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

Can’t find the model? Generate it! Trusted by makers worldwide.

To your specs in a few clicks!

Enclosure with screw-mounted lid STL 3D file: 40×40×20 mm (with ventilation on the lid and under the enclosure)

Multi-compartment box STL file: 48 compartments of 20×20×20 mm

Tube adapter STL 3D file ⌀ 100–16 mm (Length: 110 mm)

Round box with lid STL file ⌀ 45 mm - Height: 40 mm, Shell: 2 mm

Tube adapter STL file ⌀ 100–51 mm (Length: 160 mm)

L-bracket 200×200 mm STL file, thickness 5 mm, hole diameter 6 mm

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

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

Multi-tubes fitting 3 tubes STL 3D model – Outer diameter 50 mm, wall thickness 5 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

Tube adapter STL file ⌀ 210–20 mm (Length: 160 mm) 📦 #2156

1 object(s) - format STL

Latest user-generated 3D models

Pipe elbow STL file 90° ⌀OD: 12.5 mm ⌀ID: 10 mm thickness: 1.25 mm 📦 #9287

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 #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 #4138

2 object(s)

- format STL

Small parts organizer with 1 drawer 150×50×100 mm STL file, thickness: 3 mm

Download this 3D model of a multi-drawer box in 3D STL format. This model features 1 box, arranged in 1 rows and 1 columns. Specifically, this means 1 rows of 1 boxes. Each box comes with an inner space of 150 mm wide, 50 mm high, and 100 mm deep. The wall thickness is 3 mm, which makes the structure solid. The total size of the structure are 162.5 x 59.5 x 109 mm. All the objects in this model are intended to be printable without support.

Parameter	Value	Unit
number of rows	1
number of columns	1
inner drawer depth	100	mm
inner drawer width	150	mm
inner drawer height	50	mm
wall thickness	3	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 #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 #2531

1 object(s)

- format STL

Round-to-Rectangular Tube Adapter STL file ⌀158 mm to 210×180 mm, thickness 4 mm

3D file in STL format of a round-to-rectangular tube adapter with an outer diameter of ⌀158 mm and a rectangular section with internal dimensions 210×180 mm. The shell thickness is 4 mm and the overall length is 83 mm. 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	158	mm
cylinder inlet length	35	mm
rectangle internal length	210	mm
rectangle internal height	180	mm
rectangle inlet length	20	mm
offset Z	0	mm
offset Y	0	mm
total length	83	mm
thickness	4	mm
chamfer	chamfers on ...

📦 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 #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 #2186

1 object(s)

- format STL

Tube adapter STL file ⌀ 52–25 mm (Length: 105 mm)

Tube junction ⌀52 mm to ⌀25 mm in STL 3D format. Final length of this junction is 105 mm. The larger-diameter tube has a thickness of 6 mm and a sleeve length of 40 mm. The smaller-diameter tube has a thickness of 3 mm and a length of 50 mm. The ends have a fillet to make tube connection easier.

Parameter	Value	Unit
side A length	40	mm
side A outer diameter	52	mm
side A thickness	6	mm
side B length	50	mm
side B outer diameter	25	mm
side B thickness	3	mm
transition length	15	mm
axis offset	0	mm
ends fillet	fillet on bo...

📦 Model #1880

1 object(s)

- format STL

Pipe elbow STL 3D file 15° ⌀OD: 38.5 mm ⌀ID: 30.5 mm thickness: 4 mm

3D model of a pipe elbow with a 15° angle in STL format. This pipe elbow has an external diameter of 38.5 mm and an internal diameter of 30.5 mm. This results in a tube thickness of 4 mm.

Parameter	Value	Unit
outer diameter	38.5	mm
inner diameter	30.5	mm
angle	15	°
end fillets	no

📦 Model #3822

1 object(s)

- format STL

L-bracket 100×250 mm STL file, thickness 8 mm, hole diameter 6 mm

Download this 3D file of an angle bracket with a reinforcing bar in STL format. The dimensions are 100 mm in length, 250 mm in height, 40 mm in width, and 8 mm in thickness. The drill holes have a diameter of 6 mm. Chamfers are done to the holes to seat the screw heads. The central reinforcement bar reduces bending and provides two passages for fastening. Support generation is not required for printing this bracket, printed flat on the print bed.

Parameter	Value	Unit
length	100	mm
height	250	mm
width	40	mm
thickness	8	mm
hole diameter	6	mm
chamfer on the holes	yes

📦 Model #2544

1 object(s)

- format STL

Tube adapter STL file ⌀ 113–40 mm (Length: 65 mm)

Straight tube reducer ⌀113 mm to ⌀40 mm in STL format. Length of this coupler is 65 mm. The larger-diameter tube has a thickness of 3 mm and a length of 25 mm. The smaller-diameter tube has a thickness of 18 mm and a length of 20 mm. The ends have no fillet.

Parameter	Value	Unit
side A length	25	mm
side A outer diameter	113	mm
side A thickness	3	mm
side B length	20	mm
side B outer diameter	40	mm
side B thickness	18	mm
transition length	20	mm
axis offset	0	mm
ends fillet	no fillet

📦 Model #2797

1 object(s)

- format STL

Tubing adapter STL file ⌀ 97–70 mm (Length: 90 mm)

Tubing adapter ⌀97 mm to ⌀70 mm in STL 3D format. Total length of this coupler is 90 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 are not rounded.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	97	mm
side A thickness	3	mm
side B length	30	mm
side B outer diameter	70	mm
side B thickness	3	mm
transition length	30	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 #1853

1 object(s)

- format STL

Multi-compartment box STL 3D file: 5 compartments of 35×45×15 mm

This multi-compartment box design provides 5 cavities measuring 35×45×15mm each. The total dimensions of the box are 39×237×17mm. Fillets of 10mm applied to each compartment help with item retrieval stored in slots.

Parameter	Value	Unit
number of rows	5
number of columns	1
compartment length	35	mm
compartment width	45	mm
compartment height	15	mm
wall thickness	2	mm
compartment fillet (radius)	10	mm

📦 Model #4218

2 object(s)

- format STL

Round box with lid STL 3D file ⌀ 100 mm - Height: 200 mm, Shell: 3 mm

Get this cylindrical storage box in STL format. Its diameter is 100 mm and its total height is 200 mm. The walls have a thickness of 3 mm. A fillet located at the bottom of the box makes it easier to grab stored objects inside.

Parameter	Value	Unit
external diameter	100	mm
total height	200	mm
wall thickness	3	mm
fit clearance	0.2	mm
inner bottom fillet	1	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 #5689

2 object(s)

- format STL

Rectangular box with lid STL file – 99×74×20 mm, wall thickness 2 mm

STL 3D file for a rectangular box with a lid. The box measures 99 mm in length, 74 mm in width, and 20 mm in height. Wall thickness is 2 mm, giving the box a thin-wall design. The box has rounded edges inside and out. A clearance is provided for an accurate lid-to-box fit. The internal dimensions, excluding rounding, are 95 mm × 70 mm × 16 mm.

Parameter	Value	Unit
length	99	mm
width	74	mm
height	20	mm
wall thikness	2	mm

📦 Model #2564

2 object(s)

- format STL

Small parts organizer with 48 drawers 40×35×100 mm STL 3D file, thickness: 2 mm

Download this model of a DIY organizer in 3D STL format. This model includes 48 compartments, arranged in 8 rows and 6 columns. Practically speaking, this means 8 rows of 6 compartments. Each compartment has usable dimensions of 40 mm wide, 35 mm high, and 100 mm deep. The wall thickness is 2 mm. The external dimensions of the structure are 281 x 318 x 106 mm. All the objects in this model are intended to be printed without support generation.

Parameter	Value	Unit
number of rows	8
number of columns	6
inner drawer depth	100	mm
inner drawer width	40	mm
inner drawer height	35	mm
wall thickness	2	mm
removable divider	none

📦 Model #3747

1 object(s)

- format STL

Round air vent STL file ∅ 150 mm, slat angle: 45° with central reinforcement

3D design of a round grille for ventilation in STL format. Its insertion diameter is 150 mm. The slats have an angle of 45° and a high thickness of 2 mm. A centered vertical reinforcement strengthens the whole structure. This aeration grille features a prominent flange of 20 mm. The full diameter of this model is 190 mm.

Parameter	Value	Unit
male diameter	150	mm
slat angle	45	°
slat thickness	2	mm
flange width	20	mm
central reinforcement	yes

📦 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 #4413

1 object(s)

- format STL

Tube adapter STL 3D file ⌀ 70–34 mm (Length: 80 mm)

Tubing adapter ⌀70 mm to ⌀34 mm in STL 3D format. Total length of this sleeve is 80 mm. The thickness of the tubes is identical: 3 mm. The larger-diameter tube has a length of 30 mm, the smaller one of 30 mm as well. The axes of the tubes are off-center by 3 mm. The ends feature a fillet to facilitate the connection of the two tubes.

Parameter	Value	Unit
side A length	30	mm
side A outer diameter	70	mm
side A thickness	3	mm
side B length	30	mm
side B outer diameter	34	mm
side B thickness	3	mm
transition length	20	mm
axis offset	3	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 #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 #2433

2 object(s)

- format STL

Enclosure with screw-mounted lid STL file: 120×80×52 mm (with ventilation on the lid)

Download this enclosure model with lid in 3D STL format. The dimensions are 120 mm long by 80 mm wide and 52 mm high. The cover only measures 10 mm high. Wall thickness is 4 mm. This enclosure features cooling area on the lid.

Parameter	Value	Unit
length	120	mm
width	80	mm
total height	52	mm
lid height	10	mm
wall thickness	4	mm
screw margin	0	mm
fit clearance	0.2	mm
cooling level	2
cooling zone(s)	cutouts on t...

📦 Model #4326

1 object(s)

- format STL

Hose-shaped reducer STL 3D file 220x100 mm to 185x55 mm – transition: 20 mm

Oval duct adapter in STL 3D file format. The internal cross-section on side A is 220x100 mm, while on side B it is 185x55 mm. A uniform useful length of 5 mm is available on both sleeves. The transition links the two ends over 20 mm, with a total overall length of 30 mm. With 1 mm of thickness, the wall remains flexible and material-efficient. The external edges at the ends are chamfered, which simplifies inserting the adapter into the duct. Side B is offset by 9 mm along the Y axis and 9 mm along the Z axis relative to side A.

Parameter	Value	Unit
side A internal width	220	mm
side A internal height	100	mm
sleeve length on side A	5	mm
side B internal width	185	mm
side B internal height	55	mm
sleeve length on side B	5	mm
thickness	1	mm
transition length	20	mm
Y offset	9	mm
Z offset	9	mm
end chamfers	outside

📦 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 #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 #818

1 object(s)

- format STL

U-shaped handle STL file 35×100×14 mm (Center-to-center 86 mm)

Download this STL file of a simple U-shaped drawer handle. The external dimensions are 35×100×14 mm. This handle features a square cross-section and a right-angled transition. A fillet along the edges produces a better tactile feel. The bores are 5 mm diameter with a center-to-center distance of 86 mm.

Parameter	Value	Unit
width	35	mm
length	100	mm
thickness	14	mm
shape (0:square,1:circle)	0
transition (0:right,1:rounded)	0
fillet radius	1	mm
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.