Sheet (MDS) for PA 12 on HP MJF 5200 series. XY and Z directions reported — near-isotropic due to MJF's thermal agent process.

Tensile Strength (XY)

48

MPa (6,960 psi)

Tensile Strength (Z)

48

MPa — near isotropic

Elongation at Break (XY)

20%

ASTM D638

Elongation at Break (Z)

15%

ASTM D638

Flexural Modulus

1,700

MPa (246 ksi)

Impact Strength (Charpy)

53

kJ/m² notched

Heat Deflection Temp

175

°C @ 0.45 MPa

Density (printed)

1.01

g/cm³

Why MJF is near-isotropic. Unlike FDM or SLA which build layer-by-layer with directional fiber bonds, HP's MJF process uses a fusing agent that heats the full layer cross-section simultaneously. This produces interlocked crystalline boundaries between layers — resulting in Z-direction strength within 5–10% of XY direction.

PA-12 chemical resistance. Resistant to hydrocarbons, greases, oils, fuels, many solvents, and dilute acids/bases. Excellent fatigue resistance for cyclic loading applications. Not recommended for sustained exposure to strong acids, aldehydes, or ketones.

Rated Performance vs. Common 3D Print Materials

Tensile Strength85/100

Impact Resistance90/100

Surface Detail88/100

Chemical Resistance80/100

Isotropy92/100

Geometric Complexity95/100

Key Compliance & Standards

ISO 11600	HP Certified Powder
ASTM D638	Tensile Testing
ASTM D790	Flexural Properties
RoHS Compliant	Yes
UL 94	HB classification

// Machine Envelope

Build Volume & Tolerances

Xeon NC operates HP MJF 5200 printers. Maximum build volume and achievable tolerances shown below. Larger parts may be split and bonded.

// Maximum Build Envelope — HP MJF 5200

380 × 284 × 380

mm

14.96 × 11.18 × 14.96 inches · X × Y × Z axes

X Axis (Width)

380 mm

14.96 in

Y Axis (Depth)

284 mm

11.18 in

Z Axis (Height)

380 mm

14.96 in

Standard Accuracy

± 0.3 mm or ± 0.3%

Whichever is greater. Applied to all linear dimensions. Standard for most functional and structural parts.

Dimension	Tolerance
≤ 100 mm	± 0.30 mm
100 – 200 mm	± 0.30 – 0.60 mm
> 200 mm	± 0.3% of dim

Layer Resolution

Layer Thickness

0.08 mm

Min Feature Size

0.5 mm

Min Wall Thickness

1.0 mm

Min Hole (thru)

1.5 mm

No support structures required. MJF uses unfused powder as its own support material — enabling complex undercuts, channels, and internal geometries with no cleanup.

// Surface Quality

Surface Finishes Available

All parts are bead-blasted as standard. Additional post-processing options below — select only what your application requires.

⬜

Natural Gray (As-Built)

Ra ≈ 8–12 µm

Bead-blasted uniform gray surface. Slight visible layer lines on steep vertical faces. Best value — included in base price. Functional for most structural applications.

⬛

Dyed Black

Ra ≈ 8–12 µm · Deep penetration

Water-based dye penetrates 0.5–1 mm into the surface — not just a surface coat. Uniform flat black. UV-stable for indoor use. Does not change dimensional accuracy.

✦

Vapor Smoothed

Ra ≤ 1.5 µm · Near gloss

Chemical vapor smoothing reflows the outer surface to near-injection-molded quality. Improved watertightness, reduced friction, and enhanced aesthetics. Slight dimensional change (~0.1 mm per surface).

🎨

Painted (RAL/Pantone)

Ra ≈ 3–6 µm after primer coat

Primer coat followed by color topcoat. Supports any RAL or Pantone color. Typical thickness +0.1–0.2 mm per side. Ideal for cosmetic and marketing parts.

⚡

Electroless Metal Plated

Copper · Nickel · Chrome

Electroless copper or nickel plating over primed PA-12. Creates a conductive, metallic-look surface. Used for EMI shielding, decorative metallics, and conductive traces.

💧

Watertight Sealing

Epoxy / urethane internal coat

Internal channel and surface coating for pressure-tested fluid passages, tanks, and manifolds. Required for any liquid-contact or low-pressure pneumatic application.

// Engineering Guidelines

MJF Design Guidelines

Key design rules for HP MJF PA-12 to achieve optimal part quality, accuracy, and printability. Refer to infographics for visual reference.

📐 Minimum Thickness & Thin Walls

Min Supported Wall1.0 mm

Min Unsupported Wall1.5 mm

Rec. for Strength2.0 mm+

Min Embossed Detail0.5 mm high

Min Engraved Detail0.5 mm deep / wide

⭕ Holes, Channels, Gaps & Undercuts

Min Through Hole Ø1.5 mm

Min Blind Hole Ø2.0 mm

Min Slot / Channel Width1.5 mm

Min Escape Hole (hollow)3.5 mm Ø

Undercut CapabilitySupported (no extra cost)

🔲 Massive Parts & Voids

Solid Part Shell Rec.Hollow if > 20 mm wall

Min Hollow Shell Wall3.0 mm

Powder Escape Hole≥ 2 holes × ≥ 3.5 mm Ø

Max Solid Section (warping risk)> 50 mm → hollow

🔤 Text, Logos & Fine Features

Min Embossed Text Height1.0 mm

Min Embossed Text Depth0.5 mm

Rec. Font Width (stroke)≥ 0.8 mm

Logo/Image Min Size5 × 5 mm

Best Orientation for TextUpward facing (XY plane)

// Post-Processing

Available Post-Processing

All post-processing is performed in-house or by qualified partners. Lead times are additive to base print time.

💨

Bead Blasting

Removes excess powder and creates uniform matte gray surface. Included with every part at no extra charge.

🖤

Dyeing

Black dye or custom colors. Penetrates the surface for durability. Does not affect tolerances.

✨

Vapor Smoothing

Chemical vapor reflow — produces Ra ≤1.5 µm near-gloss surface. Improves watertightness and aesthetics.

🎨

Painting

Primer + topcoat in RAL or Pantone colors. Recommended over vapor-smoothed surface for best adhesion.

⚡

Metal Plating

Electroless copper, nickel, or chrome. Creates conductive surfaces for EMI/RFI shielding or decorative metallic finishes.

🔩

Threaded Inserts

Heat-set brass inserts pressed into designed bosses. M2–M8 inserts available. Recommended over direct threading.

💧

Watertight Sealing

Internal epoxy or urethane coating for fluid passages, tanks, and manifolds. Tested to 2 bar (29 psi).

📐

CNC Post-Machining

Critical bores, threads, and mating surfaces post-machined to ±0.05 mm. Ideal for bearing seats and precision fits.

// Common Questions

PA-12 MJF FAQ

Engineering and ordering questions answered.

How does MJF compare to SLS Nylon?

+

HP MJF and SLS both use powder-bed fusion with nylon, but MJF uses a fusing agent applied by inkjet printheads rather than a laser. MJF is generally faster (full-width pass per layer), produces more consistent surface finish, and achieves better isotropy due to the uniform thermal profile. Mechanical properties are very similar — MJF PA-12 is slightly superior in elongation at break. Both require no supports and can print complex internal geometries.

Is PA-12 MJF food safe?

+

HP PA-12 MJF material meets the chemical requirements under FDA 21 CFR and EU 10/2011 for food contact. However, the porous as-built surface can harbor bacteria, so bare PA-12 should not be used for repeated direct food contact without a food-safe sealing coat (vapor smoothing + food-grade epoxy). Always verify compliance for your specific application with a food safety engineer.

What is the best finish for snap-fit or living hinge features?

+

Natural gray as-built is recommended for snap-fit and living hinge features — vapor smoothing or other coatings can slightly alter surface characteristics and may reduce fatigue life in high-cycle designs. Keep hinge thickness at 0.7–1.0 mm and ensure the flex geometry is oriented in the XY plane for best elongation properties. Design your hinge to stay within the elastic zone (strain < 5% for PA-12).

Can I thread directly into PA-12 MJF printed parts?

+

Yes — PA-12 can be tapped after printing. For M3 and larger, design a boss with proper pre-drill hole size and tap using a hand tap or CNC. For repeated assembly/disassembly, heat-set brass threaded inserts (available as a post-processing option) are strongly recommended — they provide much longer thread life and higher torque resistance than tapped nylon.

What file formats do you need for 3D printing?

+

We accept STL, STEP (.stp/.step), OBJ, and native SolidWorks (.sldprt) files. STL is preferred for 3D printing — ensure it is watertight (manifold) with no inverted normals before submitting. STEP files are useful when you need clean CAD geometry for post-machining reference. Minimum feature size on your model should be ≥ 0.5 mm — smaller features may not print reliably.

NylonPA-12MJF

Nylon
PA-12
MJF