Refractory Metal S-65
ASTM B349 Grade S-65
S-65 is a high-purity, fine-grain powder-metallurgy beryllium supplied to ASTM B349 Grade S-65, with very low BeO content that gives higher ductility and toughness than S-200F.
Reference datasheet — S-65 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
S-65 tempers and conditions
S-65 is supplied in 3 conditions, soft to hard.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress-relieved / annealed (≈730–790 °C, vacuum) | Applied to machined optical and metrology parts to remove machining stresses and maximise long-term dimensional stability. | 205 | 320 | 5.5 | 108 HB | 41 % IACS |
Hot isostatic pressed | Choose for near-net shapes and the most isotropic properties in thick sections. | 240 | 365 | 5 | 120 HB | 40 % IACS |
Extruded bar / tube | Use where high longitudinal strength and stiffness in a slender section are needed (struts, tubes). | 330 | 460 | 8 | 132 HB | 39 % IACS |
Supply forms, finishes and certifications
Ways S-65 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PLATE | Rolled plate | Supply form |
Sheet-CR | Cross-rolled sheet | Supply form |
VHP-BlockDefault | VHP | Supply form |
What is S-65?
S-65 is a high-purity, fine-grain powder-metallurgy beryllium supplied to ASTM B349 Grade S-65, with very low BeO content that gives higher ductility and toughness than S-200F. Product forms include vacuum hot-pressed block, HIP near-net shapes, plate, cold-rolled sheet and extrusions, typically 230 MPa yield, 350 MPa tensile, 4.5% elongation, 78 HRB and 210 W/m·K. Cost and lead time are high, cold forming is not practical and fusion welding is difficult; machining dust requires enclosed wet or HEPA capture because of the beryllium sensitisation hazard. S-200F is the lower-cost structural alternative. S-65 has a density of 1.85 g/cm³ (0.0668 lb/in³), lighter than 96% of refractory metal grades. It melts at 1,287°C (2,349 °F). S-65 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 79% of refractory metal grades. Elongation at break is 4.5% and the elastic modulus is 303 GPa (43.9 Msi).
What is S-65 used for?
- precision optical mirrors
- space telescope structures
- high-reliability aerospace brackets
Advantages
- Easy to machine — 45/100, better than 99% of refractory metal grades
- Lightweight — 1.85 g/cm³ (0.0668 lb/in³), better than 96% of refractory metal grades
- Conducts heat well — 210 W/m·K (121.3 BTU/hr·ft·°F), better than 94% of refractory metal grades
- High electrical conductivity — 40 % IACS, better than 93% of refractory metal grades
Limitations
- High embodied carbon — 250 kg CO₂/kg, worse than 89% of refractory metal grades
- Needs corrosion protection — 45/100, worse than 86% of refractory metal grades
- Low fracture toughness — 13 MPa·√m (11.8 ksi·√in), worse than 82% of refractory metal grades
- Limited ductility — 4.5%, worse than 81% of refractory metal grades
- Limited formability — 15/100, worse than 80% of refractory metal grades
S-65 properties
Typical room-temperature values; bars are the position among refractory metal grades.
Physical3
S-65 has a density of 1.85 g/cm³ (0.0668 lb/in³), lighter than 96% of refractory metal grades. It melts at 1,287°C (2,349 °F).
Mechanical13
S-65 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 79% of refractory metal grades. Elongation at break is 4.5% and the elastic modulus is 303 GPa (43.9 Msi).
Thermal6
S-65 is rated for continuous service to 500°C (932 °F). It conducts heat at 210 W/m·K (121.3 BTU/hr·ft·°F), better than 94% of refractory metal grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
S-65 conducts electricity at 40 % IACS, better than 93% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 86% of refractory metal grades.
Sustainability4
Producing a kilogram of S-65 takes about 4,000 MJ of energy and emits 250 kg of CO₂ — more than 89% of refractory metal grades. Typical recycled content is 15%.
Manufacturability8
S-65's machinability is fair (45/100, better than 99% of refractory metal grades); weldability poor (20/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. S-65 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S-65
Is S-65 easy to machine?
Machines like a hard, abrasive cast iron with carbide/PCD tooling and low feeds; all dust and coolant must be captured (Be sensitisation/CBD hazard), and a light chemical etch removes the damaged twinned surface layer.
Can S-65 be welded?
Fusion welding is difficult (hot cracking, coarse grain); electron-beam welding with Al-Si filler, Ag-based brazing or mechanical/adhesive joining are preferred.
Can S-65 be formed, bent or molded?
Cold formability is essentially nil due to the hcp structure; forming, bending and deep drawing are done warm (400–800 °C), often with steel cladding.
S-65 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 |
|---|---|---|
| BeOberyllium oxide content, low-oxide grade | ≤ 1 | 0.7 |
| Fe | ≤ 0.08 | 0.05 |
| C | ≤ 0.1 | 0.06 |
| Al | ≤ 0.06 | 0.03 |
| Mg | ≤ 0.06 | 0.02 |
| Si | ≤ 0.06 | 0.02 |
| other metallic impurities (each)per element | ≤ 0.04 | |
| Beassay, minimum | ≥ 99 (balance) |
What surface finishes work on S-65?
Not anodizable in the aluminium sense — use chromate conversion coating, electroless nickel or Ni plating; optical surfaces are diamond-turned/polished after etching and often nickel-plated.
Equivalent designations
Standards and trade names that resolve to Refractory Metal S-65 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B349 Grade S-65
How much does S-65 cost?
S-65 is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S-65 — frequently asked
What is S-65 used for?
S-65 is typically used for precision optical mirrors, space telescope structures and high-reliability aerospace brackets. In short: most ductile beryllium grade; very low BeO content; aerospace-standard Be grade.
What is the yield strength of S-65?
S-65 has a typical yield strength of 230 MPa (33.4 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 79% of refractory metal grades. Strength varies by condition: see the 3 listed tempers.
Is S-65 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 99% of refractory metal grades). Machines like a hard, abrasive cast iron with carbide/PCD tooling and low feeds; all dust and coolant must be captured (Be sensitisation/CBD hazard), and a light chemical etch removes the damaged twinned surface layer.
Can S-65 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is difficult (hot cracking, coarse grain); electron-beam welding with Al-Si filler, Ag-based brazing or mechanical/adhesive joining are preferred.
What surface finishes work on S-65?
Not anodizable in the aluminium sense — use chromate conversion coating, electroless nickel or Ni plating; optical surfaces are diamond-turned/polished after etching and often nickel-plated.
Can S-65 be formed, bent or molded?
Cold formability is essentially nil due to the hcp structure; forming, bending and deep drawing are done warm (400–800 °C), often with steel cladding.
What is the maximum service temperature of S-65?
S-65 is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does S-65 cost?
S-65 is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B349/B349M — Beryllium grades (S-65 chemistry and mechanical requirements) — ASTM International (2020)
- Structural beryllium grades S-65 / S-200F product data — Materion Beryllium & Composites (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Beryllium) — ASM International (1990)
- Beryllium: Chemistry, Metallurgy and Applications — technical literature (2009)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.