Materials Guide
We Machine Almost Anything
Metals, engineering plastics, and exotic superalloys — if it can be machined to tight tolerances, we have the programmes, tooling, and experience to do it. Use this guide to choose the right material for your application.
How to Choose the Right Material
Four questions to ask before specifying your material.
What loads will the part see?
Static loads → 6061 often sufficient. Dynamic/impact → 7075 or steel. Extreme loads at high temp → Inconel or titanium.
What is the operating environment?
Dry indoor use → mild steel fine. Seawater exposure → 316L or titanium. Medical/food contact → 316L, titanium, or PEEK.
How much does weight matter?
Weight-critical → aluminium or titanium. Weight not critical → steel is cheaper and stronger. Ultra-light → PEEK or CFRP.
What finishing is required?
Anodising → aluminium only. Passivation → stainless. Paint/powder coat → steel. No finish needed → stainless or PEEK.
Full Materials List
Machinability & Specifications
Machinability rating: ●●●●● = easiest (fastest, cheapest per piece). ● = hardest (specialised tooling, slower, higher cost).
Aluminium
Aluminium 6061-T6
The go-to alloy for most general CNC applications. Excellent strength-to-weight ratio, good corrosion resistance, and takes anodising beautifully. Easy to machine at high speeds with excellent surface finish.
Aluminium 7075-T6
The strongest common aluminium alloy. Used wherever 6061 isn't strong enough. Slightly harder to machine than 6061 but still excellent. Cannot be welded easily — typically fastened or bonded.
Stainless Steel
Stainless Steel 304
The most widely used stainless grade. Good corrosion resistance in most environments except chloride-rich (seawater). Work-hardens during cutting — requires sharp tooling and correct feeds/speeds.
Stainless Steel 316L
The addition of molybdenum gives 316L superior chloride corrosion resistance over 304. The 'L' grade (low carbon) prevents carbide precipitation during welding. Standard choice for medical and marine applications.
Titanium
Titanium Grade 5 (Ti-6Al-4V)
The most-used titanium alloy. Excellent specific strength, fully biocompatible (ASTM F136 implant grade available), and immune to salt water corrosion. Difficult to machine — requires specialised tooling, slow speeds, heavy coolant, and careful fixturing. Our programmes are proven.
Nickel Superalloy
Inconel 718
One of the most difficult materials to machine — work-hardens aggressively, generates extreme cutting heat, and wears tooling rapidly. We machine Inconel daily with proven feeds, speeds, and tooling strategies. Don't attempt this on a standard CNC centre without experience.
Steel
Mild Steel (1018 / 1045)
The workhorse of the engineering world. Cheap, machines cleanly, welds and heat-treats well. No inherent corrosion resistance — typically painted, powder-coated, or zinc-plated after machining. 1018 is better for cold-working; 1045 gives higher strength.
Tool Steel D2 / H13
D2 is a high-chrome cold-work tool steel used for press tooling and dies. H13 is a hot-work grade used for die casting dies and injection moulds. Both are typically rough-machined in soft state, then hardened and finish-ground to final dimensions.
Copper Alloy
Brass (C360 / Naval)
C360 (free-machining brass) has the highest machinability rating of any common metal — machines at very high speeds with excellent surface finish and minimal tool wear. Naval brass adds tin for improved seawater corrosion resistance.
Copper (C110)
Chosen for its electrical and thermal conductivity — both the highest of any commonly machined metal. Machines well but is soft and can smear at excessive speeds. Used wherever conductivity matters more than strength.
Engineering Plastic
PEEK
The top-tier engineering thermoplastic. Retains mechanical properties to 250°C, fully biocompatible (USP Class VI), resistant to almost all chemicals, and X-ray transparent. Machined with sharp carbide tooling — it generates fine chips that require thorough cleaning.
Acetal (Delrin / POM-C)
The first choice for low-friction sliding applications. Machines with exceptional precision and surface finish — it holds tight tolerances better than most metals due to its dimensional stability. Natural white colour or black available.
Not Sure Which Material to Choose?
Send us your drawing and application requirements. Our engineers review every quote submission for DFM (Design for Manufacturability) and will recommend the most cost-effective material and process.