Comprehensive Catalog Reference

LEGO Parts Guide

Explore the official classification of LEGO building elements. Learn geometric ratios, stud rules, part categories, and instantly browse active catalog pieces.

Master Category Architecture

8 Core Classes
LEGO Parts Guide Hierarchy
│
├── 🧱 Bricks (Standard 1x & 2x blocks, heights & anti-stud tubes)
├── 🛹 Plates (1/3 height layer connectors & baseplates)
├── 🟦 Tiles (Smooth studless display surfaces & sliding tracks)
├── 📐 Slopes (33°, 45°, 75°, inverted & curved aerodynamic faces)
├── ⚙️ Technic (Liftarms, cross axles, pin connectors & gearboxes)
├── 🧑‍🚀 Minifigure Parts (Heads, torsos, legs, hair & props)
├── ⚪ Round & Cylinders (1x1 studs, cylinders, cones & domes)
└── ✨ Specialty & SNOT (Headlights, brackets, hinges & ball joints)
Filter Guide:
🧱
Category Reference

Standard Bricks

Solid 1x and 2x building blocks with stud tops and hollow anti-stud tubes.

Key Technical Characteristics

  • •Height ratio: 3 plates = 1 standard brick height (9.6 mm without studs).
  • •Features internal anti-stud tubes providing clutch power when connected.
  • •Core sizes include 2x4 (Part 3001), 2x2 (Part 3003), 1x2 (Part 3004), and 1x1 (Part 3005).

Common Primary Uses in MOCs

Load-bearing walls, structural frameworks, foundation building, and general LEGO construction.

Famous Design IDs in Category:
🛹
Category Reference

Structural Plates

Shallow 1/3 height connection plates essential for precise step adjustments.

Key Technical Characteristics

  • •Exactly 1/3 the height of a standard brick (3.2 mm thickness).
  • •Enables micro-stepping and SNOT (Studs Not On Top) techniques when layered.
  • •Includes essential sizes like 2x4 (3020), 2x2 (3022), 1x2 (3023), and 1x4 (3710).

Common Primary Uses in MOCs

Baseplate extensions, vehicle floors, thin layering, and structural tie-ins.

Famous Design IDs in Category:
🟦
Category Reference

Smooth Tiles

Studless top plates providing smooth finished surfaces and sliding tracks.

Key Technical Characteristics

  • •Features a smooth top surface without studs, typically with a slight bottom groove.
  • •1x1, 1x2, 2x2, 2x4, and 1x8 dimensions are standard in modular buildings.
  • •Specialty variants include round tiles (98138) and modified grill tiles (2412).

Common Primary Uses in MOCs

Tiled floors, vehicle hood panels, display trim, sliding mechanisms, and printed road signs.

Famous Design IDs in Category:
📐
Category Reference

Angled Slopes

Angled face bricks (33°, 45°, 75°, inverted, and curved) for aerodynamics.

Key Technical Characteristics

  • •Inverted slopes (e.g. 3665) have angled faces underneath for overhangs.
  • •Curved slopes (e.g. 15068 2x2 curved) provide smooth organic contours without studs.
  • •Standard pitch angles include 45° (3039) and 33° (3040).

Common Primary Uses in MOCs

Roofing, aircraft noses, vehicle windshield transitions, and sculptured MOC details.

Famous Design IDs in Category:
⚙️
Category Reference

Technic Parts & Beams

Studless liftarms, cross axles, pin connectors, and meshable gears.

Key Technical Characteristics

  • •Includes studless liftarms, perforated bricks, cross-axle pins, and bevel gears.
  • •Designed around standard 8mm hole pitch grid system for mechanical power transfer.
  • •Friction pins (black/blue) hold rigid connections; smooth pins (light gray) allow rotation.

Common Primary Uses in MOCs

Gearboxes, steering linkages, robotics, suspension arms, and heavy structural frames.

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🧑‍🚀
Category Reference

Minifigure Parts

Headgears, heads, torsos with arms/hands, legs, and character accessories.

Key Technical Characteristics

  • •Standard minifigure height is 40mm (approx 4 bricks high).
  • •Torsos feature 3.18mm neck studs and flexible arm/wrist socket connectors.
  • •Heads feature top stud attachment for hair/helmets and dual-printed expression faces.

Common Primary Uses in MOCs

Character customization, storytelling, dioramas, and collector minifig display.

Famous Design IDs in Category:
⚪
Category Reference

Round & Cylinder Pieces

Round 1x1 studs, 2x2 cylinders, cones, and dome caps for rounded shapes.

Key Technical Characteristics

  • •1x1 round plates/studs (4073) are ubiquitous accent details.
  • •2x2 round bricks (3941) have hollow centers compatible with Technic axles.
  • •Cones (3942) taper smoothly from 2x2 to 1x1 stud dimension.

Common Primary Uses in MOCs

Columns, lights, engines, tree trunks, barrels, rockets, and circular geometry.

Famous Design IDs in Category:
✨
Category Reference

Specialty & SNOT Bricks

Modified bricks with side studs, hinges, clips, brackets, and ball joints.

Key Technical Characteristics

  • •Headlight brick (4070 / Erling brick) offsets stud depth by 0.5mm for recessed details.
  • •Brackets (e.g. 99207 1x2-2x2) invert stud direction vertically or horizontally.
  • •Mixel ball joints (14704 / 14417) provide smooth 360-degree articulation.

Common Primary Uses in MOCs

Advanced SNOT techniques, articulated creature limbs, steering, and wall cladding.

Famous Design IDs in Category:

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