Materials · PA12 nylon

Vapor smoothing for PA12 nylon parts.

PA12 vapor smoothing reflows the grainy, porous surface of a 3D printed nylon 12 part into a smoother, sealed skin, with very little change to its dimensions. PostPro systems smooth PA12 from MJF · SLS · SAF · HSS1, with PostPro Pure on every system and FA326 on the SF50 and SF100.

Test your parts, free Get a price

No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks2

Dimensional change
≤ 0.4%32024
PA12 · voxeljet HSS
Elongation at break
+38.1% (XY)32024
PA12 · voxeljet HSS
Burst pressure
up to +7%42024
PA2200 · SLS

Why smooth PA12

A strong nylon with an open surface.

PA12 is a staple of MJF, SLS, SAF and HSS printing, and its parts come off the printer strong but grainy and porous. That surface is what holds dirt, takes up water and makes a part feel printed.

  1. Sealed against fluids

    Reflowing the surface closes the pores between powder grains, so ducts, housings and fluid parts take up less water and dirt.

  2. Stronger in tension

    A smoother surface has fewer notches for a crack to start from. In AMT’s HSS PA12 test, elongation at break rose +38.1% (XY)32024.

  3. Dimensions held

    The surface skin reflows, not the whole part: dimensional change was ≤ 0.4%32024 on HSS PA12 and ≤ 0.4%42024 on SLS PA2200.

  4. A finished look and feel

    Vapor-smoothed PA12 comes out darker, glossier and easier to clean, closer to a molded part.

Published results

What vapor smoothing measured on PA12.

Each result names the PA12 grade and process it was measured on. Results depend on material, printer and recipe.

  • Dimensions

    ≤ 0.4%32024

    Dimensional change PA12 · voxeljet HSS

  • Dimensions

    ≤ 0.4%42024

    Dimensional change PA2200 · SLS

  • Strength

    +38.1% (XY)32024

    Elongation at break PA12 · voxeljet HSS

  • Sealing

    up to +7%42024

    Burst pressure PA2200 · SLS

  • Surface

    Reduced surface porosity on UL94 V-0 flame-retardant parts5

    Case study HP 3D HR PA 12 FR · HP MJF

  • Skin contact

    No cytotoxic effects and no loss of strength6

    Cytotoxicity test, with PostPro Pure HP 3D HR PA 12 · HP MJF · PostPro Pure

voxeljet HSS PA12 whitepaper SLS PA2200 whitepaper

Agents and systems

Which agent, which machine.

PA12 runs with PostPro Pure or FA326, by process. Every PostPro vapor smoothing system lists PA12.

PA12 by printing process and finishing agent
ProcessMaterialPostPro PureFA326FA9202
MJFPA 127ListedListedNot listed
MJFPA 12 Filled7ListedListedNot listed
SLSPA 127ListedListedNot listed
SLSPA 12 Filled7ListedListedNot listed
SAFPA 121,8,9ListedListedNot listed
HSSPA 11, PA 121ListedNot listedNot listed

Listed by AMT— Not listedPostPro Pure runs in every PostPro system; FA326 on the SF50 and SF100; FA9202 for polypropylene.

Material lists as published on each PostPro product page.10

In production

PA12 parts in service.

Published case studies on vapor-smoothed PA12 parts, each linked to the full story.

  • ProtolabsHP MJF · PA12 FR

    Flame-retardant parts

    Flame-retardant parts with improved surface quality and UL94 V-0 compliance5

  • ABConceptHP MJF · PA12

    Rally car parts

    100+ parts through 2,450+ km of the Rallye du Maroc11

  • NordenHP MJF

    Production machinery

    A single part with internal vacuum channels replaced a multi-component, machined assembly12

Questions

PA12 vapor smoothing: questions.

Short answers from AMT’s published tests and material lists. Anything else, ask an engineer.

Does vapor smoothing work on PA12?

Yes. PA12 from MJF · SLS · SAF · HSS1 is on AMT’s material lists, with PostPro Pure on every PostPro system and FA326 on the SF50 and SF100.

How much does PA12 change dimensionally?

Very little. AMT’s published tests measured ≤ 0.4%32024 on voxeljet HSS PA12 and ≤ 0.4%42024 on SLS PA2200.

Is vapor-smoothed PA12 watertight?

Vapor smoothing seals the surface pores, which keeps water out of the material. In AMT’s SLS PA2200 test, burst pressure rose up to +7%42024. Whether a finished part holds pressure also depends on its design and wall thickness.

Can filled PA12 be vapor smoothed?

Yes, filled PA12 grades from MJF and SLS are listed with PostPro Pure and FA326.7 Send a sample of your grade to confirm the finish.

Which PostPro system should I use for PA12?

All four list PA12: the desktop SFX and SF2X for R&D and low volumes, the SF50 and SF100 for production. The benchmark and the configurator help you choose.

Next step

See the price. Run the numbers. Hold the part.

List prices are public and the cost-per-part math is yours to check, with no email needed for either. The free benchmark puts your own parts, vapor smoothed, in your hands.

  1. 01Quote

    Build your quote

    Pick a system and its options and get an itemized total on screen, from AMT’s published list prices.

    Build your quote

  2. 02ROI

    Calculate your ROI

    Compare your cost per part with manual finishing, using your own labor rate and volumes. Every assumption is editable.

    Calculate ROI

  3. 03Benchmark

    Test your parts, free

    Ship us your parts with a prepaid label. We vapor smooth them and send them back with before-and-after photos and a benchmark report.

    Test your parts, free

    No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks2

Prices: AMT list prices, excluding tax and shipping; confirmed in your formal quote.

Not sure which system? Help me choose