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 duct adapter STL 3D file 200x90 mm to 80x80 mm – transition: 60 mm

Pipe elbow STL file 120° ⌀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

Round air vent STL file ∅ 150 mm, slat angle: 10° with central reinforcement

Protective grid STL file, center-to-center: 105x105mm, mesh: 4mm - Ø4mm

Pipe clip holder Ø50 mm STL file · Countersunk screw Ø5 mm

Box STL 3D file with dimensions 50×50×60 mm

Small parts organizer with 6 drawers 40×15×30 mm STL 3D file, thickness: 2 mm

Tube adapter STL file ⌀ 50–40 mm (Length: 45 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

Rectangular prism STL 3D file 100×77×22 mm 📦 #752

1 object(s) - format STL

Latest user-generated 3D models

Round air vent STL file ∅ 100 mm, slat angle: 30° with central reinforcement 📦 #12717

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 #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 #1459

1 object(s)

- format STL

O-ring STL file ID 12.2 × CS 2.2 mm

3D model of O-ring (torus-shaped seal) with dimensions Internal diameter 12.2 mm by section thickness 2.2 mm. The outer diameter is therefore 16.6 mm.

Parameter	Value	Unit
inner diameter (ID)	12.2	mm
cross section (CS)	2.2	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 #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 #1171

1 object(s)

- format STL

O-ring STL file ID 100 × CS 5 mm

Model of rubber ring with dimensions ID (inner diameter) 100 mm / thickness 5 mm. Outer diameter (OD, for outer diameter) resulting is 110 mm.

Parameter	Value	Unit
inner diameter (ID)	100	mm
cross section (CS)	5	mm

📦 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 #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 #2457

1 object(s)

- format STL

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

Download this file of a pot in STL 3D format. This container can be used for sorting small parts in a workshop or on a desk. The sides are vertical, providing a constant internal volume, with a internal height of 40 mm and an identical internal diameter at the top and bottom of 40 mm. The total height is 42 mm.

Parameter	Value	Unit
inner bottom diameter	40	mm
inner top diameter	40	mm
inner height	40	mm
wall thickness	2	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 #1303

2 object(s)

- format STL

Enclosure with screw-mounted lid STL file: 174×120×56 mm (with ventilation on the lid)

Enclosure model with screwed lid in 3D STL format. The dimensions are 174 mm long by 120 mm wide and 56 mm high. The cover only measures 10 mm high. Wall thickness is 3 mm. This enclosure features strong cooling area on the lid.

Parameter	Value	Unit
length	174	mm
width	120	mm
total height	56	mm
lid height	10	mm
wall thickness	3	mm
screw margin	0	mm
fit clearance	0.2	mm
cooling level	5
cooling zone(s)	cutouts on t...

📦 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 #2054

1 object(s)

- format STL

Round air vent STL 3D file ∅ 71 mm, slat angle: 40° with central reinforcement

Model of a round air vent for ventilation in STL format. Its insertion diameter measures 71 mm. The slats have an angle of 40° and a high thickness of 2.4 mm. A centered vertical reinforcement reinforces the slats. This 3D aeration grille has a thin flange of 4 mm. The full diameter of the model is 79 mm.

Parameter	Value	Unit
male diameter	71	mm
slat angle	40	°
slat thickness	2.4	mm
flange width	4	mm
central reinforcement	yes

📦 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 #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 #2994

1 object(s)

- format STL

Tubing adapter STL 3D file ⌀ 60–51 mm (Length: 55 mm)

Straight sleeve ⌀60 mm to ⌀51 mm in STL format. Final length of this sleeve is 55 mm. The thickness of the tubes is identical: 2.5 mm. The larger-diameter tube has a sleeve length of 25 mm, the smaller one of 25 mm as well. The ends feature a fillet.

Parameter	Value	Unit
side A length	25	mm
side A outer diameter	60	mm
side A thickness	2.5	mm
side B length	25	mm
side B outer diameter	51	mm
side B thickness	2.5	mm
transition length	5	mm
axis offset	0	mm
ends fillet	fillet on bo...

📦 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 #4243

2 object(s)

- format STL

Small parts organizer with 400 drawers 148×150×148 mm STL 3D file, thickness: 4 mm

Download this 3D model of a sorting cabinet with drawers in STL format. This model features 400 drawers, arranged in 20 rows and 20 columns. Practically speaking, this means 20 rows of 20 drawers. Each drawer comes with an inner space of 148 mm wide, 150 mm high, and 148 mm deep. The wall thickness is 4 mm, which makes the structure very sturdy. The total size of the structure come to 3214 x 3174 x 160 mm. All the objects in this model are intended to be printable without support.

Parameter	Value	Unit
number of rows	20
number of columns	20
inner drawer depth	148	mm
inner drawer width	148	mm
inner drawer height	150	mm
wall thickness	4	mm
removable divider	none

📦 Model #1577

1 object(s)

- format STL

Round air vent STL 3D file ∅ 50 mm, slat angle: 10° with central reinforcement

Model of a round vent cover for ventilation in STL format. Its male diameter measures 50 mm. The slats have a slight angle of 10° and a high thickness of 2 mm. A central reinforcement secures the slats. This aeration grille has a flange of 10 mm. The total diameter of the model is 70 mm.

Parameter	Value	Unit
male diameter	50	mm
slat angle	10	°
slat thickness	2	mm
flange width	10	mm
central reinforcement	yes

📦 Model #3642

1 object(s)

- format STL

Honeycomb grid STL 3D file, center-to-center: 300x200mm, mesh: 10mm - Ø4mm

Download this 3D rectangular grid as a STL file. Mounting holes are placed at the four corners (center-to-center 300x200 mm), each with a diameter of Ø4 mm. The overall dimensions reach 308x208 mm, with very open 10 mm cell size for peak ventilation. This grid provides both mechanical protection and airflow.

Parameter	Value	Unit
length or center-to-center	300	mm
width or center-to-center	200	mm
mesh size	10	mm
dual color	no
holes	yes
hole diameter	4	mm

📦 Model #976

1 object(s)

- format STL

U-shaped handle STL 3D file 50×140×14 mm (Center-to-center 126 mm)

Download this STL 3D file of a simple U-shaped drawer handle. The external dimensions are 50×140×14 mm. This handle features a square cross-section and a straight transition. The bores are 4 mm diameter and have a 126 mm center-to-center distance.

Parameter	Value	Unit
width	50	mm
length	140	mm
thickness	14	mm
shape (0:square,1:circle)	0
transition (0:right,1:rounded)	0
fillet radius	0	mm
hole diameter	4	mm

📦 Model #837

1 object(s)

- format STL

U-shaped handle STL file 35×100×20 mm (Center-to-center 80 mm)

Download this model of a simple U-shaped furniture handle. The overall dimensions are 35×100×20 mm. The handle has a square profile combined with a straight transition. A fillet along the edges allows for a more pleasant grip. The mounting holes are 6 mm diameter with a center-to-center distance of 80 mm.

Parameter	Value	Unit
width	35	mm
length	100	mm
thickness	20	mm
shape (0:square,1:circle)	0
transition (0:right,1:rounded)	0
fillet radius	1	mm
hole diameter	6	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 #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 #3805

2 object(s)

- format STL

Enclosure with screw-mounted lid STL 3D file: 100×80×30 mm

Enclosure model with screwed lid in STL format. The dimensions are 100 mm long by 80 mm wide and 30 mm high. The cover is 10 mm high. Wall thickness is 3 mm. The enclosure does not feature cooling.

Parameter	Value	Unit
length	100	mm
width	80	mm
total height	30	mm
lid height	10	mm
wall thickness	3	mm
screw margin	0.1	mm
fit clearance	0.1	mm
cooling zone(s)	no cutouts

📦 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 #1392

1 object(s)

- format STL

Pipe elbow STL 3D file 170° ⌀OD: 40 mm ⌀ID: 36 mm thickness: 2 mm

File of an elbow with a 170° angle in STL format. This elbow features an external diameter of 40 mm and an internal diameter of 36 mm. The tube thickness is therefore 2 mm. End fillets make it easier to insert.

Parameter	Value	Unit
outer diameter	40	mm
inner diameter	36	mm
angle	170	°
end fillets	yes

📦 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 #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 #3843

1 object(s)

- format STL

Round air vent STL file ∅ 100 mm, slat angle: 33° with central reinforcement

3D model of a round vent cover for air circulation in STL format. Its insertion diameter is 100 mm. The slats have an angle of 33° and a high thickness of 1.8 mm. A vertical reinforcement strengthens the slats. This vent cover features a thin flange of 5 mm. The total diameter of the model is 110 mm.

Parameter	Value	Unit
male diameter	100	mm
slat angle	33	°
slat thickness	1.8	mm
flange width	5	mm
central reinforcement	yes

📦 Model #2597

1 object(s)

- format STL

Multi-compartment box STL file: 20 compartments of 30×30×20 mm

This sectioned box design includes 20 sections measuring 30×30×20mm each. Overall dimensions are 162×130×22mm. A 2mm fillet applied to each compartment provide a better grip stored in the compartments.

Parameter	Value	Unit
number of rows	4
number of columns	5
compartment length	30	mm
compartment width	30	mm
compartment height	20	mm
wall thickness	2	mm
compartment fillet (radius)	2	mm

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.