Multi Jet Fusion (MJF)
MJF 3D printing for functional nylon parts: 380 x 284 x 380 mm build envelope, ±(0.3 mm + 0.002 mm/mm) tolerance, 0.08 mm resolution, lead time as fast as 3 days, PA 12 and PP.
Last updated: 2026-10-29
Multi Jet Fusion builds functional thermoplastic parts by jetting fusing and detailing agents across a bed of polymer powder, producing isotropic nylon components that behave like end-use plastic parts — not prototypes. Resolution is 0.08 mm with tolerance of ±(0.3 mm + 0.002 mm/mm), and bridge-production runs of 10–1,000 units are the natural territory.
The build envelope reaches 380 x 284 x 380 mm (15 x 11.2 x 15 in). Design rules: 1 mm minimum wall for consistent measurement and mechanical properties, and 0.2 mm minimum gaps between mating parts — 0.3 mm recommended for a reliable fit. Lead time is as fast as 3 days in PA 12, glass-bead-filled PA 12 or polypropylene.
Specifications
| Specification | Multi Jet Fusion (MJF) |
|---|---|
| Tolerance | ±(0.3 mm + 0.002 mm/mm); resolution 0.08 mm |
| Max Part Size | 380 x 284 x 380 mm (15 x 11.2 x 15 in) |
| Lead Time | As fast as 3 days |
Materials
Surface Finishes
Multi Jet Fusion 3D printing builds functional nylon parts layer by layer with a 0.08 mm resolution, bridging prototyping and production runs of 10–1,000 units. Build envelopes reach 380 x 284 x 380 mm (15 x 11.2 x 15 in); tolerance is ±(0.3 mm + 0.002 mm/mm) with a 1 mm minimum wall for consistent mechanical properties and 0.2 mm minimum gaps between mating parts (0.3 mm recommended). Lead time is as fast as 3 days in PA 12, glass-bead-filled PA 12 or polypropylene.
Values above are the collected catalog specification envelope for this product family. Tolerances and lead times at the demanding end of a range are confirmed for the specific geometry, material and batch at quotation.
Applications & Selection Points
Bridge production 10–1,000 units
The volume band where injection tooling has not amortized but one-offs are too slow: pilot series, replacement parts, market-testing builds. MJF pricing scales with build density — nesting parts across the 380 x 284 x 380 mm envelope drops unit cost sharply.
Functional nylon prototypes
Snap-fits, living hinges, clips and housings that must survive assembly and use. PA 12 behaves like a production thermoplastic, so test results transfer to later molding decisions; glass-bead PA 12 adds stiffness where the part sees load.
Lattice and complex internal geometry
Powder-bed printing needs no support removal inside the part, so internal channels, lattice infill and shrouded features print cleanly. Design the 0.3 mm mating gaps and 1 mm walls into the model — post-machining nylon is possible but rarely the cheap route.
When MJF is the wrong printer
MJF parts are thermoplastics: extreme heat, or metal-grade stiffness, route to metal 3D printing or machining. Very large single parts beyond the envelope split or print by another process — check the envelope against the part early.
Frequently Asked Questions
MJF vs SLS — both are nylon powder bed processes, which one?
Both print functional PA 12. MJF generally wins on surface detail, isotropy and cost at 10–1,000-unit volumes because its fusing agent controls energy precisely; SLS offers a wider material menu on some platforms. For a first functional nylon part at bridge-production volume, MJF is the default; material specialty needs may flip it.
What tolerance and wall thickness does MJF hold?
Tolerance is ±(0.3 mm + 0.002 mm/mm) with 0.08 mm resolution. Walls below 1 mm lose consistent measurement and mechanical properties — design 1 mm minimum, and 0.2 mm minimum gaps between mating parts (0.3 mm recommended). Dimensions that must sit tighter than the tolerance band should be machined after printing.
What does an MJF quote need?
A 3D model (STEP or STL), material choice (PA 12, glass-bead PA 12, or polypropylene), quantity and any dyeing or finishing requirement. Quantity is the biggest cost lever — parts that fill the build envelope together print cheaper per unit, so quote your true batch, not a sample of one.
Ordering & Documentation
Documents
A watertight 3D model (STEP preferred; STL accepted) with the 1 mm wall and 0.2–0.3 mm mating gaps designed in. Note critical dimensions that need post-print machining so they are datumed for it.
Quotation
Pricing inputs: model, material, quantity and finish (natural, dyed black, or vibratory). Lead time is as fast as 3 days on standard service; add finishing time where dyeing applies.
Sample & Supply
A single print validates fit before the batch — cheap insurance at bridge-production quantities. Repeat batches reuse the same model file; revision changes are a file version, not tooling.
Storage & Shipping
Natural PA 12 ages under UV and absorbs moisture — bag parts in polyethylene for storage and say so if parts will sit before use. Printed parts are light; shipping cost is volume, not weight.