Which 3D Printing Technology Is Best for Functional Parts?
A practical guide to choosing strength, durability, and performance—without oversimplifying the answer
TLDR: For functional plastic parts, SLS and MJF are often default choices due to their strength, durability, and isotropic performance. However, FDM and SLA can also produce highly functional parts when the right materials and design approach are used. For metal functional parts, DLSM is the preferred technology. The best solution depends on how the part will be used, the environment it will operate in, and the material selected.
Table of Contents
Why There Is No Single “Best” Technology for Functional Parts
“Functional” does not mean the same thing for every project.
A functional part might need to:
- Support load or stress
- Withstand heat, UV, or moisture
- Fit precisely within an assembly
- Be produced quickly and cost-effectively
- Last for years or only for testing
Because of this, functional performance is determined by three factors working together:
- Printing technology
- Material selection
- Design intent
Technology alone is never the full answer.
Rule of Thumb: Start Here
If you need a quick default starting point:
- End-use plastic parts → SLS or MJF
- Cost-effective functional prototypes → FDM (FFF)
- High-precision functional parts → SLA with engineering resins
- Metal functional parts → DLSM
This rule of thumb is useful—but it’s not the whole story.
SLS & MJF: The Default Choice for Functional Plastic Parts
SLS and MJF are often the safest default for functional plastic parts because they produce strong, isotropic components with excellent durability and repeatability.
SLS uses unfused powder as its support structure, encasing the part during printing and allowing for complex geometry without traditional supports. MJF uses thermal and fusing agents to create parts with consistent mechanical properties and faster production cycles.
Why they are default choices
- Strong in all directions
- Ideal for complex shapes and assemblies
- Suitable for end-use production
- Consistent part quality
Limitations
- Higher cost than FDM
- Surface finish may require post-processing
Best for: housings, snap-fit parts, assemblies, production components
FDM / FFF: Functional, Affordable, and Often Overlooked
FDM (FFF) remains one of the most effective technologies for functional parts—especially when cost, speed, and material flexibility matter.
With engineering materials like ABS, PETG, PC, carbon fiber nylon, ULTEM®, PEEK, and PEKK, FDM can produce parts that perform extremely well in real-world conditions.
Why FDM is functional
- Huge material range
- Excellent for tooling, fixtures, and enclosures
- Fast iteration and low cost
- Strong performance when properly designed
Limitations
- Layer-direction strength must be considered
- Surface finish is rougher than resin or powder systems
Best for: tooling, jigs, fixtures, enclosures, replacement parts
SLA: Functional When Materials Are Chosen Correctly
SLA is often dismissed as “visual only” because many standard resins are optimized for appearance rather than strength. This leads to the misconception that SLA parts are brittle.
In reality, SLA can produce highly functional parts when engineering-grade resins are used.
Modern SLA materials include:
- Tough and impact-resistant resins
- High-temperature resins
- Reinforced engineering resins
These materials enable SLA to produce precise, durable functional parts, especially where tolerances matter more than raw strength.
Best for: small mechanical parts, fixtures, enclosures, medical and technical components
Material Choice Often Matters More Than the Printer
A part printed in the wrong material will fail regardless of technology.
For example:
- An SLA tough resin part may outperform PLA
- A carbon fiber nylon FDM part can rival SLS strength
- A high-temperature SLA resin can survive environments that standard plastics cannot
This is why Kemperle focuses on material-first evaluation, not machine-first recommendations.
Environmental & Performance Factors to Consider
Before choosing a technology, evaluate:
- Heat and temperature exposure
- UV and outdoor conditions
- Moisture and humidity
- Chemical contact
- Repeated loading and wear
- Tolerance and fit requirements
These factors often determine which material and process will succeed.
When Functional Parts Use Multiple Technologies
Many professional workflows combine multiple technologies. For example:
- SLA for design validation and tolerance checks
- FDM for functional testing
- SLS or MJF for final production
This layered approach reduces risk and ensures performance.
→ Learn more about scan-to-print workflows and reverse engineering
How to Choose the Right Technology for Your Functional Part
There is no universal answer. The best choice depends on:
- Material requirements
- Load and environment
- Accuracy and tolerance
- Quantity and budget
- Expected lifespan
That’s why Kemperle Industries takes a consultative, engineering-driven approach to every project.
Talk to Kemperle Industries About Your Functional Part
If you’re unsure which technology or material is right for your project, our team can help evaluate your requirements and recommend the best solution.
