---
title: "Press-Fits and Snap-Fits After Smoothing | AMT PostPro"
description: "Designing press-fits, snap-fits and assemblies for vapor smoothed parts: published dimensional and mechanical results, and good practice for fits."
canonical: https://amtechnologies.com/community/guides/press-fits-and-assemblies/
updated: 2026-10-06
type: guide
---
Community guide Tips & tricks / Design for vapor smoothing

# Press-fits, snap-fits and assemblies after smoothing

Smoothed parts often end up in assemblies. Two things change that you can design for: size, a little, and mechanical behavior, often for the better.

- By AMT Team
- Guide
- 1 min read
- Updated Oct 2026
- Sources[1,2]

## Size

AMT whitepapers measured dimensional change after vapor smoothing of 0.39 mm (0.4%) on HSS PA12 and a maximum of 0.4% on SLS PA2200. Details in [Will vapor smoothing change my part’s dimensions?](https://amtechnologies.com/community/guides/dimensional-change/).

## Mechanical behavior

The same whitepapers measured:

- **Elongation at break: +38.1% (XY)[1]** on HSS PA12 (Feb 2024). More stretch before breaking is good news for snap-fits and clips.
- **Burst pressure: up to +7%[2]** on SLS PA2200 (Jan 2024).

These are results for specific materials and test pieces. Treat them as a reason to test, not as design values.

## Good practice for fits

- **Design the fit, then validate it on smoothed parts.** Prototype the mating pair through the same route you will use in production.
- **Mark the critical faces** when you send parts for a [benchmark](https://benchmarking.amtechnologies.com/submit?utm_source=amtechnologies.com&utm_medium=community-page&utm_campaign=site-2026&utm_content=press-fits-and-assemblies-guide), and ask for them to be measured.
- **Keep contact points off mating faces** when racking. See [How part orientation and fixturing affect results](https://amtechnologies.com/community/guides/orientation-and-fixturing/).
- **Change one thing at a time.** If a fit is off, first check whether the printed part was already out before smoothing.

Forum · Over to you

How do you handle fits on smoothed parts? Share the fit type, the material and what worked. No customer drawings, please.

[Answer in the forum thread (opens the community forum in a new tab)](https://amtpostpro.discourse.group/t/press-fits-snap-fits-and-assemblies-after-smoothing/47)

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=community-page&utm_campaign=site-2026&utm_content=press-fits-and-assemblies-decision)

   No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[3]

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 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
2. [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
3. [PostPro benchmarking: send us your 3D printed parts](https://benchmarking.amtechnologies.com/) · AMT · read Oct 6, 2026