Metal Filament 3D Printing Complete Guide: How to Make Real Metal Parts at Home with Sintering in 2026

“I want to make metal parts at home” — this is every maker’s ultimate dream, and it used to be synonymous with “impossible.” After all, everyone assumed you needed multi-million-dollar SLM (Selective Laser Melting) machines. But did you know that your desktop FDM printer costing a few hundred dollars can produce real stainless steel parts? Filaments infused with metal powder and binder are turning homes into miniature foundries.

Print Like Plastic, Fire Into Metal

The core of this technology is metal powder bound together with plastic (binder) and extruded into filament form. The printing process itself is virtually identical to regular PLA — just bump up the nozzle temperature slightly and swap to a wear-resistant nozzle.

The freshly printed object is called a “green part” — it feels like slightly fragile clay. When you debind and sinter this part through a specialized service (or your own small electric kiln), the binder burns away and the metal particles fuse through diffusion bonding, producing a metal part with 80-95% density (over 96% under optimal conditions).

Metal Filament Brand Comparison

As of 2026, there are three main lines of filaments available for desktop metal printing:

• The Virtual Foundry “Filamet” Series: Widest material range — 316L stainless steel, copper, bronze, tungsten, H13 tool steel, aluminum 6061, and more. About $70-150 per kg. Most popular among individual makers
• BASF “Ultrafuse Metal” Series: Focused on 316L and 17-4PH stainless steel. Uses proprietary Cold Metal Fusion (CMF) technology with a unique binder system for consistent sintering quality. Aimed at industrial applications
• Markforged “Metal X” System: Closed ecosystem with dedicated printer and filaments. Supports high-performance alloys including 17-4PH stainless, A2/D2 tool steel, and Inconel 625. Printer costs several hundred thousand dollars, but adoption is growing in R&D departments

For beginners, The Virtual Foundry’s Filamet 316L stainless steel has the lowest barrier to entry — you can start with your existing FDM printer like an Ender-3 or Prusa MK4.

Printer Prep: Just Swap the Nozzle for Metal Capability

No special modifications needed for metal filament printing. You just need two things:

• Hardened steel or ruby nozzle: Metal powder is extremely abrasive — brass nozzles wear out within hours. Hardened steel nozzles cost $5-10, ruby nozzles $50-80. Ruby is more economical long-term
• Nozzle temperature adjustment: Most metal filaments print at 180-220°C — slightly higher than PLA but similar to ABS. Heated bed at 60-80°C is recommended

Print speed should be kept to around 30-50mm/s. Slower than normal PLA, but this ensures proper layer adhesion of metal particles. Since trace amounts of gas from the binder component are released during printing, work in a well-ventilated environment.

The Alchemy of Calculating Shrinkage

There’s one aspect that requires expertise: shrinkage. During sintering, as the binder burns away, parts shrink approximately 16-20% in all directions. You need to scale up your model in advance using slicer software. Mastering this “scale factor” is the essential skill of the modern-day metalsmith. Once you nail the parameters, you can even produce hollow metal balls and nozzles with internal cooling channels.

Sintering: Where the Magic Happens

Sintering is the process that transforms the printed green part into actual metal. It’s both the most critical and most costly step.

Sintering Options

• Outsource to a sintering service: The most practical option. Mail your printed parts to Virtual Foundry or BASF partners for sintering and return shipping. A few dollars to a few hundred per part, with consistent quality
• Your own electric kiln: Small kilns reaching 1,200-1,400°C cost $3,000-8,000. Virtual Foundry also sells dedicated kilns. Large upfront investment, but pays off with frequent sintering
• Shared ceramic workshop: Some pottery kilns can reach 1,200°C+. Negotiating shared access with a local ceramic workshop is a viable hack

During sintering, the binder (plastic component) burns away completely and metal particles bond through diffusion. Shrinkage of 16-17% in XY and 19-20% in Z direction occurs. Incorporating this shrinkage into your CAD design scaling is mandatory.

Cost Revolution: 30-70% Cheaper Than CNC Machining

Traditional metalworking for complex shapes requires expensive machines and skilled operators. Investment casting (lost wax) involves lengthy pattern-making and mold-embedding processes. With the metal filament approach, material costs are about $70-150 per spool (1kg). Small parts cost just a few dollars. Lead time drops from weeks (with outsourcing) to days.

Limitations and Safety Precautions to Know

• Size limitations: With 16-20% shrinkage, a 100mm part becomes 80-84mm after sintering. Larger parts increase the risk of warping from shrinkage. Parts up to about 150mm are the practical limit
• Mechanical strength: 80-95% density means 5-20% porosity remains. Not suitable for high-stress structural components. Best for jigs, jewelry, prototypes, and decorative parts
• Surface finish: Post-sintering surfaces retain fine roughness. Mirror finishes require post-processing like polishing or tumble finishing
• Ventilation: Be cautious of binder gases during printing and organic combustion gases during sintering. Avoid working in enclosed spaces
• Warp prevention: Placing parts on alumina (aluminum oxide) powder during sintering is standard practice to prevent thermal deformation and minimize gravity-induced warping

Practical Workflow: 5 Steps to Your First Metal Part

Step 1: CAD Modeling — Create a model scaled to 120-125% of your target dimensions to account for shrinkage. Use the “Scale” function in Fusion 360 or FreeCAD. Standard values for 316L stainless: 1.19x in XY, 1.24x in Z.

Step 2: Slicer Settings — In OrcaSlicer or PrusaSlicer, set nozzle temperature 200-210°C, bed temperature 70°C, print speed 30-40mm/s, layer height 0.15-0.2mm. Minimum 70% infill, 100% recommended for structural parts. Retraction distance 1.5-2mm (direct drive).

Step 3: Print — Operations are nearly identical to PLA printing. Note that metal-filled filament is much heavier (about 4x the density of regular 1.75mm filament), so ensure your spool holder rotates smoothly. Turn on ventilation during printing.

Step 4: Debinding and Sintering — Send the green part to a sintering service or load it into your kiln. First, thermally decompose the binder at 400-600°C for several hours (debinding), then ramp up to 1,300-1,380°C and hold for 3-6 hours. Cool naturally inside the kiln.

Step 5: Post-Processing — Finish sintered parts with sandblasting or tumble polishing. Machine critical dimensions with drill and tap after sintering. For stainless steel, passivation treatment improves corrosion resistance.

Real-World Applications: What Can You Actually Make?

• Custom Jigs and Fixtures: Factory line jigs cost $500-1,000 each when CNC outsourced. Metal filament brings material costs down to a few dollars. Design changes just mean reprinting
• Jewelry and Accessories: Bronze or stainless steel rings, pendants, cufflinks. Combined with 3D scanning, you can create perfectly fitted custom rings
• Custom Heat Sinks: Copper filament enables heat sinks with complex internal cooling channels impossible to machine conventionally — documented cases of 30-50% improved cooling efficiency
• Restoring Discontinued Parts: Reverse-engineer obsolete parts from vintage cars, cameras, and machines through 3D scanning
• Prototype Validation: Test prototypes in the same material as the final product for accurate strength testing and fit checks — feedback that plastic prototypes simply cannot provide

What Is Cold Metal Fusion (CMF)? BASF’s Industrial-Grade Path

BASF’s Ultrafuse Metal series uses proprietary Cold Metal Fusion technology. The key difference from standard metal filaments (like Virtual Foundry) lies in the binder removal process.

Virtual Foundry’s kiln sintering directly burns off the binder with heat. CMF, by contrast, first chemically dissolves most of the binder using solvents (acetone or water) in a debinding step, then burns off the remainder at low temperature before proceeding to high-temperature sintering. This two-stage process reduces the risk of cracking during binder removal in larger parts, delivering more consistent quality.

CMF is also compatible with industrial MIM (Metal Injection Molding) sintering furnaces, making it easy to scale from prototyping to mass production. Adoption is growing more among R&D departments and startups for “pre-production testing” rather than individual makers.

FAQ

Is it really “metal”? How does it differ from plastic?

After sintering, it’s genuine metal. It’s magnetic, electrically conductive, and heat-resistant. However, compared to cast or forged metal, the density is lower (80-95%), so mechanical strength is somewhat inferior. It’s more than adequate for decorative items and jigs.

Can I really start for under 0?

One spool of filament costs $70-150, and a hardened steel nozzle is about $5. If you already own an FDM printer, you can start printing for under $200. However, sintering requires either an outsourced service (a few dollars to hundreds per part) or a kiln ($3,000-8,000) — that’s a separate cost.

What metals are available?

The most common is 316L stainless steel — corrosion-resistant and beginner-friendly. Other options include 17-4PH stainless (high strength), copper (for electrical/thermal applications), bronze (decorative/jewelry), and tungsten (ultra-high density/radiation shielding).

Is it really cheaper than CNC machining?

For complex shapes in small batches (1-50 pieces), costs can be 30-70% lower than CNC. However, for simple shapes or mass production, CNC remains more economical. The biggest advantage of metal filament is producing hollow structures and internal channels at low cost — geometries that are impossible to machine.

Can I make food-safe items?

316L stainless is a food-grade material, but since sintered density isn’t 100%, microscopic pores could harbor bacteria. Not recommended for cookware or utensils. Decorative cutlery is acceptable, but not items in prolonged direct contact with food.

Are there metal filaments that don’t require sintering?

Yes. ColorFabb’s SteelFill and BronzeFill are PLA/PHA-based filaments mixed with metal powder — no sintering required, providing metallic texture and weight. However, these are “plastic that looks like metal” — no magnetism, no conductivity, and heat resistance is only PLA-level (~60°C). Fine for display models and decorative pieces, but not functional parts.

How long can green parts be stored?

With proper storage, several months is fine. Keep away from moisture and direct sunlight, ideally in an airtight container. Green parts are very fragile, so handle with care. When shipping to a sintering service, pack with plenty of cushioning material.

The Future of Metal 3D Printing: The Price Revolution Continues

As of 2026, metal filament prices of $70-150/kg are on a downward trend year over year. New entrants beyond BASF and Virtual Foundry continue to join the market, and competition is expected to drive further price drops.

Another notable trend is the falling cost of desktop sintering kilns. Small sintering furnaces that once cost over $10,000 are becoming available in the $3,000-5,000 range. For individual makers who found outsourced sintering costs to be a bottleneck, the barrier to in-house sintering is steadily lowering.

Furthermore, research into AI-powered shrinkage prediction software is progressing — technology that simulates sintering shrinkage patterns from 3D model geometry and automatically generates corrected models. Once commercialized, this would automate the biggest barrier in metal 3D printing: predicting shrinkage.

Summary: The Age of a Foundry on Your Desk

Metal filament 3D printing is no longer experimental. Thanks to the ecosystem pioneered by Virtual Foundry, BASF, and Markforged, individual makers can now produce real metal parts.

Your first step: swap your printer’s nozzle to hardened steel and buy one spool of 316L stainless filament. Print it, send it to a sintering service, and when you hold that cold, heavy metal part in your hands a few days later, your concept of making will be forever changed. It’s a revolution that starts at under $200.

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