Mild steel
High machinability and weldability, high stiffness.
- Common grades
- 1018 / S20C · 1045 / S45C · 12L14 · S355 / A36 plate
- Machinability
- Mild steel is the economical workhorse: low material cost, predictable cutting, good weldability.
- Tolerances
- ±0.025 mm standard on linear dimensions; ±0.010 mm on critical features
- Processes
- CNC milling, CNC turning and 5-axis machining
- Finishes
- Zinc plating · Black oxide · Phosphate coating · Case hardening
- Used in
- Automotive, Oil & Gas
- Certification
- Mill test certificate (chemistry and mechanical properties) with every lot; EN 10204 3.1 certificates on request
Machining Mild steel
Mild steel is the economical workhorse: low material cost, predictable cutting, good weldability. It machines with stable chip formation and takes handling well, making it the right choice for fixtures, base plates, brackets and machine components that do not need alloy-steel strength.
Because low-carbon steel cannot be through-hardened, wear surfaces are case-hardened instead: carburizing gives a hard skin over a tough core. We machine, manage heat treatment, and finish-machine critical features afterwards so tolerances hold.
Bare mild steel rusts, so parts almost always carry a finish: black oxide, zinc plating or paint. We machine to allow for plating thickness when drawings call for post-plate dimensions, and hold ±0.025 mm on critical features.
Common Grades We Machine
- 1018 / S20C - The standard low-carbon grade: good machinability and weldability for general parts and case-hardened components.
- 1045 / S45C - Medium-carbon step-up that can be flame- or induction-hardened for shafts and gears at low cost.
- 12L14 - Free-machining leaded grade for high-volume turned parts where productivity matters most.
- S355 / A36 plate - Structural plate for bases, weldments and machine frames.
Applications by Industry
- Automotive - brackets, spacers and case-hardened wear components at production volumes.
- Oil & Gas - structural components and fixtures where painted or plated carbon steel is specified.
Surface Finishing Options
- Zinc plating - economical corrosion protection for handling and indoor service.
- Black oxide - a uniform dark finish with mild corrosion resistance and no dimensional change.
- Phosphate coating - oil retention and break-in on sliding surfaces.
- Case hardening - carburized wear surfaces over a tough core, finish-machined after heat treatment.
See our surface finishing services for the full range.
Frequently Asked Questions
When is mild steel the right choice over alloy steel?
When the part needs stiffness, weldability and economy rather than high strength or fatigue resistance: fixtures, brackets, base plates and guards. If the part sees high stress or impact, step up to an alloy grade.
How do you stop mild steel parts from rusting?
Almost every mild steel part ships with a finish (zinc plating, black oxide or phosphate), and we machine to allow for plating thickness on toleranced features.
Can mild steel parts be hardened?
Low-carbon grades are case-hardened rather than through-hardened: carburizing produces a hard, wear-resistant skin over a tough core. We finish-machine critical dimensions after heat treatment.
Precision Mild steel Manufacturing in Singapore
Need complex Mild steel parts manufactured to tight tolerances? Explore our 5-axis simultaneous CNC machining, CNC milling, CNC turning and certified ISO Class 6–8 cleanroom assembly capabilities.
Speak with Our Sales & Engineering Team
Explore how Shine's Singapore precision CNC machining and cleanroom assembly integrate into your global supply chain. We welcome technical consultations, mutual NDAs, and facility audits.
- Mutual NDA executed within 24 hours
- ISO 9001:2015 certified & Cyber Essentials mark
- 24–48h engineering DFM feedback & formal RFQ pricing