C93200 SAE 660 Bearing Bronze: High-Lead Tin Bronze vs C36000 Free-Cutting Brass: The Machinability Standard
Side-by-side engineering comparison of C93200 SAE 660 Bearing Bronze: High-Lead Tin Bronze (ASTM B505/B271) and C36000 Free-Cutting Brass: The Machinability Standard (ASTM B16/B116). Compare mechanical properties, chemical composition, density, yield strength, international equivalents, and typical applications to select the right material for your project.
Quick Verdict
Choose C93200 bearing bronze when the application involves sliding contact under load — bushings, bearings, wear plates, and gears — where embedded lubrication and wear resistance are essential. Choose C36000 free-cutting brass for general machined components, fittings, and hardware where cost and machinability matter more than tribological performance....
Bearing performance and wear resistance under sliding loads
Machinability, cost, and formability for general mechanical parts
Quick Comparison
| Property | C93200 SAE 660 Bearing Br | C36000 Free-Cutting Brass |
|---|---|---|
| Standard | ASTM B505/B271 | ASTM B16/B116 |
| Category | Brass & Bronze | Brass & Bronze |
| Density | 8.93 g/cm³ | 8.50 g/cm³ |
| Yield Strength | 125 MPa (18 ksi) | 124 MPa (18 ksi) annealed; 310 MPa (45 ksi) hard |
| Tensile Strength | 240 MPa (35 ksi) | 338 MPa (49 ksi) annealed; 469 MPa (68 ksi) hard |
| Key Applications | C93200 (SAE 660) is a continuously cast high-lead tin bronze (81-85% Cu, 6.3-7.5% Sn, 6-8% Pb, 2-4% Zn) that is the glob... | C36000 free-cutting brass (61.5% Cu, 35.5% Zn, 3% Pb) is the standard against which all other metals' machinability is m... |
International Equivalents
| C93200 SAE 660 Beari Equivalents | C36000 Free-Cutting Equivalents |
|---|---|
| EN CuSn7Zn4Pb7 | EN CuZn36Pb3 |
| CC493K | CW603N |
| JIS CAC406 | JIS C3601 |
| ZCuSn5Pb5Zn5 | HPb59-1 |
| SAE 660 | ISO CuZn36Pb3 |
How to Choose
| Choose C93200 SAE 660 Bearing Br when... | C93200 bearing bronze (SAE 660) provides embedded solid lubrication and wear resistance for bushings and bearings under sliding loads. |
| Choose C36000 Free-Cutting Brass when... | C36000 free-cutting brass offers 100% machinability at lower cost for screw-machine products, fittings, and hardware. |
Decision Checklist: Which Is Right for You?
| Criterion | C93200 SAE 660 Beari | C36000 Free-Cutting |
|---|---|---|
| Bearing Performance And Wear Resistance Under Sliding Loads | ✓ | |
| Machinability, Cost, And Formability For General Mechanical Parts | ✓ | |
| Tribological performance — C93200 is engineered for sliding contact wi... | ✓ | |
| Machinability — C36000 is the industry 100% machinability benchmark; C... | ✓ | |
| Strength — C93200 provides 450 MPa tensile (cast) vs 460 MPa for C3600... | ✓ |
Selection Guide
Choose C93200 bearing bronze when the application involves sliding contact under load — bushings, bearings, wear plates, and gears — where embedded lubrication and wear resistance are essential. Choose C36000 free-cutting brass for general machined components, fittings, and hardware where cost and machinability matter more than tribological performance. Bronze for bearings; brass for machined parts.
Key Decision Factors
- Tribological performance — C93200 is engineered for sliding contact with embedded solid lubrication (lead) and wear resistance (tin); C36000 has poor bearing properties and will gall under sliding load
- Machinability — C36000 is the industry 100% machinability benchmark; C93200 machines at approximately 80% rating (still good, but slower than C36000)
- Strength — C93200 provides 450 MPa tensile (cast) vs 460 MPa for C36000 (wrought) — comparable, but C36000 has higher ductility
- Cost — C36000 typically costs 15-25% less than C93200 per kg due to simpler production (wrought vs cast) and lower tin content
When to Use Each
Use C93200 SAE 660 Beari for:
C93200 (SAE 660) contains 7% tin and 7% lead, providing a soft matrix that embeds debris and a low-friction surface — the standard for slow-speed, heavy-load bushings in industrial machinery.
C93200's lead particles act as solid lubricants during sliding contact, reducing friction and galling between mating steel surfaces in machine tools and heavy equipment.
Bronze worm wheels running against steel worms provide wear resistance and quiet operation — the lead-tin microstructure resists scoring under high sliding velocities at the gear mesh.
Use C36000 Free-Cutting for:
C36000's 100% machinability rating enables high-speed, high-volume production of bolts, nuts, inserts, and fittings at low cost — the workhorse brass for automatic screw machines.
C36000 provides 460 MPa tensile strength with good corrosion resistance in freshwater, making it standard for faucet bodies, valve stems, and compression fittings.
C36000's warm gold color, ability to be polished or plated, and moderate cost make it the standard for decorative door hardware, lighting fixtures, and consumer products.
Frequently Asked Questions
What is the main difference between C93200 SAE 660 Bearing Bronze: and C36000 Free-Cutting Brass: The?
C93200 SAE 660 Bearing Bronze: High-Lead Tin Bronze (ASTM B505/B271) provides 125 MPa (18 ksi) yield strength at 8.93 g/cm³ density, while C36000 Free-Cutting Brass: The Machinability Standard (ASTM B16/B116) delivers 124 MPa (18 ksi) annealed; 310 MPa (45 ksi) hard at 8.50 g/cm³. The choice depends on whether your application prioritizes bearing performance and wear resistance under sliding loads or machinability, cost, and formability for general mechanical parts.
Can C93200 SAE 660 Bearing Bronze: be substituted for C36000 Free-Cutting Brass: The?
In many applications, these materials can be cross-referenced, but direct substitution should always be verified against specific project specifications, especially for bearing performance and wear resistance under sliding loads, machinability, cost, and formability for general mechanical parts, and operating environment. Consult your engineer of record.
Can C36000 brass be used as a bearing?
Not recommended. C36000 has no solid lubricant phase (its lead is dispersed for machinability, not lubrication) and will gall, score, and seize against steel shafts under sliding load. For bearing applications, always specify a bearing bronze like C93200 (SAE 660), C95400 (aluminum bronze), or oil-impregnated porous bronze. Brass is suitable for static or slowly rotating low-load applications only.
Why does C93200 contain lead?
C93200 (SAE 660) contains 7% lead, which serves two purposes: (1) it acts as a solid lubricant during sliding contact, reducing friction and wear against steel shafts; (2) it improves machinability by acting as a chip breaker. The lead is distributed as discrete particles throughout the bronze matrix. For lead-free bearing applications (RoHS, drinking water), use C95400 aluminum bronze or lead-free bearing bronze grades with bismuth or graphite lubricants.
What does 'SAE 660' mean?
SAE 660 is the industry designation for C93200 bearing bronze — a copper-tin-lead-zinc alloy (7% Sn, 7% Pb, 3% Zn, balance Cu). 'SAE 660' refers to the Society of Automotive Engineers standard J459C composition, widely used in the bearing industry. C93200 and SAE 660 are interchangeable designations — C93200 is the UNS (Unified Numbering System) designation, while SAE 660 is the legacy SAE designation. The alloy is also sometimes called 'leaded tin bronze' or 'gear bronze'.
Can C93200 bronze be welded?
C93200 is difficult to weld due to its lead content. Lead vaporizes at welding temperatures (1750°C) and causes porosity and toxic fumes. For repair of C93200 castings, use brazing with a silver-bearing filler (BAg series) or bronze braze filler (RBCuZn-A). For new fabrication requiring welding, consider C95400 aluminum bronze (weldable with matching filler) or C63000 nickel-aluminum bronze. C36000 brass can be brazed readily but is also not fusion-welded in production.
Which material is better for a gear?
For a worm wheel or slow-speed gear meshing against a steel gear, C93200 bronze is the standard choice — its wear resistance and embedded lubrication prevent scoring and extend gear life. For small, high-speed gears in instrument mechanisms, C36000 brass is sometimes used where loads are light and quiet operation matters. For power-transmission gears under high load, use hardened steel (AISI 4140, 8620 carburized, or 9310). Bronze and brass gears are limited to low-speed, low-load applications.