Loading page
Network line, now onboarding principals
Multi Jet Fusion
Multi Jet Fusion (MJF) is a powder bed 3D printing process. A recoater spreads a thin layer of nylon powder, an inkjet head prints a fusing agent where the part is and a detailing agent at its edges, and infrared lamps fuse the inked areas. Layers are about 0.003 in (80 µm). Parts need no supports, hold about ±0.3%, and ship in 3–7 days.
A method under additive manufacturing.
How does Multi Jet Fusion work?
The schematic plays while it is on screen. Pick a phase to hold it there.
- 1
Nest the build
Parts are packed in 3D inside the build volume. Density of the nest drives the cost per part.
- 2
Spread a layer
A recoater sweeps a layer of powder about 0.003 in (80 µm) thick across the heated bed.
- 3
Jet the agents
An inkjet carriage prints fusing agent on the part's cross-section and detailing agent around its edges to keep them sharp.
- 4
Fuse
Infrared lamps pass over the bed. Inked areas absorb the heat and fuse; bare powder stays loose and supports the part.
- 5
Lower and repeat
The platform drops one layer and the cycle repeats, often for thousands of layers.
- 6
Cool, unpack, finish
The build unit cools for hours, then parts are dug out, bead blasted and optionally dyed, vapor smoothed or machined.
What can Multi Jet Fusion hold?
Typical ranges across principals. Your drawing, material and quantity set the real numbers in the quote.
| Tolerance | ±0.3%, minimum ±0.012 in (±0.3 mm) |
|---|---|
| Layer thickness | About 0.003 in (80 µm) |
| Build volume | About 15 × 11.2 × 15 in (380 × 284 × 380 mm) |
| Minimum wall | 0.020 in (0.5 mm) possible; 0.040 in (1 mm) recommended |
| Materials | PA12, PA11, PA12 glass-bead, TPU, PP |
| Color | Gray as printed; dyed black typical |
| Lead time | 3–7 days typical |
When is Multi Jet Fusion the right call?
Best for
- Functional PA12 and PA11 nylon parts: housings, brackets, clips, ducts
- Batches of 10–5,000 parts nested in one build
- Complex internal channels and assemblies with no support removal
- Bridge production before a mold is ready
Pick something else when
- Smooth cosmetic prototypes: SLA
- Over about 5,000 parts a year of one design: injection molding is cheaper per part
- Metal parts or parts above about 200 °F (93 °C) service: CNC machining or metal processes
How does Multi Jet Fusion compare with the alternatives?
Typical values. Pick an alternative to see where each one wins.
Multi Jet Fusion compared with
Multi Jet FusionSLS
- Precisionlooser → tighter
- Volume it pays atone-offs → millions
- Upfront toolingnone → heavy
- Shape freedomnarrow → wide
Multi Jet Fusion · pick it when
Functional nylon parts in batches, with no supports and even properties.
SLS · pick it when
Nylon parts in a wider range of powders, or colors other than gray and black.
About SLSMethodTypical toleranceEconomic volumeToolingLead time
- Multi Jet Fusionthis pageTypical tolerance±0.3%, minimum ±0.012 in (±0.3 mm)Economic volume1–5,000 partsToolingNoneLead time3–7 days
- Typical tolerance±0.3%, minimum ±0.012 in (±0.3 mm)Economic volume1–1,000 partsToolingNoneLead time3–7 days
- Typical toleranceAbout ±0.005 in (±0.13 mm) over the first inchEconomic volume1–100 partsToolingNoneLead time2–5 days
- Typical toleranceAbout ±0.010 in (±0.25 mm)Economic volume1–50 partsToolingNoneLead time2–5 days
- Typical toleranceAbout ±0.010 in (±0.25 mm)Economic volume10–200 partsToolingSilicone mold $500–$2,500Lead time1–3 weeks
Which design rules keep Multi Jet Fusion affordable?
Rules of thumb principals apply at DFM review. Each one has a reason.
RuleTargetWhy
- Wall thickness
- ≥ 0.040 in (1 mm)
- Thinner walls print but warp and break during cleaning.
- Clearance between moving parts
- ≥ 0.020 in (0.5 mm)
- Less than this and neighboring features fuse together.
- Escape holes
- ≥ 0.200 in (5 mm) in hollow parts
- Unfused powder has to come out. Two holes clean faster than one.
- Large flat areas
- Add ribs or break them up
- Big flat sections warp as they cool.
- Hardware
- Heat-set inserts for threads
- Printed threads under M5 wear quickly. Inserts hold.
What drives the cost of Multi Jet Fusion?
In order of impact.
- 1
Part volume and bounding box
Priced by material volume and how much build space the part takes. Hollowing and nesting cut cost.
- 2
Nest density
A full build spreads machine time and cooling over more parts.
- 3
Post-processing
Dyeing, vapor smoothing, painting and inserts add per-part labor.
- 4
Material
PA11 and TPU cost more than PA12.
Budgetary estimate for a printed nylon enclosure, from the same estimator as the part builder. Change a size, the quantity or the material and the price updates.
Housing · 3D printing
Order total $938
- Tooling
- None
- no hard tooling
- Piece price
- $37.50
- before setup + tooling
- Lead time
- 3–7 days
- to first production
Size
Drag a row to adjust · click to type
Length140140 mm
Width90.090.0 mm
Wall2.202.20 mm
Quantity
Price per part falls as volume rises
Exact quantity2525 pcs
Material
Design checks pass
Open in builderBudgetary estimate for a representative part. Firm quotes come from principals after drawing review.
Multi Jet Fusion questions
How is MJF different from SLS?
Both fuse nylon powder without supports. SLS draws each layer with a laser; MJF prints agents and fuses the whole layer with infrared heat, which is faster for full builds. MJF parts are gray and usually dyed black; SLS offers more powders and colors.
How strong are MJF parts?
PA12 MJF parts have tensile strength around 48 MPa (7,000 psi) in the XY plane, close to molded nylon 12, with lower elongation. Properties are close to even in every direction.
When does injection molding beat MJF?
It depends on part size, but the crossover is often a few hundred to a few thousand parts. A small part may be cheaper molded at 500 pieces; a large, complex part may stay printed to 5,000.
Can MJF parts be smoothed?
Yes. Bead blasting is standard. Vapor smoothing seals the surface to a near-molded finish, and parts can be dyed, painted or coated.
Quote Multi Jet Fusion with a rep.
Send a STEP file and drawing. A rep routes the RFQ to principals that run this method every day, and brings back firm quotes.