SLA Resin · Industrial 3D Printing

Rigid 4000 Resin

A glass-filled SLA resin with stiffness in the range of PEEK and PEKK thermoplastics. Rigid 4000 prints with a smooth, matte, polished finish and resists heat and chemicals, for load-bearing parts that must not bend.

Drag & Drop Your Files Uploads are secure and confidential Upload Now Compare Material Specs

4.1 GPa

Tensile Modulus

PEEK-range stiffness

69 MPa

Flexural Strength

Resists bending loads

77 °C

Heat Deflection

@ 0.45 MPa thermal rating

5.3%

Elongation at Break

Rigid, not ductile

Real Rigid 4000 Parts

Actual Formlabs SLA prints in Rigid 4000 Resin, not renders.

Three impeller wheels with thin curved blades printed in Formlabs Rigid 4000 Resin — Impellers with thin curved blades. Glass filling is what keeps blades this thin from bowing.

Group of parts printed in Formlabs Rigid 4000 Resin, including housings, a funnel, a fan grille and mounts, on a blue background — Housings, funnels, grilles and mounts printed in Rigid 4000, in the smooth matte polished finish.

Summary & Key Takeaways

Stiffness Without Rigid 10K's Brittleness: A 4.1 GPa tensile modulus with 5.3% elongation at break, roughly five times the ductility of Rigid 10K.
Simulates PEEK and PEKK: Glass filling puts stiffness in the range of high-performance engineering thermoplastics.
Holds Thin Walls Flat: Dimensional stability suits thin-walled parts, turbine blades, and mounts that must not bow under load.
Smooth Polished Finish: Prints with a matte, polished surface that needs no secondary finishing for review or end use.

Compare Rigid 4000 to Other 3D Printing Materials

A quick, scannable comparison against the alternatives engineers usually weigh against it. All values are shown at once; use the buttons to focus on one comparison at a time.

Swipe to see all materials →

Tensile modulus, flexural strength, elongation at break, impact strength, and heat deflection temperature for Rigid 4000 Resin versus Rigid 10K Resin, Tough 2000 Resin, and SLS Glass Filled Nylon 12.
Property	Rigid 4000	Rigid 10K	Tough 2000	Nylon 12 GF SLS
Tensile modulus	4.1 GPa	11 GPa	1.8 GPa	2.8 GPa
Flexural strength	69 MPa	158 MPa	67 MPa	56 MPa
Elongation at break	5.3%	1%	79%	4%
Notched Izod impact	23 J/m	20 J/m	25 J/m	36 J/m
Heat deflection temp (0.45 MPa)	77 °C	238 °C	70 °C	170 °C
Support structures	Removable supports for overhangs	Removable supports for overhangs	Removable supports for overhangs	None required

Why Choose Rigid 4000 Resin?

The middle of the glass-filled range: markedly stiffer than a standard or tough resin, and far less brittle than Rigid 10K.

Load-Bearing Stiffness

A 4.1 GPa tensile modulus and 69 MPa flexural strength let brackets, mounts, and structural parts carry significant load with minimal deflection, replacing machined thermoplastic parts in many fixtures.

Dimensional Stability in Thin Sections

Glass filling reduces shrink and creep, so thin walls, fins, and blade profiles come out flat and stay flat, which is where unfilled resins tend to bow or warp over time.

Heat and Chemical Resistance

A 77 °C heat deflection temperature at 0.45 MPa plus resistance to common shop chemicals means parts survive warm environments, solvents, and mold release agents that soften standard resins.

Rigid 4000 Design Rules (DFM) at a Glance

Formlabs SLA design guidelines for Form 3 and Form 4 generation printers. Check your CAD feature dimensions against these limits before uploading your file.

Min. wall thickness (supported)	1.0 mm
Min. wall thickness (unsupported)	1.0 mm
Min. embossed detail	0.1 mm
Min. engraved detail (width & depth)	0.15 mm
Min. hole diameter	0.5 mm
Min. drain hole diameter	2.5 mm
Clearance between separate or moving parts	0.5 mm min
Max. unsupported overhang	5.0 mm · 10° min. angle from level
Max. single-part build size	353 × 196 × 350 mm

Anatomical bone models printed in Formlabs Rigid 4000 Resin, shown in the smooth matte white finish — Rigid 4000 holds fine surface detail, and prints in a smooth matte finish that needs no sanding.

Source: Formlabs SLA design specifications for Form 3 / Form 4 generation printers, adapted to hold walls to a higher minimum than Formlabs' published figures. Rigid 4000 is glass filled and stiffer than a standard resin, so thin walls and sharp internal corners concentrate stress more readily; keep fillets on load paths and stay at or above the minimum wall for handled or load-bearing features. These are general guidelines; cross-section, hole depth, and part geometry can shift the safe minimums for a specific design. Maximum build size reflects our largest-format SLA printer; actual build size depends on which machine your order routes to.

Frequently Asked Questions

Everything you need to know about designing, ordering, and using Rigid 4000 parts on Form Now.

What is Rigid 4000 Resin?

Rigid 4000 Resin is a glass-filled stereolithography (SLA) resin from Formlabs that is precise and offers stiffness similar to PEEK and PEKK thermoplastics. It prints with a smooth, matte, polished finish and is highly resistant to heat and chemicals.

How stiff is Rigid 4000 Resin?

Rigid 4000 Resin has a tensile modulus of 4.1 GPa and a flexural strength of 69 MPa, roughly twice the stiffness of Tough 2000 Resin. That lets load-bearing parts carry significant load without bending.

What is Rigid 4000 Resin used for?

Rigid 4000 Resin is commonly used for mounts and brackets, thin-walled parts, turbine blades, load-bearing parts, engineering-grade prototypes, and industrial parts that must withstand significant load without deflecting.

How does Rigid 4000 compare to Rigid 10K?

Rigid 10K is far stiffer and more heat resistant, at 11 GPa tensile modulus and a 238 °C heat deflection temperature versus 4.1 GPa and 77 °C for Rigid 4000. Rigid 4000 is the more forgiving of the two, with 5.3% elongation at break against Rigid 10K's 1%, so it is less prone to cracking during handling and assembly.

Is Rigid 4000 Resin brittle?

Rigid 4000 Resin is a stiff, glass-filled material with 5.3% elongation at break and a notched Izod impact strength of 23 J/m, so it is not ductile and is not suited to snap fits, living hinges, or parts that must flex. It is noticeably less brittle than Rigid 10K Resin, but for parts that need to bend choose Tough 1500 Resin or an SLS nylon instead.

What are the minimum wall thickness and hole size design rules for Rigid 4000?

Per Formlabs' SLA design specifications for Form 3 and Form 4 generation printers, we recommend a minimum wall thickness of 1.0 mm for both supported and unsupported walls, and holes should be at least 0.5 mm in diameter. Because Rigid 4000 is glass filled and stiff rather than ductile, keep fillets on load paths and avoid sharp internal corners in load-bearing features. Maximum single-part build size is 353 x 196 x 350 mm.