Antimonial Lead, designated under UNS grades L52500–L53799, refers to lead–antimony alloys engineered to deliver significantly higher strength, hardness, wear resistance, and casting quality compared to pure lead.
These alloys retain lead’s excellent density, corrosion resistance, and radiation shielding while providing the rigidity and creep resistance required for demanding structural and battery applications.
Microstructure & Metallurgical Behavior
Crystal Structure: FCC lead matrix
Microstructure:
Lead-rich α phase with dispersed antimony-rich intermetallic phases (PbSb, SbSn)
| Strengthening Mechanism | Contribution |
|---|---|
| Solid-solution strengthening | Limited |
| Intermetallic dispersion | Primary strengthening mechanism |
| Age hardening | Yes (natural aging) |
Metallurgical Insight:
Antimony significantly improves hardness, rigidity, and wear resistance, but
progressively reduces ductility as antimony content increases.
Corrosion & Chemical Resistance
✔ Excellent resistance to sulfuric acid
✔ Good resistance in industrial atmospheres and soil environments
✔ Retains lead’s natural oxidation resistance
❌ Slightly reduced acid resistance at high Sb levels compared to pure lead
Casting, Processing & Refining
| Process | Behavior |
|---|---|
| Casting | Excellent fluidity, low shrinkage |
| Forming | Limited cold workability at high Sb % |
| Machining | Improved vs pure lead, still smear-prone |
| Joining | Soldering and lead burning possible |
| Refining | Tightly controlled Sb alloying |
Available Forms
Battery grids and plates
Ingots
Sheets and strips
Cast blocks and shapes
Shot and ballast
Key Characteristics
✔ Much higher strength than pure lead
✔ Excellent creep resistance
✔ Good wear resistance
✔ Superior casting accuracy
✔ Dimensional stability under load
✔ Retains lead’s density and shielding capability
Applications
Battery Industry (Primary Use)
Lead-acid battery grids
Deep-cycle batteries
Traction and industrial batteries
Construction & Infrastructure
Expansion joints
Roofing ballast
Vibration damping blocks
Radiation & Ballast
Counterweights
Rigid radiation shielding components
Industrial
Bearing linings
Wear-resistant lead components
Advantages of Antimonial Lead
✔ Much stronger than pure lead
✔ Excellent casting behavior
✔ Good resistance to deformation
✔ Long service life under load
✔ Proven battery grid material
Why Choose Antimonial Lead (L52500 – L53799)?
Choose antimonial lead when high rigidity, creep resistance, dimensional stability, and casting precision are required—and when pure lead is too soft for the application.
Engineering Summary:
Antimonial Lead alloys are structural lead materials, delivering the strength,
hardness, and durability needed for demanding battery, casting, and industrial
applications while preserving lead’s corrosion resistance and density.