--- title: "PA12 Vapor Smoothing: Nylon 12 Results | AMT PostPro" description: "PA12 vapor smoothing results from AMT tests: dimensional change, elongation, burst pressure and sealing on MJF, SLS and HSS nylon 12 parts." canonical: https://amtechnologies.com/materials/pa12/ updated: 2026-10-07 type: material --- 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 · HSS[1], with PostPro Pure on every system and FA326 on the SF50 and SF100. [Test your parts, free](https://benchmarking.amtechnologies.com/submit?utm_source=amtechnologies.com&utm_medium=material-page&utm_campaign=site-2026&utm_content=pa12-pa12-hero) [Get a price](https://amtechnologies.com/configurator/) No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[2] Material - **Dimensional change**: ≤ 0.4%[3] - PA12 · voxeljet HSS - **Elongation at break**: +38.1% (XY)[3] - PA12 · voxeljet HSS - **Burst pressure**: up to +7%[4] - 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)[3]. 3. ### Dimensions held The surface skin reflows, not the whole part: dimensional change was ≤ 0.4%[3] on HSS PA12 and ≤ 0.4%[4] 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%[3] Dimensional change PA12 · voxeljet HSS - Dimensions ≤ 0.4%[4] Dimensional change PA2200 · SLS - Strength +38.1% (XY)[3] Elongation at break PA12 · voxeljet HSS - Sealing up to +7%[4] Burst pressure PA2200 · SLS - Surface Reduced surface porosity on UL94 V-0 flame-retardant parts[5] Case study HP 3D HR PA 12 FR · HP MJF - Skin contact No cytotoxic effects and no loss of strength[6] Cytotoxicity test, with PostPro Pure HP 3D HR PA 12 · HP MJF · PostPro Pure [voxeljet HSS PA12 whitepaper](https://amtechnologies.com/resources/whitepapers/vapor-smoothing-voxeljets-hss-pa12-with-amt-postpro/) [SLS PA2200 whitepaper](https://amtechnologies.com/resources/whitepapers/performance-improvements-of-vapour-smoothed-sls-pa2200-parts/) 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** | Process | Material | PostPro Pure | FA326 | FA9202 | | --- | --- | --- | --- | --- | | MJF | PA 12[7] | Listed | Listed | Not listed | | MJF | PA 12 Filled[7] | Listed | Listed | Not listed | | SLS | PA 12[7] | Listed | Listed | Not listed | | SLS | PA 12 Filled[7] | Listed | Listed | Not listed | | SAF | PA 12[1,8,9] | Listed | Listed | Not listed | | HSS | PA 11, PA 12[1] | Listed | Not listed | Not listed | - [SFX Desktop PA12 listed](https://amtechnologies.com/products/vapor-smoothing/postpro-sfx-desktop-vapor-smoothing-system/) - [SF2X Desktop, double chamber PA12 listed](https://amtechnologies.com/products/vapor-smoothing/postpro-sf2x/) - [SF50 Production PA12 listed](https://amtechnologies.com/products/vapor-smoothing/postpro-sf50/) - [SF100 High volume PA12 listed](https://amtechnologies.com/products/vapor-smoothing/postpro-sf100/) 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. - Protolabs HP MJF · PA12 FR ### [Flame-retardant parts](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/) Flame-retardant parts with improved surface quality and UL94 V-0 compliance[5] - ABConcept HP MJF · PA12 ### [Rally car parts](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/) 100+ parts through 2,450+ km of the Rallye du Maroc[11] - Norden HP MJF ### [Production machinery](https://amtechnologies.com/resources/case-studies/vapor-smoothing-for-production-machinery/) A single part with internal vacuum channels replaced a multi-component, machined assembly[12] Questions ## PA12 vapor smoothing: questions. Short answers from AMT’s published tests and material lists. Anything else, [ask an engineer](https://share.hsforms.com/1lOH82JpuRdSM-4wJ1ZeYlw45o6d?website_source=Vapor+Smoothing&utm_source=amtechnologies.com&utm_medium=material-page&utm_campaign=site-2026&utm_content=pa12-talk). ### Does vapor smoothing work on PA12? Yes. PA12 from MJF · SLS · SAF · HSS[1] 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%[3] on voxeljet HSS PA12 and ≤ 0.4%[4] 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%[4]. 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. 01 Quote ### 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](https://amtechnologies.com/quote/) 2. 02 ROI ### Calculate your ROI Compare your cost per part with manual finishing, using your own labor rate and volumes. Every assumption is editable. [Calculate ROI](https://amtechnologies.com/roi/) 3. 03 Benchmark ### 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](https://benchmarking.amtechnologies.com/submit?utm_source=amtechnologies.com&utm_medium=material-page&utm_campaign=site-2026&utm_content=pa12-decision) No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[2] Prices: AMT list prices, excluding tax and shipping; confirmed in your formal quote. [Not sure which system? Help me choose](https://amtechnologies.com/configurator/) ## Sources 1. [Vapor smoothing consumables: PostPro Pure (FA5802), FA326 and FA9202](https://amtechnologies.com/products/vapor-smoothing/consumables/) · AMT · read Oct 6, 2026 2. [PostPro benchmarking: send us your 3D printed parts](https://benchmarking.amtechnologies.com/) · AMT · read Oct 6, 2026 3. [Vapor smoothing voxeljet's HSS PA12 with AMT PostPro (whitepaper)](https://amtechnologies.com/resources/whitepapers/vapor-smoothing-voxeljets-hss-pa12-with-amt-postpro/) · AMT · Feb 6, 2024 4. [Performance improvements of vapor smoothed SLS PA2200 parts (whitepaper)](https://amtechnologies.com/resources/whitepapers/performance-improvements-of-vapour-smoothed-sls-pa2200-parts/) · AMT · Jan 8, 2024 5. [Flame-retardant 3D-printed parts with UL94 V-0 compliance (Protolabs case study)](https://amtechnologies.com/resources/case-studies/flame-retardant-3d-printed-parts/) · AMT · Jun 3, 2026 6. [Vapor smoothing of HP MJF parts with sustainable PostPro Pure consumable (whitepaper)](https://amtechnologies.com/resources/whitepapers/vapor-smoothing-of-hp-multi-jet-fusion-mjf-parts-with-amts-sustainable-postpro-pureconsumable/) · AMT · Jun 20, 2025 7. [AMT PostPro brochure: automated post-processing systems for additive manufacturing, V4.0 (June 2026)](https://info.amtechnologies.com/download-document?document_name=brochure) · AMT · Jun 2026 8. [PostPro compatible material list: PostPro Pure, FA5802, V3.2](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Specification%20Sheets/AMT_MATERIALS_POSTPRO_SF_PURE_EN.pdf?ver=2) · AMT · Nov 2024 9. [PostPro compatible material list: FA326, V6.1](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Specification%20Sheets/AMT_MATERIALS_POSTPRO_SF_FA326_EN.pdf?ver=2) · AMT · Apr 2025 10. [Vapor smoothing: SF and X-series family page and SFX, SF2X, SF50, SF100 product pages](https://amtechnologies.com/products/vapor-smoothing/) · AMT · read Oct 6, 2026 · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sfx-desktop-vapor-smoothing-system/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf2x/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf50/) · also [AMT](https://amtechnologies.com/products/vapor-smoothing/postpro-sf100/) 11. [How vapor smoothing helps 3D-printed rally car parts perform in extreme racing conditions (ABConcept case study)](https://amtechnologies.com/resources/case-studies/3d-printed-rally-car-parts/) · AMT · Dec 10, 2025 12. [How Norden improved efficiency with vapor smoothing for production machinery (case study)](https://amtechnologies.com/resources/case-studies/vapor-smoothing-for-production-machinery/) · AMT · Nov 27, 2025