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

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Oval hose adapter STL file 60x20 mm to 60x20 mm – transition: 140 mm

Rectangular-base box with lid STL 3D file – 120×80×50 mm, wall thickness 3 mm

Tube adapter STL file ⌀ 16–12 mm (Length: 35 mm)

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

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

Honeycomb grille STL file, 200x200mm, mesh: 6mm

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

Tube adapter STL 3D file ⌀ 80–50 mm (Length: 80 mm)

Enclosure with screw-mounted lid STL file: 90×50×40 mm (with ventilation on the lid)

L-bracket 200×200 mm STL file, thickness 5 mm, hole diameter 6 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 2 drawers 135×42×135 mm STL 3D file, thickness: 2 mm 📦 #2415

2 object(s) - format STL

Latest user-generated 3D models

3 ways fitting STL file – Outer diameter 34 mm, wall thickness 2 mm 📦 #10744

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 #1926

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀150 mm to 150×50 mm, thickness 4 mm + offset

File in STL format of a round-to-rectangular adapter with an outer diameter of ⌀150 mm and a rectangular section with inner dimensions 150×50 mm. The wall thickness is 4 mm and the overall length is 100 mm. The adapter has an offset of 3 mm along the Y axis and 3 mm along the Z axis. Chamfers are applied on the outside of the cylindrical end and on the inside of the rectangular end to ease insertion.

Parameter	Value	Unit
cylinder outer diameter	150	mm
cylinder inlet length	30	mm
rectangle internal length	150	mm
rectangle internal height	50	mm
rectangle inlet length	30	mm
offset Z	3	mm
offset Y	3	mm
total length	100	mm
thickness	4	mm
chamfer	chamfers on ...

📦 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 #6422

2 object(s)

- format STL

Rectangular-base box with lid STL 3D model – 170×95×110 mm, wall thickness 3 mm

Rectangular box with a lid provided as a STL 3D file. Box size: 170 mm × 95 mm × 110 mm (L × W × H). Wall thickness is 3 mm. Both the inner and outer edges of the box are rounded. Built-in clearance allows the lid to fit accurately onto the box. The internal dimensions, excluding rounding, are 164 mm × 89 mm × 104 mm.

Parameter	Value	Unit
length	170	mm
width	95	mm
height	110	mm
wall thikness	3	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 #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 #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 #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 #768

1 object(s)

- format STL

Rectangular prism STL 3D file 100×42×57 mm

A 3D STL file of a box. Its overall dimensions are 100×42×57 mm. This model has no fillet on the sides.

Parameter	Value	Unit
length	100	mm
width	42	mm
height	57	mm
fillet radius	0	mm

📦 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 #4145

1 object(s)

- format STL

Honeycomb grille STL file, 195x80mm, mesh: 7mm

Download this rectangular protective grid file in STL format. The overall size is 195x80 mm, with wide 7 mm cell size to enhance ventilation. This grid acts as a protective guard while allowing airflow.

Parameter	Value	Unit
length or center-to-center	195	mm
width or center-to-center	80	mm
mesh size	7	mm
dual color	no
holes	no

📦 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 #3112

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 120 mm - Height: 40 mm, Shell: 3 mm

Download this cylindrical box in 3D STL format. Its diameter is 120 mm and its total height is 40 mm. The wall thickness is 3 mm. A large fillet located at the bottom of the box makes it easier to grip objects present inside.

Parameter	Value	Unit
external diameter	120	mm
total height	40	mm
wall thickness	3	mm
fit clearance	0.1	mm
inner bottom fillet	3	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 #3741

1 object(s)

- format STL

Tube clip Ø14 mm STL file · Flat head screw Ø3 mm

Download this 3D file of a Ø14 mm pipe support clip in STL format. The mounting is performed using a countersunk screw Ø3 mm. This snap-on pipe mount is intended for a stable hold and quick installation.

Parameter	Value	Unit
tube diameter	14	mm
hole diameter	3	mm
countersunk screw	yes

📦 Model #1151

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 147–49.9 mm (Length: 140 mm)

Straight tube connector ⌀147 mm to ⌀49.9 mm in STL format. Total length of this connector is 140 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 30 mm, the smaller one of 40 mm. The axes of the tubes are offset by 48 mm. The ends have a fillet on the outside to facilitate the connection of the two tubes.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	147	mm
side A thickness	2	mm
side B length	40	mm
side B outer diameter	49.9	mm
side B thickness	2	mm
transition length	70	mm
axis offset	48	mm
ends fillet	fillet on th...

📦 Model #1513

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 16–12 mm (Length: 30 mm)

Straight tube fitting ⌀16 mm to ⌀12 mm in STL 3D format. Final length of this adapter is 30 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 10 mm, the smaller one of 15 mm. The ends have a fillet to ease the connection.

Parameter	Value	Unit
side A length	10	mm
side A outer diameter	16	mm
side A thickness	2	mm
side B length	15	mm
side B outer diameter	12	mm
side B thickness	2	mm
transition length	5	mm
axis offset	0	mm
ends fillet	fillet on bo...

📦 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 #2420

3 object(s)

- format STL

Small parts organizer with 1 drawer 150×100×150 mm STL 3D file, thickness: 2 mm

Download this 3D file of a DIY organizer in STL format. This model features 1 drawer, arranged in 1 rows and 1 columns. In detail, this means 1 rows of 1 drawers. Each drawer measures 150 mm wide, 100 mm high, and 150 mm deep. The wall thickness is 2 mm. The drawer comes with 2 dividers, allowing up to 3 sections. The total size of the structure come to 158.5 x 106.5 x 156 mm. All the objects in this model are intended to be printed without support generation.

Parameter	Value	Unit
number of rows	1
number of columns	1
inner drawer depth	150	mm
inner drawer width	150	mm
inner drawer height	100	mm
wall thickness	2	mm
removable divider	two divider ...

📦 Model #1908

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 132 mm - Height: 75 mm, Shell: 2 mm

Get this round storage box in 3D STL format. Its diameter is 132 mm and its total height is 75 mm. The wall thickness is 2 mm.

Parameter	Value	Unit
external diameter	132	mm
total height	75	mm
wall thickness	2	mm
fit clearance	0.1	mm
inner bottom fillet	0	mm

📦 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 #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 #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 #1533

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀120 mm to 200×60 mm, thickness 3 mm + offset

Download this file in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀120 mm and a rectangular section with internal dimensions 200×60 mm. The wall thickness is 3 mm and the total length is 200 mm. The adapter has an offset of 60 mm along the Z axis.

Parameter	Value	Unit
cylinder outer diameter	120	mm
cylinder inlet length	30	mm
rectangle internal length	200	mm
rectangle internal height	60	mm
rectangle inlet length	30	mm
offset Z	60	mm
offset Y	0	mm
total length	200	mm
thickness	3	mm
chamfer	no chamfer

📦 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 #1801

1 object(s)

- format STL

Tube adapter STL file ⌀ 110–100 mm (Length: 35 mm)

Tube coupler ⌀110 mm to ⌀100 mm in STL format. Final length of this adapter is 35 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 20 mm, the smaller one of 10 mm. The ends are raw.

Parameter	Value	Unit
side A length	20	mm
side A outer diameter	110	mm
side A thickness	3	mm
side B length	10	mm
side B outer diameter	100	mm
side B thickness	3	mm
transition length	5	mm
axis offset	0	mm
ends fillet	no fillet

📦 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 #1458

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 104–50 mm (Length: 85 mm)

Inline tube reducer ⌀104 mm to ⌀50 mm in STL 3D format. Total length of this adapter is 85 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a sleeve length of 30 mm, the smaller one of 25 mm. The two axes of the tubes are off-center by 26.9 mm. The ends are rounded on the inside to facilitate the connection of the two tubes.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	104	mm
side A thickness	2	mm
side B length	25	mm
side B outer diameter	50	mm
side B thickness	2	mm
transition length	30	mm
axis offset	26.9	mm
ends fillet	fillet on th...

📦 Model #1882

1 object(s)

- format STL

Tube adapter STL file ⌀ 80–60 mm (Length: 60 mm)

Tube connector ⌀80 mm to ⌀60 mm in STL 3D format. Final length of this connector is 60 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 20 mm, the smaller one of 20 mm as well. The ends are raw.

Parameter	Value	Unit
side A length	20	mm
side A outer diameter	80	mm
side A thickness	2	mm
side B length	20	mm
side B outer diameter	60	mm
side B thickness	2	mm
transition length	20	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #3774

1 object(s)

- format STL

Container STL 3D file, inner: base Ø60 mm, top Ø65 mm, height 80 mm - wall thickness 3 mm

Download this file of a bowl in STL format. This container can be used for sorting small parts in a workshop or on a desk. The shape is slightly flared, with a inner height of 80 mm, a inner diameter at the top of 65 mm, and a inner diameter at the bottom of 60 mm. The wall is solid. The bowl height is 83 mm.

Parameter	Value	Unit
inner bottom diameter	60	mm
inner top diameter	65	mm
inner height	80	mm
wall thickness	3	mm

📦 Model #4489

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀50 mm to 45×35 mm, thickness 2 mm

3D file in STL format of a round-to-rectangular tube adapter with an outer diameter of ⌀50 mm and a rectangular section with inner dimensions 45×35 mm. The wall thickness is 2 mm and the overall length is 50 mm. A chamfer is present on the outside of the cylindrical end.

Parameter	Value	Unit
cylinder outer diameter	50	mm
cylinder inlet length	10	mm
rectangle internal length	45	mm
rectangle internal height	35	mm
rectangle inlet length	7	mm
offset Z	0	mm
offset Y	0	mm
total length	50	mm
thickness	2	mm
chamfer	chamfer on t...

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.