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Steel

Mild Steel (1018 / 1045)

The workhorse of engineering — strong, cheap, weldable, and available everywhere.

Tensile Strength

400–620 MPa

Density

7.85 g/cm³

Max Temp

300°C continuous

Machinability

Mild steel (carbon steel grades 1018 and 1045) is the foundational engineering material. Its combination of good machinability, weldability, heat-treatability, and low cost makes it the default choice for structural brackets, machine bases, shafts, conveyor components, and general engineering hardware where corrosion resistance is not required. More steel is machined by volume in OrangeSea CNC's facility than any other ferrous material — we hold large stocks of bar, plate, and tube and maintain dedicated steel machining lines to prevent cross-contamination with stainless and aluminium.

Technical Data

Material Properties

Tensile Strength (1018)

400 MPa

Tensile Strength (1045)

570–620 MPa

Hardness (1018)

126 HB

Hardness (1045)

163–179 HB

Density

7.85 g/cm³

Machinability

Excellent (5/5)

Weldability

Excellent (all methods)

Heat Treatability

1045: Yes (through-harden)

Corrosion Resistance

Poor — surface treatment required

Max Service Temp

~300°C continuous

Capabilities

Why CNC Machine Mild Steel?

Lowest Material Cost

Mild steel is the most cost-effective engineering metal per kg and per unit of strength. Significant cost saving over stainless or aluminium for non-corrosion applications.

Excellent Machinability

1018 and 1045 both machine cleanly at high speeds with good surface finish and long tool life — translating to low cost per part.

Weldable

Both grades weld easily with MIG, TIG, and stick processes — essential for fabricated assemblies, frames, and structures.

Heat Treatable (1045)

1045 can be flame-hardened, induction-hardened, or through-hardened for wear surfaces — without the cost of tool steel.

Surface Treatment Versatile

Zinc plate, hot-dip galvanise, powder coat, paint, black oxide — all common treatments for mild steel are well-established at low cost.

Use Cases

What We Machine in Mild Steel

Industrial

Machine bases, brackets, shafts, conveyor components, jig frames, hydraulic cylinder bodies

Automotive

Chassis components, engine mounts, structural brackets, production fixtures

Construction

Structural brackets, anchor plates, machine foundations, fabricated frames

Energy

Pipeline supports, non-pressure structural components, equipment bases

Engineering Tips

Design for Machining — Mild Steel

Specify surface treatment — mild steel rusts within days of machining in humid environments. Zinc plate, phosphate + oil, or powder coat are common low-cost options

For through-hardening, specify 1045 (not 1018) — 1018's low carbon content prevents meaningful through-hardening

1018 is better for cold-heading, bending, and welding; 1045 is better for wear surfaces, keys, and splines

For parts requiring close tolerances after welding, leave machining allowance and finish-machine the weld assembly — heat distortion from welding makes pre-machined tolerances difficult to maintain

Surface Options