Solder & Low-Melting Alloy B23 Grade 7 AS-CAST
Heat-treated state · default condition
ASTM B23 Grade 7 · UNS L53585
Standard condition for hand-poured/gravity-cast babbitt linings in split shells and bushings.
Values for the AS-CAST condition
Other B23 Grade 7 tempers and conditions
B23 Grade 7 is listed in 2 conditions; see the grade overview at B23 Grade 7.
- AS-CAST
- CENT-CAST
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AS-CASTDefaultThis page statically (gravity) cast bearing lining | Standard condition for hand-poured/gravity-cast babbitt linings in split shells and bushings. | 25 | 50 | 4 | 23 HB | 5 % IACS |
spun lining on steel/bronze shell | Choose for thin, dense, porosity-free linings with a finer structure and better bond/fatigue life. | 28 | 55 | 4 | 24 HB | 5 % IACS |
What is B23 Grade 7 AS-CAST?
B23 Grade 7 AS-CAST is B23 Grade 7 heat treated to AS-CAST — standard condition for hand-poured/gravity-cast babbitt linings in split shells and bushings. B23 Grade 7 AS-CAST has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 4% and the elastic modulus is 25 GPa (3.63 Msi). B23 Grade 7 AS-CAST has a density of 9.73 g/cm³ (0.352 lb/in³), heavier than 73% of solder & low-melting alloy grades. It melts at 240°C (464 °F).
Advantages
- Easy to machine — 88/100, better than 92% of solder & low-melting alloy grades
- Low embodied carbon — 2.2 kg CO₂/kg, better than 88% of solder & low-melting alloy grades
- Polishes to a fine finish — 60/100, better than 82% of solder & low-melting alloy grades
Limitations
- Limited formability — 15/100, worse than 99% of solder & low-melting alloy grades
- Limited ductility — 4%, worse than 91% of solder & low-melting alloy grades
- Low electrical conductivity — 5 % IACS, worse than 90% of solder & low-melting alloy grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 86% of solder & low-melting alloy grades
B23 Grade 7 AS-CAST properties
Typical room-temperature values for B23 Grade 7 AS-CAST; 18 are specific to this condition. Other listed values are B23 Grade 7 reference data and may not represent this condition. Bars are the position among solder & low-melting alloy grades.
Physical3
B23 Grade 7 AS-CAST has a density of 9.73 g/cm³ (0.352 lb/in³), heavier than 73% of solder & low-melting alloy grades. It melts at 240°C (464 °F).
Mechanical11
B23 Grade 7 AS-CAST has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 4% and the elastic modulus is 25 GPa (3.63 Msi).
Thermal6
B23 Grade 7 AS-CAST is rated for continuous service to 120°C (248 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 86% of solder & low-melting alloy grades. Thermal expansion is 24 µm/m·K (13.3 µin/in·°F).
Electrical3
B23 Grade 7 AS-CAST conducts electricity at 5 % IACS, worse than 90% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 82% of solder & low-melting alloy grades.
Sustainability3
Producing a kilogram of B23 Grade 7 AS-CAST takes about 26 MJ of energy and emits 2.2 kg of CO₂ — less than 93% of solder & low-melting alloy grades. Typical recycled content is 60%.
Manufacturability7
B23 Grade 7 AS-CAST's machinability is excellent (88/100, better than 92% of solder & low-melting alloy grades); weldability poor (20/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with B23 Grade 7 AS-CAST
Is B23 Grade 7 easy to machine?
Very soft and gummy — bore/scrape with sharp, high-rake HSS or carbide, high speed, light feed and generous flood coolant to avoid smearing over oil grooves.
Can B23 Grade 7 be welded?
Not fusion welded; repair by re-tinning and re-pouring, or by low-heat babbitt build-up with a soft-flame/soldering technique to avoid burning off tin and antimony.
Can B23 Grade 7 be formed, bent or molded?
Cast only: tin the steel shell (zinc-chloride flux + 50/50 solder), preheat shell ~260–290 °C and pour at roughly 350–380 °C, then chill from the back to drive directional solidification and avoid Sb-Sn segregation.
What surface finishes work on B23 Grade 7?
Finish by boring/scraping to bearing clearance; do not plate or anodize — protect stored linings with light oil, and handle as a lead-bearing material (fume/dust controls, RoHS-exempt applications only).
B23 Grade 7 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Sn | 4.5 – 5.5 | 5 |
| Sb | 9.3 – 10.7 | 10 |
| Ashardener, refines structure | 0.3 – 0.6 | 0.45 |
| Cusome producer/market specs quote 0.3–0.7 % Cu | ≤ 0.5 | 0.25 |
| Feimpurity limit | ≤ 0.1 | — |
| Biimpurity limit | ≤ 0.1 | — |
| Znimpurity limit | ≤ 0.01 | — |
| Alimpurity limit | ≤ 0.01 | — |
| Pbremainder, ~80–85 % | balance | — |
B23 Grade 7 AS-CAST — frequently asked
What is B23 Grade 7 AS-CAST used for?
B23 Grade 7 AS-CAST is typically used for plain bearing linings, diesel engine main/rod bearings, machine tool slideway inserts and general industrial bushings. In short: low-cost lead-base babbitt; good conformability and embeddability; lower load than tin babbitt.
What is the yield strength of B23 Grade 7 AS-CAST?
B23 Grade 7 AS-CAST has a typical yield strength of 25 MPa (3.63 ksi) and a tensile strength of 50 MPa (7.25 ksi) — weaker than 61% of solder & low-melting alloy grades. Strength varies by condition: see the 2 listed tempers.
Is B23 Grade 7 AS-CAST easy to machine?
Yes — machinability is rated excellent (88/100, better than 92% of solder & low-melting alloy grades). Very soft and gummy — bore/scrape with sharp, high-rake HSS or carbide, high speed, light feed and generous flood coolant to avoid smearing over oil grooves.
Can B23 Grade 7 AS-CAST be welded?
Not readily — weldability is rated poor (20/100). Not fusion welded; repair by re-tinning and re-pouring, or by low-heat babbitt build-up with a soft-flame/soldering technique to avoid burning off tin and antimony.
What surface finishes work on B23 Grade 7 AS-CAST?
Finish by boring/scraping to bearing clearance; do not plate or anodize — protect stored linings with light oil, and handle as a lead-bearing material (fume/dust controls, RoHS-exempt applications only).
Can B23 Grade 7 AS-CAST be formed, bent or molded?
Cast only: tin the steel shell (zinc-chloride flux + 50/50 solder), preheat shell ~260–290 °C and pour at roughly 350–380 °C, then chill from the back to drive directional solidification and avoid Sb-Sn segregation.
What is the maximum service temperature of B23 Grade 7 AS-CAST?
B23 Grade 7 AS-CAST is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM B23 — Standard Specification for White Metal Bearing Alloys (Known Commercially as Babbitt Metal) — ASTM International (2021)
- ASM Handbook, Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (bearing alloys) — ASM International (1990)
- ASM Handbook, Vol. 18 — Friction, Lubrication, and Wear Technology — ASM International (2017)
- GB/T 1174 (ZPbSb10Sn6 ) (1992)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.