NX CAD 3D Modelling with Extrude, Revolve, Fillet and Shell — Step-by-Step Tutorial (Updated June 2026) (Updated June 2026)

If you've gone through the NX CAD sketching fundamentals, you know how to create precise 2D profiles — constrained, dimensioned, ready to become 3D shapes. Here's where this tutorial picks up: turning those 2D sketches into solid 3D models using NX's most essential feature commands. The good news is that 80% of the mechanical parts you'll ever model in real industry work — brackets, shafts, flanges, housings, covers — can be created using just three commands: Extrude, Revolve, and a handful of feature operations (chamfer, fillet, shell, hole). Master these and you're already productive. Siemens NX is the standard design tool at companies like Tata Motors, Mahindra, Bajaj Auto Akurdi, and Endurance Technologies across Pune. When recruiters ask for NX CAD experience, what they usually mean is: can you create complex 3D parts, generate manufacturing drawings, and understand how design intent is captured in features? This tutorial addresses the first half of that — solid 3D feature modelling. What most people don't realize is that NX handles 3D features differently from SolidWorks or CATIA. The underlying concept is the same (feature-based parametric modelling), but the workflow has NX-specific steps and terminology. We walk through the entire process with clear, step-by-step instructions so you're not just watching — you're modelling along.

Understanding NX CAD Feature-Based Modelling — The Core Concept

NX uses a feature-based, history-based modelling approach. Every command you run — Extrude, Fillet, Hole — creates a feature that's recorded in the Part Navigator (the history tree). You can go back to any feature in the tree, edit its parameters, and NX will recompute the model. This is called parametric modelling and it's what makes professional CAD software powerful for real design work. The Part Navigator in NX shows your model as a list of operations: Sketch(1) → Extrude(1) → Fillet(1) → Hole(1). Clicking on any item and choosing Edit Parameters lets you change that feature. This is the approach used by Mahindra's product development teams and by auto component suppliers like Bharat Forge and Endurance Technologies when they iterate on designs during development cycles.

The Extrude Command: Your Most Used 3D Tool in Siemens NX

The Extrude command takes any closed 2D sketch and pulls it out in a defined direction to create a 3D solid body. To run it in NX: go to Insert → Design Feature → Extrude (or press X as a shortcut in most NX installations). Select your sketch profile. Set the distance (the depth of the extrusion). Key options: Symmetric (extrude equal distances both directions), Two Limits (extrude different distances each way), and Through All (extrude until it hits another face — useful for cut operations). You can also use Extrude as a Boolean operation: Subtract to cut material from an existing solid, Unite to add to it, or Intersect to keep only the overlapping volume. A mechanical flange, a housing wall, a bracket rib — all start with Extrude. This is genuinely the most important NX command for 80% of mechanical part modelling.

Revolve: Modelling Shafts, Pulleys and Rotational Parts Fast

Revolve creates 3D solids by spinning a 2D profile around an axis. Think shafts, pulleys, valve bodies, wheel hubs, nozzle tips — any part with rotational symmetry. To use Revolve in NX: Insert → Design Feature → Revolve. Select your 2D profile (a sketch or a set of curves). Define the axis of revolution — you can use a datum axis, a straight edge, or draw a line in the sketch that will serve as the rotation centre. Set the angle — 360° for a full solid, less for a partial revolution. The profile you draw represents the cross-section that gets rotated. For a shaft with steps (different diameters along the length), you draw the stepped cross-section in the sketch, then revolve it 360°. Understanding Revolve unlocks a huge range of mechanical parts that would take much longer to model using only Extrude.

NX Feature	Primary Use	NX Menu Path
Extrude	Pull 2D sketch into 3D solid; cut or add material	Insert → Design Feature → Extrude (X)
Revolve	Spin a 2D profile around an axis for rotational parts	Insert → Design Feature → Revolve
Chamfer	Flat bevel cut at an edge; reduces sharp corners	Insert → Detail Feature → Chamfer
Fillet (Edge Blend)	Smooth curved radius at edge; eliminates stress concentration	Insert → Detail Feature → Edge Blend
Shell	Hollow out a solid; creates enclosures with consistent wall thickness	Insert → Offset/Scale → Shell
Hole	Standard/threaded holes with correct tolerances and sizing	Insert → Design Feature → Hole

Chamfer and Fillet: Edge Finishing That Matters for Manufacturing

Once you have a 3D solid, chamfers and fillets clean up the edges for both manufacturing and aesthetics. Chamfer cuts a flat bevel at an edge — typically at a 45° angle, though NX lets you set different angles and offset distances. Fillets add a smooth curved radius at an edge. In manufacturing, sharp internal corners create stress concentrations that can lead to fatigue cracks — fillets eliminate this risk. Sharp external edges can create machining burrs and assembly problems — chamfers handle that. In NX: Insert → Detail Feature → Chamfer or Fillet. Select the edges you want to modify, set the value, and confirm. Tip for beginners: apply fillets and chamfers late in the modelling process — adding them early can cause problems when you later edit the underlying geometry. Industry standard at companies like Tata Motors and Bosch Pune is to define standard fillet/chamfer values in a design template so all parts follow the same conventions.

Shell Feature: Creating Hollow Enclosures and Covers in NX

Shell is one of the most useful NX features for product designers. It takes a solid body and hollows it out, leaving walls of a defined thickness. The result looks like a box or cover — closed on most sides, open on the face(s) you designate. To use Shell in NX: Insert → Offset/Scale → Shell. Select the solid body. Set the wall thickness. Select the face(s) to open (remove) — this becomes the open side of the shell. Shell is used for plastic housings, electrical enclosure covers, pump bodies, gear boxes — anywhere you need a hollow part with consistent wall thickness. In injection moulding design (common in automotive plastics), uniform wall thickness is critical to prevent sink marks and warpage. Shell enforces this automatically. If you need different wall thicknesses on different faces, NX lets you set alternate thickness values for individual faces.

The Hole Command: Threaded and Non-Threaded Holes Done Right

The Hole feature in NX creates holes correctly — with standard sizing, tolerances, and optional threading that matches manufacturing standards. Don't just use Extrude to cut a cylinder for a hole — use the proper Hole command, which captures the engineering intent. In NX: Insert → Design Feature → Hole. Set the hole type: Simple (plain through-hole or blind), Counterbore (wider recessed area for bolt heads), Countersink (conical entry for flathead screws), or Threaded (NX includes standard M-series metric and UNC inch thread tables). Set the diameter and depth. The Hole command also supports series hole patterns — place a hole, then pattern it around a bolt circle or along a linear array. This is how real flange bolt patterns are created in NX.

Practical Exercise: Model a Simple Bracket Using These Commands

Let's put these commands together with a practical exercise. Create a simple L-bracket: Step 1 — create a new part file. Step 2 — start a sketch on the XZ plane. Step 3 — draw an L-shape profile (two rectangles joined at a corner). Step 4 — add dimensions (80mm tall, 60mm wide, 5mm thick). Step 5 — Extrude the L-profile by 40mm (the bracket depth). Step 6 — Fillet the internal corner at 3mm radius. Step 7 — Chamfer the outer edges at 1mm. Step 8 — add 4mm diameter mounting holes using the Hole command at each end of the bracket. That's your first real mechanical component, modelled correctly. Save it — you'll use it when building assemblies in the next lesson. If you want in-person NX CAD training with structured exercises and industry projects, visit ABC Trainings at Wagholi, Hadapsar, or Sambhajinagar. Call +91 7039169629 or WhatsApp 7774002496.

Engineering students learning NX CAD in Maharashtra can claim the Chief Minister Yuva Kaushalya Parishram Yojana (CMYKPY) stipend of ₹6,000–10,000/month during their training period at an approved institution. ABC Trainings supports eligible students with the application process — enquire at any of our centres in Wagholi, Hadapsar, or Sambhajinagar.

FAQs

What is the difference between Extrude and Revolve in NX CAD?

Extrude pulls a 2D sketch in a straight linear direction to create a 3D solid — like pushing clay through a shaped die. It's used for prismatic shapes: brackets, plates, blocks, ribs. Revolve spins a 2D profile around an axis to create rotational solids — like a lathe. It's used for cylindrical shapes: shafts, pulleys, wheel hubs, valve bodies. In practice, most mechanical parts use a combination of both: you might Revolve a shaft, then Extrude a keyway slot cut into it. Both commands also support Boolean operations — Unite (add material), Subtract (remove material), and Intersect.

How do I edit a feature I already applied in NX CAD?

In NX, every feature you create is stored in the Part Navigator (the history tree on the left side). To edit any feature: find it in the Part Navigator, right-click on it, and choose Edit Parameters (or double-click it). This reopens the feature dialog with all your original settings. Change whatever you need — distance, angle, profile dimensions — and click OK. NX will recompute the model from that point in the history. This parametric editing workflow is what makes NX so powerful for design iteration.

When should I apply fillets and chamfers in my NX modelling workflow?

Apply fillets and chamfers towards the end of your modelling workflow — after the main geometry (extrudes, revolves, holes) is complete and correct. Fillets and chamfers attach to specific edges. If you later edit an earlier feature and that edge changes or disappears, the fillet/chamfer may fail or produce unexpected results. The safe order is: sketch → main features (extrude/revolve) → holes and cuts → patterns and mirrors → fillets → chamfers. In NX, if a fillet fails after an upstream edit, you'll see an error marker in the Part Navigator — double-click it to diagnose and repair.

Which NX CAD version is used in Indian automotive companies like Tata Motors and Bajaj Auto?

Most Indian automotive OEMs and Tier-1 suppliers standardise on NX 11, NX 12, NX 1899, or the newer NX 2306/2312 releases. Tata Motors, Mahindra, and Bajaj Auto predominantly use NX in the NX 11 through NX 1953 range as of 2025–2026. KPIT Technologies and Endurance Technologies work across multiple versions depending on their client OEM. At ABC Trainings, we train on NX versions currently required by Pune automotive employers — ask our counsellors which version is current when you enrol.