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

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Tube STL file OD 24 mm, ID 20 mm, length 100 mm

Round air vent STL 3D file ∅ 152 mm, slat angle: 45° with central reinforcement

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

Clip-on tube holder Ø32 mm STL file · Flat head screw Ø4 mm

Shelf bracket 110×110 mm STL file, thickness 8 mm, hole diameter 6 mm

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

Hollow tube STL 3D model OD 60 mm, ID 58 mm, length 100 mm

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

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

Enclosure with screw-mounted lid STL file: 100×100×20 mm (with ventilation on the lid and under the enclosure)

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

View of object #0

Latest user-generated 3D models

Rectangular box with lid STL 3D model – 200×160×40 mm, wall thickness 2 mm 📦 #10775

2 object(s) - format STL

View of object #0

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 #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 #2131

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL 3D file ⌀250 mm to 250×150 mm, thickness 3 mm + offset

File in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀250 mm and a rectangular section with internal dimensions 250×150 mm. The shell thickness is 3 mm and the total length is 165 mm. The adapter has an offset of 15 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	250	mm
cylinder inlet length	50	mm
rectangle internal length	250	mm
rectangle internal height	150	mm
rectangle inlet length	80	mm
offset Z	15	mm
offset Y	0	mm
total length	165	mm
thickness	3	mm
chamfer	chamfers on ...

📦 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 #4417

2 object(s)

- format STL

Enclosure with screw-mounted lid STL 3D file: 120×100×35 mm (with ventilation on the lid and under the enclosure)

Download this enclosure with lid in 3D STL format. The dimensions are 120 mm long by 100 mm wide and 35 mm high. The lid is 10 mm high. Wall thickness is 2 mm. This enclosure has significant cooling area on the lid and under the base.

Parameter	Value	Unit
length	120	mm
width	100	mm
total height	35	mm
lid height	10	mm
wall thickness	2	mm
screw margin	0	mm
fit clearance	0.1	mm
cooling level	8
cooling zone(s)	cutouts on b...

📦 Model #2374

1 object(s)

- format STL

Multi-compartment box STL file: 4 compartments of 96×46×90 mm

This compartment box design features 4 storage spaces measuring 96×46×90mm each. Overall dimensions of the box are 201×101×93mm. A 3mm fillet applied to all compartments make it easier to grasp items stored in the compartments. The dividers are particularly thick.

Parameter	Value	Unit
number of rows	2
number of columns	2
compartment length	96	mm
compartment width	46	mm
compartment height	90	mm
wall thickness	3	mm
compartment fillet (radius)	3	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 #2752

3 object(s)

- format STL

Small parts organizer with 4 drawers 60×20×60 mm STL 3D file, thickness: 2 mm

Download this file of a storage organizer in STL format. This model includes 4 boxes, arranged in 2 rows and 2 columns. Practically speaking, this means 2 rows of 2 boxes. Each box has usable dimensions of 60 mm wide, 20 mm high, and 60 mm deep. The wall thickness is 2 mm. The boxes feature 1 divider each, which allows up to 2 sections per box and up to 8 compartments in total. The overall dimensions of the box measure 135 x 51 x 66 mm. All the objects in this model are intended to be printable without support generation.

Parameter	Value	Unit
number of rows	2
number of columns	2
inner drawer depth	60	mm
inner drawer width	60	mm
inner drawer height	20	mm
wall thickness	2	mm
removable divider	one divider ...

📦 Model #2405

3 object(s)

- format STL

Small parts organizer with 6 drawers 30×30×60 mm STL 3D file, thickness: 3 mm

File of a storage case in 3D STL format. This model contains 6 boxes, arranged in 2 rows and 3 columns. Specifically, this means 2 rows of 3 boxes. Each box comes with an inner space of 30 mm wide, 30 mm high, and 60 mm deep. The wall thickness is 3 mm, which makes the structure sturdy. The boxes feature 2 dividers each, which allows up to 3 compartments per box and up to 18 sections in total. The total size of the box come to 121.5 x 76 x 69 mm. All the objects in this model are intended to be printed without support.

Parameter	Value	Unit
number of rows	2
number of columns	3
inner drawer depth	60	mm
inner drawer width	30	mm
inner drawer height	30	mm
wall thickness	3	mm
removable divider	two divider ...

📦 Model #1786

1 object(s)

- format STL

Round air vent STL file ∅ 120 mm, slat angle: 35°

Model of a round grille for ventilation in STL format. Its insertion diameter is 120 mm. The slats have an angle of 35° and a low thickness of 1.6 mm. This 3D ventilation grille has no flange.

Parameter	Value	Unit
male diameter	120	mm
slat angle	35	°
slat thickness	1.6	mm
flange width	0	mm
central reinforcement	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 #1779

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀100 mm to 180×100.2 mm, thickness 3 mm + offset

Model in STL format of a round-to-rectangular tube adapter with an external diameter of ⌀100 mm and a rectangular section with internal dimensions 180×100.2 mm. The shell thickness is 3 mm and the total length is 240 mm. The adapter has an offset of 60 mm along the Z axis.

Parameter	Value	Unit
cylinder outer diameter	100	mm
cylinder inlet length	50	mm
rectangle internal length	180	mm
rectangle internal height	100.2	mm
rectangle inlet length	50	mm
offset Z	60	mm
offset Y	0	mm
total length	240	mm
thickness	3	mm
chamfer	no chamfer

📦 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 #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 #3133

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 86–75 mm (Length: 160 mm)

Straight tubing adapter ⌀86 mm to ⌀75 mm in STL format. Final length of this junction is 160 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a sleeve length of 70 mm, the smaller one of 60 mm. The ends have no fillet.

Parameter	Value	Unit
side A length	70	mm
side A outer diameter	86	mm
side A thickness	3	mm
side B length	60	mm
side B outer diameter	75	mm
side B thickness	3	mm
transition length	30	mm
axis offset	0	mm
ends fillet	no fillet

📦 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 #1231

1 object(s)

- format STL

Tube adapter STL file ⌀ 68–52 mm (Length: 65 mm)

Straight tube fitting ⌀68 mm to ⌀52 mm in STL 3D format. Total length of this connector is 65 mm. The thickness of the tubes is identical: 4 mm. The larger-diameter tube has a sleeve length of 25 mm, the smaller one of 25 mm as well. The ends have no fillet.

Parameter	Value	Unit
side A length	25	mm
side A outer diameter	68	mm
side A thickness	4	mm
side B length	25	mm
side B outer diameter	52	mm
side B thickness	4	mm
transition length	15	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #1663

1 object(s)

- format STL

Multi-compartment box STL 3D file: 400 compartments of 15×15×25 mm

This compartment box design includes 400 slots measuring 15×15×25mm each. The total dimensions of the box are 342×342×27mm. Fillets of 4mm applied to each compartment provide a better grip stored in the box.

Parameter	Value	Unit
number of rows	20
number of columns	20
compartment length	15	mm
compartment width	15	mm
compartment height	25	mm
wall thickness	2	mm
compartment fillet (radius)	4	mm

📦 Model #2384

1 object(s)

- format STL

Round air vent STL file ∅ 80 mm, slat angle: 45° with central reinforcement

File of a round air vent for ventilation in STL format. Its male diameter is 80 mm. The slats have an angle of 45° and a high thickness of 2 mm. A vertical reinforcement reinforces the whole structure. This 3D vent grille features a prominent flange of 20 mm. The overall diameter of the model is 120 mm.

Parameter	Value	Unit
male diameter	80	mm
slat angle	45	°
slat thickness	2	mm
flange width	20	mm
central reinforcement	yes

📦 Model #3047

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 120 mm - Height: 20 mm, Shell: 5 mm

Download this cylindrical storage box in 3D STL format. Its diameter is 120 mm and its total height is 20 mm. The walls have a thickness of 5 mm.

Parameter	Value	Unit
external diameter	120	mm
total height	20	mm
wall thickness	5	mm
fit clearance	1	mm
inner bottom fillet	0	mm

📦 Model #1935

1 object(s)

- format STL

O-ring STL file ID 43.8 × CS 5.4 mm

3D model of rubber ring with dimensions ID 43.8 mm × section thickness 5.4 mm. Final diameter is therefore 54.6 mm.

Parameter	Value	Unit
inner diameter (ID)	43.8	mm
cross section (CS)	5.4	mm

📦 Model #4299

1 object(s)

- format STL

Tubing adapter STL file ⌀ 70–49 mm (Length: 110 mm)

Tube junction ⌀70 mm to ⌀49 mm in STL 3D format. Final length of this adapter is 110 mm. The larger-diameter tube has a thickness of 5 mm and a sleeve length of 50 mm. The smaller-diameter tube has a thickness of 4 mm and a length of 40 mm. The ends are rounded on the outside to facilitate the connection of the two tubes.

Parameter	Value	Unit
side A length	50	mm
side A outer diameter	70	mm
side A thickness	5	mm
side B length	40	mm
side B outer diameter	49	mm
side B thickness	4	mm
transition length	20	mm
axis offset	0	mm
ends fillet	fillet on th...

📦 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 #6362

2 object(s)

- format STL

Rectangular-base box with lid STL 3D model – 84×45×20 mm, wall thickness 2 mm

Rectangular-base box with a lid provided as a STL 3D file. Overall dimensions are 84 mm long, 45 mm wide, and 20 mm tall. The box features thin 2 mm walls. Interior and exterior edges are rounded. A small clearance is included to ensure a precise fit between the box and the lid. The internal dimensions, excluding rounding, are 80 mm × 41 mm × 16 mm.

Parameter	Value	Unit
length	84	mm
width	45	mm
height	20	mm
wall thikness	2	mm

📦 Model #3745

1 object(s)

- format STL

Pipe elbow STL 3D file 90° ⌀OD: 30 mm ⌀ID: 26 mm thickness: 2 mm

File of an elbow with a 90° angle in STL format. This elbow features an outer diameter of 30 mm and an inner diameter of 26 mm. The tube thickness is therefore 2 mm. The ends feature fillets to make it easier to insert.

Parameter	Value	Unit
outer diameter	30	mm
inner diameter	26	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 #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 #1997

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 80–66 mm (Length: 120 mm)

Straight tube reducer ⌀80 mm to ⌀66 mm in STL format. Total length of this fitting is 120 mm. The larger-diameter tube has a thickness of 3 mm and a sleeve length of 40 mm. The smaller-diameter tube has a thickness of 20 mm and a length of 30 mm. The ends are raw.

Parameter	Value	Unit
side A length	40	mm
side A outer diameter	80	mm
side A thickness	3	mm
side B length	30	mm
side B outer diameter	66	mm
side B thickness	20	mm
transition length	50	mm
axis offset	0	mm
ends fillet	no fillet

📦 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 #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 #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

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.