Engineering CAD Design Library

Browse quality-checked 3D CAD models for engineering, product design, prototyping and manufacturing. Preview models online and download files in STEP, STP, IGES, STL, OBJ, PLY, DWG, DXF and more.

All 3D Printing Aerospace Architecture Automotive Aviation Chemical Construction Electrical Energy And Power Industrial Design Jewellery Machine design Marine Medical Robotics

Browse by part & function

The axis engineers actually search on — pick a part type to filter the catalog.

See all parts →

Mechanical Linkage

32 parts

Surface Mount Device

32 parts

Mechanical Coupling

32 parts

Common Mode Choke

33 parts

Rotational Motion

33 parts

Turbine

34 parts

Automotive Component

34 parts

Structural Analysis

34 parts

Chemical Plant Design

36 parts

Planetary Gear

36 parts

Biomechanics

36 parts

Cooling System

36 parts

Gear Mechanism

36 parts

Motion Control

37 parts

Linear Motion

37 parts

Electromechanical

37 parts

Mechanical Joint

40 parts

Bracket

41 parts

Transformer

42 parts

Ergonomics

43 parts

Ring

43 parts

Automotive Engineering

43 parts

Structural Engineering

43 parts

Power Electronics

46 parts

Jewellery Design

46 parts

Airfoil

47 parts

Pcb

47 parts

Aerospace Engineering

49 parts

Robot Design

50 parts

Cnc

53 parts

Bearing

54 parts

Gearbox

54 parts

Renewable Energy

54 parts

Conveyor System

55 parts

Enclosure

55 parts

3D Printable

57 parts

Furniture Design

57 parts

Heat Exchanger

57 parts

Power Supply

58 parts

Precision Component

60 parts

Sheet Metal

61 parts

Structural Support

62 parts

Power Transmission

62 parts

Ergonomic Design

64 parts

Actuator

64 parts

Inductor

66 parts

Propeller

67 parts

Brushless Motor

68 parts

Fluid Control

70 parts

Drone

70 parts

Medical Equipment

72 parts

Process Engineering

72 parts

Robotic Arm

72 parts

Fastener

72 parts

Hydrodynamics

74 parts

Structural Design

74 parts

Energy Storage

78 parts

Electronic Component

85 parts

Servo Motor

88 parts

Product Design

89 parts

Fluid Dynamics

99 parts

Standard Part

104 parts

Electric Motor

112 parts

Industrial Machinery

113 parts

Thermal Management

116 parts

Engine Component

123 parts

Mechanical Transmission

135 parts

Marine Engineering

138 parts

Manufacturing Preparation

142 parts

Mechanical Engineering

143 parts

Standard Mechanical Component

145 parts

Connector

145 parts

Medical Device

148 parts

Industrial Design

152 parts

Electrical Connector

154 parts

Power Distribution

163 parts

Industrial Automation

169 parts

Industrial Component

170 parts

Material Handling

179 parts

Automation

206 parts

Electrical Component

214 parts

Precision Engineering

232 parts

Industrial Equipment

240 parts

Mechanical Integration

310 parts

Manufacturing

315 parts

Energy Systems

367 parts

Mechanical Systems

401 parts

Engineering Design

475 parts

Energy Distribution

481 parts

Design Prototyping

519 parts

Electrical Design

522 parts

Equipment Layout

522 parts

Power System Integration

549 parts

Mechanical Assembly

719 parts

Prototype

766 parts

Manufacturing Simulation

886 parts

Engineering Assembly

892 parts

Mechanical Design

1390 parts

System Integration

1440 parts

Mechanical Component

2465 parts

Build kits

Curated systems with verified mating parts — download the whole assembly at once.

All collections →

CONSUMER ELECTRONICS

iPhone Accessory & Case Design Kit

A practical iPhone accessory cluster for designing cases, charging stands, holders and fit-checking around real phone geometry.

6 partspairs verified

DRONES / UAV

250 mm FPV Drone Build Kit

A complete FPV quad build cluster covering frame, propulsion, camera, control electronics, battery housing and mounting hardware.

7 partspairs verified

MOTION CONTROL

NEMA 17 Motion / Linear Actuator Kit

A motion-control cluster around a NEMA 17 stepper, bracket, coupler, GT2 belt, pulley, bearing and driver.

5 partspairs verified

10,000+ models2D drawings

Sort by:

Free

ENERGY AND POWER · TURBINE NOZZLE SHROUD

Turbine Nozzle Shroud for Hot Gas Flow Guidance

.STEP

Open STEP file viewer Convert STEP to STL

0 downloads

Preview

Free

AEROSPACE · ENGINE COMBUSTION CHAMBER

Complete Engine Combustion Chamber Assembly with Air Cooling Design

.STEP

Open STEP file viewer Convert STEP to STL

0 downloads

Preview

Free

MACHINE DESIGN · PLANETARY GEARBOX

Neugart PLPE090-020-SSSA3AE-Z19 Planetary Gearbox Reducer

.STEP

Open STEP file viewer Convert STEP to STL

0 downloads

Preview

Free

ELECTRICAL · MEMS OSCILLATOR

SiTime Emerald Series MEMS Oscillators - Programmable Oven and Digitally Controlled OCXOs

.STEP

Open STEP file viewer Convert STEP to STL

0 downloads

Preview

Need a CAD file that is not in the library?

Share your requirement and Marathon OS will match you with a vetted CAD designer for production-ready CAD files, edits and manufacturing documentation.

Get it Built

500+Projects Done

24 hrResponse

15+CAD Tools

Free