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

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Pot STL 3D file, inner: base Ø50 mm, top Ø80 mm, height 70 mm - wall thickness 2 mm

Mounting bracket 120×120 mm STL file, thickness 8 mm, hole diameter 5 mm

Round air vent STL file ∅ 300 mm, slat angle: 30° with central reinforcement

Round-to-Rectangular Tube Adapter STL file ⌀125 mm to 60×60 mm, thickness 3 mm

Round-to-Rectangular Tube Adapter STL file ⌀60 mm to 50×10 mm, thickness 2 mm + offset

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

Small parts organizer with 4 drawers 100×10×50 mm STL 3D file, thickness: 2 mm

Small parts organizer with 25 drawers 40×30×50 mm STL 3D file, thickness: 2 mm

Star-pattern connector 10 ways STL file – Outer diameter 30 mm, wall thickness 3 mm

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

Enclosure with screw-mounted lid STL file: 90×60×60 mm (with ventilation on the lid and under the enclosure) 📦 #1791

2 object(s) - format STL

Latest user-generated 3D models

Star-pattern fitting 3 ways STL file – Outer diameter 15 mm, wall thickness 1.5 mm 📦 #11352

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 #2064

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 35 mm - Height: 63 mm, Shell: 2 mm

Download this cylindrical box model in STL format. Its diameter is 35 mm and its height is 63 mm. The walls have a thickness of 2 mm. A large fillet located at the bottom of the box makes it easier to grip objects present inside.

Parameter	Value	Unit
external diameter	35	mm
total height	63	mm
wall thickness	2	mm
fit clearance	0.1	mm
inner bottom fillet	5	mm

📦 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 #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 #1344

2 object(s)

- format STL

Round box with lid STL file ⌀ 110 mm - Height: 25 mm, Shell: 3 mm

Get this cylindrical box in STL format. Its diameter is 110 mm and its total height is 25 mm. The wall width is 3 mm. A fillet located at the bottom of the box makes it easier to grip objects.

Parameter	Value	Unit
external diameter	110	mm
total height	25	mm
wall thickness	3	mm
fit clearance	0.1	mm
inner bottom fillet	1	mm

📦 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 #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 #4429

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀103 mm to 290×28 mm, thickness 3 mm

Download this model in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀103 mm and a rectangular section with internal dimensions 290×28 mm. The wall thickness is 3 mm and the total length is 148 mm.

Parameter	Value	Unit
cylinder outer diameter	103	mm
cylinder inlet length	50	mm
rectangle internal length	290	mm
rectangle internal height	28	mm
rectangle inlet length	50	mm
offset Z	0	mm
offset Y	0	mm
total length	148	mm
thickness	3	mm
chamfer	no chamfer

📦 Model #2702

2 object(s)

- format STL

Small parts organizer with 9 drawers 20×10×30 mm STL 3D file, thickness: 2 mm

File of a multi-drawer box in STL format. This model contains 9 boxes, arranged in 3 rows and 3 columns. Practically speaking, this means 3 rows of 3 boxes. Each box measures 20 mm wide, 10 mm high, and 30 mm deep. The wall thickness is 2 mm. The total size of the structure are 81.5 x 45.5 x 36 mm. All the objects in this model were designed to be printed without support.

Parameter	Value	Unit
number of rows	3
number of columns	3
inner drawer depth	30	mm
inner drawer width	20	mm
inner drawer height	10	mm
wall thickness	2	mm
removable divider	none

📦 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 #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 #4088

2 object(s)

- format STL

Protective grid STL 3D file, 100x70mm, mesh: 3mm

Honeycomb rectangular grid model in STL format. The overall size is 100x70 mm, with fine 3 mm cell size for strong protection. A secondary color border highlights the perimeter. This type of grid serves both protection and ventilation roles.

Parameter	Value	Unit
length or center-to-center	100	mm
width or center-to-center	70	mm
mesh size	3	mm
dual color	yes
holes	no

📦 Model #2274

1 object(s)

- format STL

Mounting bracket 100×200 mm STL file, thickness 12 mm, hole diameter 5 mm

3D model of a mounting bracket with reinforcement in STL format. The dimensions are 100 mm in length, 200 mm in height, 25 mm in width, and 12 mm in thickness. The drill holes have a diameter of 5 mm. Chamfers are done to the holes to improve the seating of the heads. The reinforcing bar enhances mechanical strength and provides two clearances for screwdriver access. This bracket prints without support, placed flat on the build plate.

Parameter	Value	Unit
length	100	mm
height	200	mm
width	25	mm
thickness	12	mm
hole diameter	5	mm
chamfer on the holes	yes

📦 Model #1531

1 object(s)

- format STL

Pipe elbow STL 3D file 90° ⌀OD: 18 mm ⌀ID: 16 mm thickness: 1 mm

Model of an elbow with a 90° angle in STL format. This pipe elbow features an external diameter of 18 mm and an internal diameter of 16 mm. The tube thickness is therefore 1 mm. The ends feature fillets to make it easier to insert.

Parameter	Value	Unit
outer diameter	18	mm
inner diameter	16	mm
angle	90	°
end fillets	yes

📦 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 #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 #1683

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀280 mm to 100×100 mm, thickness 3 mm

Download this 3D file in STL format of a round-to-rectangular adapter with an outer diameter of ⌀280 mm and a rectangular section with inner dimensions 100×100 mm. The shell thickness is 3 mm and the total length is 200 mm. Chamfers are present on the outside of the cylindrical end and on the inside of the rectangular end to ease insertion.

Parameter	Value	Unit
cylinder outer diameter	280	mm
cylinder inlet length	25	mm
rectangle internal length	100	mm
rectangle internal height	100	mm
rectangle inlet length	50	mm
offset Z	0	mm
offset Y	0	mm
total length	200	mm
thickness	3	mm
chamfer	chamfers on ...

📦 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 #3724

1 object(s)

- format STL

Protective grid STL 3D file, center-to-center: 300x106mm, mesh: 10mm - Ø6mm

Download this 3D honeycomb protective rectangular grid model in STL format. Mounting holes are placed at the four corners (center-to-center 300x106 mm), each with a diameter of Ø6 mm. The overall dimensions reach 312x118 mm, with very large 10 mm cell size for maximum airflow. This grid functions as both a mechanical guard and a ventilation panel.

Parameter	Value	Unit
length or center-to-center	300	mm
width or center-to-center	106	mm
mesh size	10	mm
dual color	no
holes	yes
hole diameter	6	mm

📦 Model #1299

1 object(s)

- format STL

Round air vent STL 3D file ∅ 85 mm, slat angle: 35°

3D file of a round vent cover for air circulation in STL format. Its insertion diameter is 85 mm. The slats have an angle of 35° and a high thickness of 1.8 mm. This aeration grille has a thin flange of 5 mm. The total diameter of the model is 95 mm.

Parameter	Value	Unit
male diameter	85	mm
slat angle	35	°
slat thickness	1.8	mm
flange width	5	mm
central reinforcement	no

📦 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 #1111

2 object(s)

- format STL

Round box with lid STL file ⌀ 50 mm - Height: 45 mm, Shell: 2 mm

Get this cylindrical organizing box in STL format. Its diameter is 50 mm and its total height is 45 mm. The wall thickness is 2 mm.

Parameter	Value	Unit
external diameter	50	mm
total height	45	mm
wall thickness	2	mm
fit clearance	0.1	mm
inner bottom fillet	0	mm

📦 Model #2852

1 object(s)

- format STL

Tubing adapter STL file ⌀ 17–16 mm (Length: 25 mm)

Inline tube reducer ⌀17 mm to ⌀16 mm in STL 3D format. Length of this sleeve is 25 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 10 mm, the smaller one of 10 mm as well. The ends have no fillet.

Parameter	Value	Unit
side A length	10	mm
side A outer diameter	17	mm
side A thickness	2	mm
side B length	10	mm
side B outer diameter	16	mm
side B thickness	2	mm
transition length	5	mm
axis offset	0	mm
ends fillet	no fillet

📦 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 #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 #784

1 object(s)

- format STL

Rectangular prism STL file 80×82×30 mm

Download this 3D model of a box as an STL file. The final dimensions are 80×82×30 mm. A small fillet softens all the sides.

Parameter	Value	Unit
length	80	mm
width	82	mm
height	30	mm
fillet radius	2	mm

📦 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 #905

1 object(s)

- format STL

U-shaped handle STL 3D file 50×100×10 mm (Center-to-center 90 mm)

Download this STL 3D file of a simple U-shaped drawer handle. The external dimensions are 50×100×10 mm. This handle has a square profile and a 90-degree transition. The holes are 5 mm diameter and have a 90 mm center-to-center distance.

Parameter	Value	Unit
width	50	mm
length	100	mm
thickness	10	mm
shape (0:square,1:circle)	0
transition (0:right,1:rounded)	0
fillet radius	0	mm
hole diameter	5	mm

📦 Model #2015

1 object(s)

- format STL

Pipe elbow STL 3D file 180° ⌀OD: 40 mm ⌀ID: 36 mm thickness: 2 mm

Model of a pipe elbow with a 180° angle in STL format. This pipe elbow features an outer diameter of 40 mm and an inner diameter of 36 mm. The tube thickness is therefore 2 mm.

Parameter	Value	Unit
outer diameter	40	mm
inner diameter	36	mm
angle	180	°
end fillets	no

📦 Model #3580

1 object(s)

- format STL

Shelf bracket 125×100 mm STL file, thickness 12 mm, hole diameter 5 mm

Download this file of an angle bracket with a central reinforcing bar in STL 3D format. The dimensions are 125 mm in length, 100 mm in height, 20 mm in width, and 12 mm in thickness. The mounting holes have a diameter of 5 mm. Chamfers are done to the holes to seat the screw heads. The reinforcing bar enhances mechanical strength and provides two clearances for fastening. This bracket prints without support, printed flat on the print bed.

Parameter	Value	Unit
length	125	mm
height	100	mm
width	20	mm
thickness	12	mm
hole diameter	5	mm
chamfer on the holes	yes

📦 Model #3147

1 object(s)

- format STL

Tubing adapter STL 3D file ⌀ 35–15 mm (Length: 55 mm)

Straight tube adapter ⌀35 mm to ⌀15 mm in STL 3D format. Length of this coupler is 55 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 5 mm, the smaller one of 30 mm. The ends are rounded on the inside.

Parameter	Value	Unit
side A length	5	mm
side A outer diameter	35	mm
side A thickness	2	mm
side B length	30	mm
side B outer diameter	15	mm
side B thickness	2	mm
transition length	20	mm
axis offset	0	mm
ends fillet	fillet on th...

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.