Flexible
The SLS 3D-printing process delivers a new level of design freedom, enabling highly complex geometries and a wider choice of materials for functional applications.
Certified and compliant
ISO 9001:2015 | AS9100D
Overview
SLS 3D printing is a proven additive manufacturing technology for producing durable, functional components with excellent mechanical properties. AMufacture partners benefit from one of the most advanced selective laser sintering fleets in the UK. That means more design freedom, consistent performance and scalable production without tooling.
Key properties
Durable
SLS can produce durable, load-bearing nylon components with stable mechanical properties, ideal for production at scale, not just prototyping.
Efficient
By packing multiple parts into a single build volume and harnessing our Digital Warehouse infrastructure, SLS unlocks efficiency gains that repeat with each production cycle.
Collaborative
AMufacture embeds digital manufacturing into your workflow, enabling end-to-end visibility, rapid repeatability and agile, collaborative design optimisation.
What is selective laser sintering (SLS) 3D printing?
Selective Laser Sintering (SLS) is a powder bed fusion process that uses a laser beam to selectively fuse powdered materials layer by layer. Unlike other non powder bed 3D printing technologies, SLS does not require support structures, as surrounding loose powder supports the part during the build.
This makes SLS particularly suited to functional prototypes and end-use components where strength, chemical resistance and design freedom are critical. It is widely used across industries that demand reliable, repeatable performance from additive manufacturing technology.
SLS is often compared with processes such as selective laser melting (SLM) and direct metal laser sintering (DMLS). However, these are typically used for metals. SLS, by contrast, focuses primarily on polymer powder materials such as nylon.
Why manufacturers choose SLS for functional parts
One of the key advantages of SLS printing is its proven performance in creating complex, robust, production-ready parts.
While it is slower than comparable technologies such as Multi Jet Fusion (MJF), it remains highly efficient and cost-effective for low- to medium-volume production runs. With AMufacture’s digitally enabled manufacturing embedded into your workflow, it becomes an integrated capability in a resilient, future-proofed supply chain – an on-demand tool for rapid iteration, repeatable production and operational continuity.
Design freedom
SLS 3D printing requires no support structures, enabling internal channels, lightweight lattice structures and other highly complex geometries. For you, that means easier problem-solving, accelerated innovation and less reliance on post-processing.
Production-ready outcomes
Manufacturers trust SLS for its repeatability and proven mechanical performance. It produces durable nylon components that are suitable for load-bearing applications, supporting a seamless transition from prototyping to end-use production.
Material options
SLS supports a range of engineering-grade materials tailored to specific mechanical, thermal and environmental requirements, enabling manufacturers to match material performance to real-world operating conditions.
Batch efficiency
With SLS 3D printing, multiple parts can be packed into a single build volume, keeping part costs consistent and supporting scalable, low-to-medium volume production without tooling constraints.
A trusted, UK-based SLS
printing service partner
AMufacture is the leading contract manufacturer in the additive manufacturing sector. We are not just production partners. We are true collaborators, integrating seamlessly into your workflow to enable rapid, repeatable production at scale.
An integrated partnership
From design optimisation to finishing and fulfilment, we work as an extension of your team, helping streamline workflows, accelerate development and ensure consistent, production-ready outcomes.
Industry-leading capabilities
AMufacture combines deep additive manufacturing expertise with advanced production infrastructure. We are constantly improving our capabilities to deliver more value and more flexibility, faster.
Digitally transformative
Our purpose-built digital infrastructure allows for real-time production visibility, agile collaboration and seamless repeat ordering through an IP-secure Digital Warehouse. For our partners, it becomes a single source of truth through every stage of production.
Post-processing capabilities
SLS parts are production-ready straight from the build. However, post-processing can enhance both performance and appearance. SLS parts often have a rough, grainy surface finish and internal porosity, which may require post-processing to achieve a smooth finish or waterproofing.
As your end-to-end production partner, AMufacture offers a wide range of in-house finishing and assembly services to ensure optimal real-world performance.
For SLS components, the most beneficial secondary options include:
- Surface finishing: including bead blasting for a uniform finish, tumbling for smoother edges and vapour smoothing to seal pores and boost strength.
- Assembly: compatible methods include snap-fit features, threaded inserts, adhesive bonding and mechanical fastening.
These processes allow SLS parts to integrate seamlessly into larger assemblies or end-use applications.
Cross-industry expertise
AMufacture’s expertise in additive manufacturing spans multiple industries. Our digitally enabled SLS 3D printing service enables clients across sectors to scale manufacturing, accelerate innovation and create production-ready parts for a wide range of industry-specific applications.
SLS 3D printing knowledge bank
How does SLS 3D printing work?
The SLS 3D-printing process follows a precise, repeatable sequence within a controlled build chamber:
- Powder preparation: a thin layer of polymer powder is spread evenly across the powder bed.
- Laser sintering: a high-power laser scans the cross-section of the part, heating powder particles to just below their melting point so they fuse together.
- Layer-by-layer build: once a layer is complete, the build platform lowers slightly (typically by 0.1 mm or less, or between 50 and 200 microns), and a new layer of powder is applied.
- Repeat scanning: the laser continues to trace each layer, building the part from the bottom up.
- Cooling phase: the entire powder bed is allowed to cool gradually to prevent warping and ensure consistent mechanical properties.
- Depowdering: finished SLS parts are removed from the powder bed, and excess loose powder is recovered and reused where possible.
This selective laser sintering process produces parts with strong interlayer bonding and reliable performance across all axes.
SLS printing capabilities and technical specifications
SLS is a manufacturing-grade process. However, like any production method, it comes with practical constraints. Typical capabilities include:
- Layer thickness: ~0.08 to 0.12 mm
- Dimensional accuracy: ±0.3% (subject to geometry and orientation)
- Minimum feature size: ~0.7 to 1.0 mm
- Minimum wall thickness: ~1.0 mm (thicker recommended for durability)
- Build volumes: vary by machine; can be up to 1000 mm in one axis
- Surface finish: naturally matte and slightly grainy
Because parts are built within a powder bed, multiple components can be nested efficiently within a single build. This makes SLS printing service options highly cost-effective for batch production.
However, factors such as thermal stress, laser scan speed and part geometry can influence outcomes. Large flat surfaces or abrupt changes in section thickness may require design adjustments to minimise distortion.
SLS 3D printing materials and typical properties
SLS 3D printing can utilise a variety of materials, including thermoplastic elastomers (TPE), polyaryletherketones (PAEK) and polypropylene (PP). SLS materials are typically high-performance thermoplastics in powder form, selected for their durability and versatility, and comparable to parts manufactured using conventional methods like injection moulding.
Common SLS materials
- PA12 (standard nylon): polyamide 12 is one of the most commonly used, for its excellent balance of mechanical properties, cost-effectiveness and ease of use.
- PA11: a more flexible and impact-resistant option.
- Polypropylene (PP): valued for its chemical resistance and low density, making it suitable for producing fully functional, lightweight parts.
- Glass-filled or mineral-filled nylons: both PA11 and PA12 (Nylon 11 and Nylon 12) can be reinforced with materials such as glass and carbon fibre to create composites with enhanced properties.
- Flame-retardant grades of PA11 and PA12: specially formulated to enhance safety in critical applications.
Typical SLS material properties
- Excellent mechanical properties
- High chemical resistance
- Good thermal stability
- Strong wear resistance
- Consistent mechanical properties across axes
SLS nylon is particularly popular due to its balance of strength, flexibility, and environmental resistance. It performs well in demanding applications such as housings, enclosures and interior components.
SLS vs SLA printing
SLS and SLA (stereolithography) serve different purposes within additive manufacturing.
In short, SLA is typically used for appearance and precision, while SLS is preferred for performance and durability.
SLS advantages
- No support structures required
- Stronger, more durable parts
- Better suited to functional prototypes and end-use parts
- Superior heat and chemical resistance
SLA advantages
- Higher surface detail and smoother finish
- Ideal for visual models and fine features
SLS vs MJF printing
SLS and Multi Jet Fusion (MJF) are both powder bed technologies, but they differ in how energy is applied.
The bottom line: MJF is faster and can produce superior parts to SLS on a like-for-like basis. However, SLS allows for a broader choice of materials, making it the preferred option when specific mechanical properties are required.
SLS
- Uses a laser to trace each layer point-by-point
- Broader material range
- Typically larger build volumes
- Slightly more variation in thermal distribution
MJF
- Uses agents and infrared energy across entire layers
- Faster build speeds
- More uniform thermal exposure
SLS design guidelines
Designing for SLS printing can significantly reduce lead times and quoting friction. AMufacture partners can harness design optimisation support and advanced implicit modelling capabilities, accelerating iteration and delivering parts based on real-world data, not guesswork.
While exact limits depend on geometry and material, the following guidelines are widely accepted:
Because the SLS process uses loose powder as support, complex geometries such as internal channels, lattice structures and interlocking parts can be produced in a single build.
Achieving high dimensional accuracy in SLS can be challenging due to factors such as powder layer thickness and laser focus, which can affect the final part dimensions.
Recommended starting points
- Wall thickness: ≥1.0 mm (2.0 mm recommended for robustness)
- Feature size: ≥0.7 mm for reliable detail
- Clearance for moving parts: ≥0.3 to 0.5 mm
Key considerations
- Escape holes: required for enclosed volumes to remove powder
- Avoid large flat surfaces: add ribs or curvature to reduce warping
- Uniform wall thickness: helps maintain consistent cooling
FAQs
Can SLS 3D printing be used for low-volume production as well as prototyping?
Yes. SLS printing supports both rapid prototyping and low-to-medium volume production by efficiently nesting multiple parts in a single powder bed.
What factors affect the cost of SLS printing?
Cost is influenced by part volume, material choice such as SLS nylon, packing density in the powder bed and any required post-processing.
Is SLS better than FDM?
SLS 3D printing typically produces stronger, more accurate parts with better mechanical properties than FDM. This often makes it more suitable for functional and production applications.
However, FDM offers different material options that may better suit your requirements. AMufacture can advise on materials and manufacturing processes to ensure the best fit for your project.
How accurate is SLS compared to other additive manufacturing technologies?
Selective Laser Sintering typically achieves around ±0.3% accuracy, delivering consistent mechanical properties suitable for functional parts.
Explore more services
With AMufacture’s best-in-class 3D printing fleet, you unlock more ways to deliver on production goals and bolster supply chain resilience.
Multi Jet Fusion (MJF)
A powder-based process that uses fusing agents and thermal energy to produce strong, consistent parts with exceptional speed and batch-production efficiency.
Best for: end-use parts, scalable production, rapid iteration
Digital Light Processing (DLP)
A resin-based process that harnesses projected light to cure entire layers in one go, enabling rapid production of highly detailed parts.
Best for: fine detail, small parts, smooth finishes
Stereolithography (SLA)
A laser-based process that produces parts with exceptional surface quality and high accuracy.
Best for: accuracy, smooth finishes, visual prototypes
Fused Deposition Modelling (FDM)
A material extrusion process that uses durable thermoplastics to build parts layer by layer.
Best for: large components, durability, tooling
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