Free custom STL files and 3D models for 3D printers

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Small parts organizer with 30 drawers 30×20×50 mm STL 3D file, thickness: 2 mm

L-bracket 250×100 mm STL file, thickness 8 mm, hole diameter 6 mm

Round box with lid STL 3D file ⌀ 45 mm - Height: 100 mm, Shell: 2 mm

Distribution manifold 3 ways STL file – Outer diameter 50 mm, wall thickness 10 mm

Pipe elbow STL 3D file 10° ⌀OD: 40 mm ⌀ID: 34 mm thickness: 3 mm

Pot STL file, inner: base Ø40 mm, top Ø40 mm, height 40 mm - wall thickness 2 mm

Rectangular tube adapter STL file 100x40 mm to 80x80 mm – transition: 80 mm

Pot STL 3D file, inner: base Ø100 mm, top Ø100 mm, height 40 mm - wall thickness 6 mm

L-bracket 200×200 mm STL file, thickness 5 mm, hole diameter 6 mm

Oval hose adapter STL 3D file 140x40 mm to 130x35 mm – transition: 40 mm

Browse a growing library of free STL files and 3D models — or generate custom parts online to your exact specs.

Featured Model of the Day

Small parts organizer with 16 drawers 100×100×100 mm STL 3D file, thickness: 3 mm 📦 #2678

2 object(s) - format STL

Latest user-generated 3D models

Tubing adapter STL file ⌀ 150–100 mm (Length: 90 mm) 📦 #9698

1 object(s) - format STL

From the Blog

Why Modeling Strategy Matters in Procedural CAD Modeling

2025-12-14 · 3D Modeling · sylvain

Why does modeling strategy matter so much in procedural CAD? Two scripts can produce the exact same geometry while showing very different generation times.

Using a concrete build123d example, this article explains why certain operations, such as fillets, become expensive when repeated at scale, and how a simple change in approach can drastically reduce computation time.

A clear overview of the key challenges in procedural modeling, highlighting the direct impact of design choices on CAD engine performance.

Read the article

A selection of custom 3D models

📦 Model #3502

1 object(s)

- format STL

Protective grid STL 3D file, 60x60mm, mesh: 8mm

Download this 3D square honeycomb grid model in STL format. The overall size is 60x60 mm, with wide 8 mm cell size for optimal air circulation. This type of grid serves both protection and ventilation roles.

Parameter	Value	Unit
length or center-to-center	60	mm
width or center-to-center	60	mm
mesh size	8	mm
dual color	no
holes	no

📦 Model #4201

1 object(s)

- format STL

Washer / Flat Gasket STL 3D file ⌀ID: 3.9 mm ⌀OD: 6.9 mm thickness: 4.3 mm

3D model of washer / gasket in STL 3D file format. This part features an inner diameter of ⌀3.9 mm and an outer diameter of ⌀6.9 mm. The total thickness is 4.3 mm. This part has no finish applied.

Parameter	Value	Unit
inner diameter	3.9	mm
outer diameter	6.9	mm
thickness	4.3	mm
finish	none

📦 Model #5925

2 object(s)

- format STL

Rectangular-base box with lid STL 3D file – 100×50×50 mm, wall thickness 3 mm

Rectangular-base box with a lid available as a STL 3D file. Box size: 100 mm × 50 mm × 50 mm (L × W × H). Wall thickness is 3 mm. Interior and exterior edges are rounded. A small clearance is included to ensure a precise fit between the box and the lid. The inner dimensions excluding rounding are 94 mm × 44 mm × 44 mm.

Parameter	Value	Unit
length	100	mm
width	50	mm
height	50	mm
wall thikness	3	mm

📦 Model #3068

1 object(s)

- format STL

Support bracket 180×170 mm STL file, thickness 8 mm, hole diameter 8 mm

Download this 3D model of an angle bracket with a central reinforcement in STL 3D format. The dimensions are 180 mm in length, 170 mm in height, 40 mm in width, and 8 mm in thickness. The holes are designed with a diameter of 8 mm. Chamfers are applied to the holes for a cleaner fit of the screws. The reinforcing bar improves rigidity and includes two passages for fastening. This bracket prints without support, printed flat directly on the build plate.

Parameter	Value	Unit
length	180	mm
height	170	mm
width	40	mm
thickness	8	mm
hole diameter	8	mm
chamfer on the holes	yes

📦 Model #4475

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 40–37 mm (Length: 118 mm)

Straight tube fitting ⌀40 mm to ⌀37 mm in STL format. Total length of this connector is 118 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 38 mm, the smaller one of 40 mm. The ends have a fillet to make tube connection easier.

Parameter	Value	Unit
side A length	38	mm
side A outer diameter	40	mm
side A thickness	5	mm
side B length	40	mm
side B outer diameter	37	mm
side B thickness	5	mm
transition length	40	mm
axis offset	0	mm
ends fillet	fillet on bo...

📦 Model #1483

1 object(s)

- format STL

Tube adapter STL file ⌀ 200–50 mm (Length: 80 mm)

Tube reducer ⌀200 mm to ⌀50 mm in STL 3D format. Total length of this junction is 80 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 30 mm, the smaller one of 30 mm as well. The ends have no fillet.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	200	mm
side A thickness	3	mm
side B length	30	mm
side B outer diameter	50	mm
side B thickness	3	mm
transition length	20	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #2831

2 object(s)

- format STL

Enclosure with screw-mounted lid STL file: 100×100×45 mm (with ventilation on the lid)

Download this enclosure model with screwed lid in 3D STL format. The dimensions are 100 mm long by 100 mm wide and 45 mm high. The lid only is 10 mm high. Wall thickness is 3 mm. This enclosure features significant cooling area on the lid.

Parameter	Value	Unit
length	100	mm
width	100	mm
total height	45	mm
lid height	10	mm
wall thickness	3	mm
screw margin	0.1	mm
fit clearance	0.1	mm
cooling level	10
cooling zone(s)	cutouts on t...

📦 Model #4497

1 object(s)

- format STL

Tubing adapter STL 3D file ⌀ 32–19 mm (Length: 65 mm)

Tube fitting ⌀32 mm to ⌀19 mm in STL 3D format. Length of this junction is 65 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 20 mm. The ends are not rounded.

Parameter	Value	Unit
side A length	35	mm
side A outer diameter	32	mm
side A thickness	2	mm
side B length	20	mm
side B outer diameter	19	mm
side B thickness	2	mm
transition length	10	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #2817

1 object(s)

- format STL

Pipe elbow STL file 90° ⌀OD: 64.6 mm ⌀ID: 61.4 mm thickness: 1.6 mm

Model of a pipe elbow with a 90° angle in STL format. This elbow features an external diameter of 64.6 mm and an internal diameter of 61.4 mm. The tube thickness is therefore 1.6 mm.

Parameter	Value	Unit
outer diameter	64.6	mm
inner diameter	61.4	mm
angle	90	°
end fillets	no

📦 Model #4503

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 125–80 mm (Length: 105 mm)

Straight tube coupler ⌀125 mm to ⌀80 mm in STL format. Total length of this junction is 105 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 40 mm. The ends are raw.

Parameter	Value	Unit
side A length	35	mm
side A outer diameter	125	mm
side A thickness	5	mm
side B length	40	mm
side B outer diameter	80	mm
side B thickness	5	mm
transition length	30	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #4512

1 object(s)

- format STL

Tube elbow STL file 45° ⌀OD: 40 mm ⌀ID: 25 mm thickness: 7.5 mm

3D model of an elbow with a 45° angle in STL format. This pipe elbow has an external diameter of 40 mm and an internal diameter of 25 mm. The tube thickness is therefore 7.5 mm.

Parameter	Value	Unit
outer diameter	40	mm
inner diameter	25	mm
angle	45	°
end fillets	no

📦 Model #1464

1 object(s)

- format STL

Round air vent STL 3D file ∅ 125 mm, slat angle: 45° with central reinforcement

Model of a round air vent for ventilation in STL format. Its insertion diameter measures 125 mm. The slats have an angle of 45° and a high thickness of 2 mm. A vertical reinforcement reinforces the slats. This 3D vent grille has a collar of 10 mm. The full diameter of the model is 145 mm.

Parameter	Value	Unit
male diameter	125	mm
slat angle	45	°
slat thickness	2	mm
flange width	10	mm
central reinforcement	yes

📦 Model #3491

1 object(s)

- format STL

Protective grid STL file, center-to-center: 107x107mm, mesh: 10mm - Ø5mm

3D square protective honeycomb grid model as a STL file. Mounting holes are placed at the four corners (center-to-center 107x107 mm), each with a diameter of Ø5 mm. The overall dimensions reach 117x117 mm, with very large 10 mm cell size for maximum airflow. This grid serves as both a protective guard and a ventilation panel.

Parameter	Value	Unit
length or center-to-center	107	mm
width or center-to-center	107	mm
mesh size	10	mm
dual color	no
holes	yes
hole diameter	5	mm

📦 Model #4476

1 object(s)

- format STL

Tubing adapter STL 3D file ⌀ 40–37 mm (Length: 115 mm)

Tube adapter ⌀40 mm to ⌀37 mm in STL 3D format. Length of this connector is 115 mm. The thickness of the tubes is identical: 5 mm. The larger-diameter tube has a sleeve length of 35 mm, the smaller one of 40 mm. The ends are rounded to facilitate the connection of the two tubes.

Parameter	Value	Unit
side A length	35	mm
side A outer diameter	40	mm
side A thickness	5	mm
side B length	40	mm
side B outer diameter	37	mm
side B thickness	5	mm
transition length	40	mm
axis offset	0	mm
ends fillet	fillet on bo...

📦 Model #2390

1 object(s)

- format STL

Round air vent STL 3D file ∅ 115 mm, slat angle: 45°

3D file of a round grille for air circulation in STL format. Its male diameter is 115 mm. The slats have an angle of 45° and a high thickness of 2 mm. This ventilation grille has a collar of 10 mm. The full diameter of this model is 135 mm.

Parameter	Value	Unit
male diameter	115	mm
slat angle	45	°
slat thickness	2	mm
flange width	10	mm
central reinforcement	no

📦 Model #4396

1 object(s)

- format STL

Honeycomb grid STL file, 250x250mm, mesh: 10mm

Square grid model as a STL file. The overall size is 250x250 mm, with very large 10 mm cell size for maximum airflow. This grid serves as both a protective guard and a ventilation panel.

Parameter	Value	Unit
length or center-to-center	250	mm
width or center-to-center	250	mm
mesh size	10	mm
dual color	no
holes	no

📦 Model #4414

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 134 mm - Height: 20 mm, Shell: 2 mm

Get this circular box model in 3D STL format. Its diameter is 134 mm and its total height is 20 mm. The wall thickness is 2 mm. A fillet located at the bottom of the box makes it easier to grip objects.

Parameter	Value	Unit
external diameter	134	mm
total height	20	mm
wall thickness	2	mm
fit clearance	0.2	mm
inner bottom fillet	1	mm

📦 Model #1528

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀80 mm to 80×80 mm, thickness 3 mm

File in STL format of a round-to-rectangular adapter with an external diameter of ⌀80 mm and a rectangular section with internal dimensions 80×80 mm. The wall thickness is 3 mm and the total length is 50 mm. A chamfer is present on the outside of the cylindrical end to ease insertion.

Parameter	Value	Unit
cylinder outer diameter	80	mm
cylinder inlet length	15	mm
rectangle internal length	80	mm
rectangle internal height	80	mm
rectangle inlet length	15	mm
offset Z	0	mm
offset Y	0	mm
total length	50	mm
thickness	3	mm
chamfer	chamfer on t...

📦 Model #2257

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀76 mm to 160×60 mm, thickness 3 mm + offset

3D file in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀76 mm and a rectangular section with internal dimensions 160×60 mm. The shell thickness is 3 mm and the total length is 200 mm. The adapter has an offset of 25 mm along the Z axis.

Parameter	Value	Unit
cylinder outer diameter	76	mm
cylinder inlet length	50	mm
rectangle internal length	160	mm
rectangle internal height	60	mm
rectangle inlet length	100	mm
offset Z	25	mm
offset Y	0	mm
total length	200	mm
thickness	3	mm
chamfer	no chamfer

📦 Model #3610

1 object(s)

- format STL

O-ring STL file ID 11 × CS 4 mm

STL file of O-ring with dimensions Internal diameter 11 mm by section thickness 4 mm. Outer diameter (OD) resulting is 19 mm.

Parameter	Value	Unit
inner diameter (ID)	11	mm
cross section (CS)	4	mm

📦 Model #3156

1 object(s)

- format STL

O-ring STL 3D file ID 70 × CS 10 mm

3D model of rubber ring with ID (inner diameter) 70 mm by thickness 10 mm. Outer diameter (OD, for outer diameter) is 90 mm.

Parameter	Value	Unit
inner diameter (ID)	70	mm
cross section (CS)	10	mm

📦 Model #2141

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀100 mm to 50×50 mm, thickness 2 mm

Download this 3D file in STL format of a round-to-rectangular adapter with an external diameter of ⌀100 mm and a rectangular section with internal dimensions 50×50 mm. The shell thickness is 2 mm and the total length is 200 mm.

Parameter	Value	Unit
cylinder outer diameter	100	mm
cylinder inlet length	25	mm
rectangle internal length	50	mm
rectangle internal height	50	mm
rectangle inlet length	15	mm
offset Z	0	mm
offset Y	0	mm
total length	200	mm
thickness	2	mm
chamfer	no chamfer

📦 Model #2520

1 object(s)

- format STL

L-bracket 150×110 mm STL 3D file, thickness 8 mm, hole diameter 6 mm

Model of a corner bracket reinforced in STL format. The dimensions are 150 mm in length, 110 mm in height, 50 mm in width, and 8 mm in thickness. The screw holes have a diameter of 6 mm. Chamfers are applied to the holes to improve the seating of the heads. The reinforcing bar enhances mechanical strength and includes two openings for fastening. This bracket prints without support, placed flat on the build plate.

Parameter	Value	Unit
length	150	mm
height	110	mm
width	50	mm
thickness	8	mm
hole diameter	6	mm
chamfer on the holes	yes

📦 Model #3094

2 object(s)

- format STL

Enclosure with screw-mounted lid STL 3D file: 60×50×20 mm

Download this enclosure with screwed lid in 3D STL format. The dimensions are 60 mm long by 50 mm wide and 20 mm high. The lid only is 10 mm high. Side thickness is 2 mm. The enclosure does not have cooling.

Parameter	Value	Unit
length	60	mm
width	50	mm
total height	20	mm
lid height	10	mm
wall thickness	2	mm
screw margin	0	mm
fit clearance	0.1	mm
cooling zone(s)	no cutouts

📦 Model #3079

1 object(s)

- format STL

Shelf bracket 200×200 mm STL file, thickness 5 mm, hole diameter 5 mm

File of a right-angle bracket with a central reinforcement in STL 3D format. The dimensions are 200 mm in length, 200 mm in height, 25 mm in width, and 5 mm in thickness. The mounting holes have a diameter of 5 mm. Chamfers are applied to the holes to improve the seating of the heads. The reinforcing bar reduces bending and includes two clearances for fastening. No support is needed to print this bracket, placed flat on the build plate.

Parameter	Value	Unit
length	200	mm
height	200	mm
width	25	mm
thickness	5	mm
hole diameter	5	mm
chamfer on the holes	yes

📦 Model #3057

1 object(s)

- format STL

Right-angle bracket 150×150 mm STL 3D file, thickness 6 mm, hole diameter 6 mm

3D file of a mounting bracket with a central reinforcement in STL format. The dimensions are 150 mm in length, 150 mm in height, 14 mm in width, and 6 mm in thickness. The screw holes are designed with a diameter of 6 mm. Chamfers are applied to the holes to improve the seating of the heads. The central reinforcement bar reduces bending and provides two clearances for screwdriver access. No support is needed to print this bracket, printed flat on the build plate.

Parameter	Value	Unit
length	150	mm
height	150	mm
width	14	mm
thickness	6	mm
hole diameter	6	mm
chamfer on the holes	yes

📦 Model #1949

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀30.5 mm to 27×15 mm, thickness 2 mm

File in STL format of a round-to-rectangular adapter with an outer diameter of ⌀30.5 mm and a rectangular section with internal dimensions 27×15 mm. The shell thickness is 2 mm and the total length is 50 mm.

Parameter	Value	Unit
cylinder outer diameter	30.5	mm
cylinder inlet length	20	mm
rectangle internal length	27	mm
rectangle internal height	15	mm
rectangle inlet length	8	mm
offset Z	0	mm
offset Y	0	mm
total length	50	mm
thickness	2	mm
chamfer	no chamfer

📦 Model #3612

1 object(s)

- format STL

Protective grid STL 3D file, center-to-center: 210x110mm, mesh: 10mm - Ø5mm

Download this rectangular protective honeycomb grid model in STL format. Mounting holes are placed at the four corners (center-to-center 210x110 mm), each with a diameter of Ø5 mm. The overall dimensions reach 220x120 mm, with very large 10 mm cell size for peak ventilation. This grid serves as both a protective guard and a ventilation panel.

Parameter	Value	Unit
length or center-to-center	210	mm
width or center-to-center	110	mm
mesh size	10	mm
dual color	no
holes	yes
hole diameter	5	mm

📦 Model #3910

1 object(s)

- format STL

O-ring STL 3D file ID 25 × CS 1.5 mm

STL file of sealing ring with dimensions ID (inner diameter) 25 mm / section thickness 1.5 mm. Outer diameter (OD) resulting is therefore 28 mm.

Parameter	Value	Unit
inner diameter (ID)	25	mm
cross section (CS)	1.5	mm

📦 Model #2464

1 object(s)

- format STL

Angle bracket 250×150 mm STL file, thickness 8 mm, hole diameter 6 mm

Download this 3D model of a mounting bracket with reinforcement in STL 3D format. The dimensions are 250 mm in length, 150 mm in height, 15 mm in width, and 8 mm in thickness. The drill holes have a diameter of 6 mm. Chamfers are applied to the holes to improve the seating of the heads. The reinforcing bar enhances mechanical strength and includes two passages for screwdriver access. No support is needed to print this bracket, placed flat on the build plate.

Parameter	Value	Unit
length	250	mm
height	150	mm
width	15	mm
thickness	8	mm
hole diameter	6	mm
chamfer on the holes	yes

STL: Advantages and Disadvantages for 3D Printing

The STL format is, without question, a cornerstone of 3D printing. This exchange format has established itself as the universal standard for representing 3D models ever since the early days of stereolithography. Its main strength lies in its simplicity: it describes the surface of an object using countless small triangles that form a mesh. This approach, known as tessellation, makes STL 3D files universally compatible with nearly all CAD software and slicers. If you’d like to learn more about this format, check out our article STL: What Is This 3D File Format?.

One of the major advantages of the format lies in this universality: whether you’re using a complex modeling program or a simpler design tool, you can export your 3D models in STL 3D format with near certainty that they’ll be interpreted correctly by your 3D printer. This ease of exchange has played a key role in the widespread adoption of 3D printing, allowing anyone to share and print objects without worrying about software compatibility. Once again, simplicity is its greatest strength.

However, that same simplicity also brings certain limitations. The triangle mesh, while effective for describing geometry, contains no information about colors, textures, or materials. For more advanced projects requiring these details, the STL format starts to show its weaknesses. Additionally, print quality depends directly on the fineness of the tessellation: too few triangles can lead to rough or faceted surfaces, while an overly dense mesh can make the file unnecessarily heavy.

Another notable drawback is the lack of unit management. An STL file doesn’t specify whether dimensions are in millimeters, centimeters, or inches, which can sometimes cause scaling errors when importing into a slicer. Despite these limitations, the STL format remains the go-to standard for converting your 3D models into G-code — the language your printer understands. It continues to be the preferred choice for its robustness and broad compatibility, even as newer formats like 3MF emerge for more specialized needs.

What is parametric modeling?

Parametric modeling is a fundamental approach in computer-aided design (CAD) that reshapes how 3D models are created and managed. Far from being a simple drawing technique, it represents a genuine design philosophy where objects are defined not by fixed shapes, but by variables and intelligent relationships.

This method makes it possible to modify the length, width, or diameter of a part and have the entire design adapt automatically, without the need to redraw everything. At the core of the process are parameters—numerical values (length, angle, thickness, etc.)—linked together through constraints and formulas. For instance, the diameter of a hole can be defined as half the width of a plate; if the width changes, the hole’s diameter instantly adjusts, ensuring the consistency of the design. This interdependence makes 3D models flexible and responsive to changes. One of the main advantages of parametric modeling lies in its ability to simplify customization and enable rapid iteration of designs.

Whether through modeling software such as Fusion 360 or FreeCAD, or through code-based libraries like build123d, this approach allows effortless exploration of a wide range of variations. Such flexibility is especially valuable across multiple fields—from mechanical engineering and architecture to consumer product design. It saves considerable time, reduces errors, and improves the performance of parts.

By defining design intent from the start through these parameters and constraints, the model preserves its integrity and functionality even after numerous modifications. It is a powerful way to transform an idea into a tangible object, ready to adapt to new situations.