Materials in Precision Machining: From Steel to Thermoplastics

77 Teknik
Jul 26
3 min read

Updated: Aug 18

The success of any precision part whether in aerospace, medical, automotive, or industrial applications begins with selecting the right material. In CNC machining and advanced manufacturing, material choice is a critical factor influencing machinability, strength, durability, weight, and cost.

In this article, we break down the most commonly used materials in precision machining and explain why and where each is ideal.

Why Material Selection Matters

Choosing the right material affects:

Tolerances and surface finish quality
Tool wear and machining cycle times
Weight-to-strength ratio
Corrosion resistance and part lifespan
Overall project cost and performance

At 77 Teknik, we help customers select optimal materials based on their function, budget, and machining efficiency.

Common Materials in Precision Machining

1. Mild Steel (Carbon Steel)

Easy to machine, cost-effective, strong
Prone to rust; requires coating or painting
Used in machine components, brackets, general parts

2. Stainless Steel (e.g., 304, 316)

Corrosion-resistant, strong, hygienic
Harder to machine, causes more tool wear
Used in medical, food-grade, marine parts

3. Aluminum (e.g., 6061, 7075)

Lightweight, excellent machinability, good thermal conductivity
Lower strength vs steel, surface prone to scratching
Used in aerospace, electronics, automotive brackets

4. Titanium (e.g., Grade 2, Grade 5 - Ti-6Al-4V)

Exceptional strength-to-weight ratio, corrosion-resistant, biocompatible
Expensive, difficult to machine (low thermal conductivity)
Used in aerospace fasteners, implants, defense parts

5. Brass & Copper

Excellent electrical/thermal conductivity, easy to machine
Softer, not suitable for load-bearing parts
Used in electrical connectors, plumbing, decorative parts

6. POM (Delrin / Acetal)

High stiffness, excellent dimensional stability, low friction
Poor UV resistance
Used in gears, bearings, bushings, precision jigs

7. Nylon (PA6 / PA66)

Strong, abrasion-resistant, good under mechanical stress
Moisture absorption may affect tolerances
Used in mechanical housings, pulleys, spacers

8. PEEK (Polyetheretherketone)

High-temperature resistance, chemically inert, biocompatible
High cost, challenging to machine
Used in aerospace, medical implants, semiconductor equipment

9. PTFE (Teflon)

Very low friction, excellent chemical resistance
Soft, low wear resistance
Used in seals, gaskets, chemical liners

Material Comparison Table (Metals + Plastics)

Material	Machinability	Strength	Weight	Heat Resistance	Chemical Resistance	Cost
Mild Steel	★★★★★	★★★★☆	Heavy	High	Low	Low
Stainless Steel	★★★☆☆	★★★★★	Heavy	High	High	Medium
Aluminum	★★★★★	★★★☆☆	Light	Medium	Medium	Low-Mid
Titanium	★★☆☆☆	★★★★★	Light	Very High	Very High	High
Brass/Copper	★★★★★	★★☆☆☆	Medium	Medium	Medium	Mid-High
POM (Delrin)	★★★★★	★★★☆☆	Very Light	Medium	Medium	Low
Nylon	★★★★☆	★★★☆☆	Very Light	Medium	Medium	Low
PEEK	★★★☆☆	★★★★☆	Light	Very High	Very High	High
PTFE	★★★☆☆	★★☆☆☆	Very Light	Medium	Very High	Medium

Choosing the Right Material: Key Considerations

Functionality: Will the part endure high stress, friction, or corrosion?
Environment: Indoor, outdoor, medical, or marine use?
Cost vs Performance: Is weight or price more critical?
Volume: High volume production favors materials easier to machine.

77 Teknik’s Expertise in Material Machining

Our advanced CNC facility can machine a wide range of materials from steel to titanium with tight tolerances and excellent repeatability.

We offer:

Material consultation during design
In house testing and sample machining
Process optimization for tool life and cycle time
ISO compliant quality control and documentation

Let’s Choose the Right Material — Together

Not sure which material suits your design? Our engineers and technicians will guide you to the most effective and cost-efficient solution.

Contact 77 Teknik today for expert advice on your next precision machining project.