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

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

Multi-compartment box STL 3D file: 6 compartments of 80×20×20 mm

Rectangular duct adapter STL 3D file 100x20 mm to 80x20 mm – transition: 20 mm

Small parts organizer with 1 drawer 80×80×80 mm STL file, thickness: 3 mm

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

Enclosure with screw-mounted lid STL 3D file: 80×50×35 mm (with ventilation on the lid)

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

Pipe elbow STL file 120° ⌀OD: 40 mm ⌀ID: 34 mm thickness: 3 mm

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

Rectangular-base box with lid STL 3D model – 100×60×20 mm, wall thickness 2 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

Tubing elbow STL file 45° ⌀OD: 76 mm ⌀ID: 70 mm thickness: 3 mm 📦 #3273

1 object(s) - format STL

Latest user-generated 3D models

Hollow tube STL 3D file OD 32.5 mm, ID 30.5 mm, length 100 mm 📦 #12981

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 #2585

3 object(s)

- format STL

Small parts organizer with 20 drawers 30×25×50 mm STL file, thickness: 2 mm

Download this 3D model of a DIY organizer in 3D STL format. This model features 20 compartments, arranged in 4 rows and 5 columns. Specifically, this means 4 rows of 5 compartments. Each compartment has usable dimensions of 30 mm wide, 25 mm high, and 50 mm deep. The wall thickness is 2 mm. The compartments include 1 divider each, which allows up to 2 compartments per compartment and up to 40 compartments in total. The external dimensions of the box are 184.5 x 120 x 56 mm. All the objects in this model are intended to be printable without support.

Parameter	Value	Unit
number of rows	4
number of columns	5
inner drawer depth	50	mm
inner drawer width	30	mm
inner drawer height	25	mm
wall thickness	2	mm
removable divider	one divider ...

📦 Model #906

1 object(s)

- format STL

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

Download this STL file of a U-shaped drawer handle. The overall dimensions are 50×100×10 mm. The handle has a square profile combined with a 90-degree transition. The bores are 6 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	6	mm

📦 Model #3230

1 object(s)

- format STL

O-ring STL file ID 14.6 × CS 1.9 mm

3D file in STL format of rubber ring with dimensions Inner diameter (ID) 14.6 mm × thickness 1.9 mm. Final diameter resulting corresponds to 18.4 mm.

Parameter	Value	Unit
inner diameter (ID)	14.6	mm
cross section (CS)	1.9	mm

📦 Model #3461

2 object(s)

- format STL

Honeycomb grille STL 3D file, center-to-center: 30x30mm, mesh: 3mm - Ø4mm

Download this square honeycomb grid as a STL file. Mounting holes are placed at the four corners (center-to-center 30x30 mm), each with a diameter of Ø4 mm. The overall dimensions reach 38x38 mm, with fine 3 mm cell size for maximum protection. A secondary color rim highlights the outer edge. This grid acts as a protective guard while allowing airflow.

Parameter	Value	Unit
length or center-to-center	30	mm
width or center-to-center	30	mm
mesh size	3	mm
dual color	yes
holes	yes
hole diameter	4	mm

📦 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 #2767

3 object(s)

- format STL

Small parts organizer with 25 drawers 20×25×60 mm STL 3D file, thickness: 2 mm

File of a sorting cabinet with drawers in 3D STL format. This model contains 25 drawers, arranged in 5 rows and 5 columns. In detail, this means 5 rows of 5 drawers. Each drawer measures 20 mm wide, 25 mm high, and 60 mm deep. The wall thickness is 2 mm. The drawers feature 2 dividers each, which allows up to 3 sections per drawer and up to 75 compartments in total. The external dimensions of the structure measure 134.5 x 149.5 x 66 mm. All the objects in this model were designed to be printable without support generation.

Parameter	Value	Unit
number of rows	5
number of columns	5
inner drawer depth	60	mm
inner drawer width	20	mm
inner drawer height	25	mm
wall thickness	2	mm
removable divider	two divider ...

📦 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 #1558

1 object(s)

- format STL

Round air vent STL 3D file ∅ 90 mm, slat angle: 35° with central reinforcement

Design of a round grille for air circulation in STL format. Its insertion diameter is 90 mm. The slats have an angle of 35° and a high thickness of 2.4 mm. A centered vertical reinforcement strengthens the whole structure. This aeration grille features a prominent flange of 18 mm. The total diameter of the model is 126 mm.

Parameter	Value	Unit
male diameter	90	mm
slat angle	35	°
slat thickness	2.4	mm
flange width	18	mm
central reinforcement	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 #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 #2372

1 object(s)

- format STL

Shelf bracket 200×230 mm STL 3D file, thickness 10 mm, hole diameter 5 mm

Download this model of a right-angle bracket with reinforcement in STL 3D format. The dimensions are 200 mm in length, 230 mm in height, 28 mm in width, and 10 mm in thickness. The mounting holes are designed with a diameter of 5 mm. Chamfers are applied to the holes for a cleaner fit of the screws. The reinforcing bar enhances mechanical strength and includes two passages for fastening. This bracket prints without support, placed flat on the build plate.

Parameter	Value	Unit
length	200	mm
height	230	mm
width	28	mm
thickness	10	mm
hole diameter	5	mm
chamfer on the holes	yes

📦 Model #2609

1 object(s)

- format STL

Tubing adapter STL 3D file ⌀ 108–64 mm (Length: 45 mm)

Inline tubing adapter ⌀108 mm to ⌀64 mm in STL format. Length of this coupler is 45 mm. The thickness of the tubes is identical: 8 mm. The larger-diameter tube has a sleeve length of 10 mm, the smaller one of 20 mm. The axes of the tubes are off-center by 20 mm. The ends have no fillet.

Parameter	Value	Unit
side A length	10	mm
side A outer diameter	108	mm
side A thickness	8	mm
side B length	20	mm
side B outer diameter	64	mm
side B thickness	8	mm
transition length	15	mm
axis offset	20	mm
ends fillet	no fillet

📦 Model #3960

2 object(s)

- format STL

Enclosure with screw-mounted lid STL 3D file: 100×70×50 mm

Enclosure model with screwed lid in STL format. The dimensions are 100 mm long by 70 mm wide and 50 mm high. The cover only is 12 mm high. Side thickness is 4 mm. The enclosure does not feature cooling.

Parameter	Value	Unit
length	100	mm
width	70	mm
total height	50	mm
lid height	12	mm
wall thickness	4	mm
screw margin	0	mm
fit clearance	0.1	mm
cooling zone(s)	no cutouts

📦 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 #1195

4 object(s)

- format STL

Color-coded compartment box STL 3D file: 9 compartments of 20×20×20 mm

This multi-compartment box with colored collars design provides 9 slots measuring 20×20×20 mm each. Overall dimensions are 72×72×23 mm.

Parameter	Value	Unit
number of rows	3
number of columns	3
compartment length	20	mm
compartment width	20	mm
compartment height	20	mm
wall thickness	3	mm
compartment fillet (radius)	1	mm
row colors	ABC

📦 Model #4425

1 object(s)

- format STL

Protective grid STL file, center-to-center: 90x64mm, mesh: 3mm - Ø4mm

Download this rectangular grid model in STL format. Mounting holes are placed at the four corners (center-to-center 90x64 mm), each with a diameter of Ø4 mm. The overall dimensions reach 98x72 mm, with extra fine 3 mm cell size for maximum protection. This type of grid serves both protection and ventilation roles.

Parameter	Value	Unit
length or center-to-center	90	mm
width or center-to-center	64	mm
mesh size	3	mm
dual color	no
holes	yes
hole diameter	4	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 #3179

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 50–46 mm (Length: 90 mm)

Diameter adapter ⌀50 mm to ⌀46 mm in STL format. Final length of this coupler is 90 mm. The thickness of the tubes is identical: 2 mm. The larger-diameter tube has a length of 30 mm, the smaller one of 35 mm. The ends are not rounded.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	50	mm
side A thickness	2	mm
side B length	35	mm
side B outer diameter	46	mm
side B thickness	2	mm
transition length	25	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 #3145

1 object(s)

- format STL

Honeycomb grille STL file, center-to-center: 165x105mm, mesh: 5mm - Ø5mm

Download this rectangular protective honeycomb grid file in STL format. Mounting holes are placed at the four corners (center-to-center 165x105 mm), each with a diameter of Ø5 mm. The overall dimensions reach 175x115 mm, with standard 5 mm cell size for balanced airflow and protection. This grid provides both mechanical protection and airflow.

Parameter	Value	Unit
length or center-to-center	165	mm
width or center-to-center	105	mm
mesh size	5	mm
dual color	no
holes	yes
hole diameter	5	mm

📦 Model #2821

2 object(s)

- format STL

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

Download this enclosure with screwed lid in STL format. The dimensions are 100 mm long by 100 mm wide and 20 mm high. The lid measures 10 mm high. Side thickness is 2 mm. This enclosure has cooling area under the base.

Parameter	Value	Unit
length	100	mm
width	100	mm
total height	20	mm
lid height	10	mm
wall thickness	2	mm
screw margin	0	mm
fit clearance	0.1	mm
cooling level	3
cooling zone(s)	cutouts on t...

📦 Model #2177

1 object(s)

- format STL

O'ring STL 3D file ID 48 × CS 1.7 mm

Model of O-ring (torus-shaped seal) with Inner diameter 48 mm by section thickness 1.7 mm. Outer diameter (OD) resulting is 51.4 mm.

Parameter	Value	Unit
inner diameter (ID)	48	mm
cross section (CS)	1.7	mm

📦 Model #978

1 object(s)

- format STL

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

Download this STL 3D model of a basic U-shaped handle. The overall dimensions are 50×140×14 mm. The handle has a square profile and a 90-degree transition. The holes are 6 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	6	mm

📦 Model #1102

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 200–160 mm (Length: 450 mm)

Straight tube fitting ⌀200 mm to ⌀160 mm in STL format. Total length of this coupler is 450 mm. The larger-diameter tube has a thickness of 6 mm and a sleeve length of 200 mm. The smaller-diameter tube has a thickness of 4 mm and a length of 150 mm. The axes of the tubes are offset by 17 mm. The ends are raw.

Parameter	Value	Unit
side A length	200	mm
side A outer diameter	200	mm
side A thickness	6	mm
side B length	150	mm
side B outer diameter	160	mm
side B thickness	4	mm
transition length	100	mm
axis offset	17	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 #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 #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 #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 #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

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.