Refractory Metal I-220H HIP-SR
Heat-treated state
HIP-SR = hIP + thermal stress relief / dimensional stabilization
Pick when long-term dimensional stability and high microyield strength matter (gyro and inertial platform parts) — relieves machining residual stress at slight strength loss.
Values for the HIP-SR condition
Other I-220H tempers and conditions
I-220H is listed in 2 conditions; see the grade overview at I-220H.
- HIP-SR
- HIP
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HIP-SRThis page HIP + thermal stress relief / dimensional stabilization | Pick when long-term dimensional stability and high microyield strength matter (gyro and inertial platform parts) — relieves machining residual stress at slight strength loss. | 330 | 430 | 2.5 | 170 HB | 40 % IACS |
HIPDefault Hot isostatic pressed | Standard supply condition: fully dense, isotropic HIP block, rod or plate for machined instrument and structural parts. | 345 | 462 | 2 | 180 HB | 40 % IACS |
What is I-220H HIP-SR?
I-220H HIP-SR is I-220H heat treated to HIP-SR — pick when long-term dimensional stability and high microyield strength matter (gyro and inertial platform parts) — relieves machining residual stress at slight strength loss. I-220H HIP-SR has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 50% of refractory metal grades. Elongation at break is 2.5% and the elastic modulus is 303 GPa (43.9 Msi). I-220H HIP-SR 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). HIP is the default condition FabDigit quotes; HIP-SR is available on request or by drawing note.
Advantages
- Lightweight — 1.85 g/cm³ (0.0668 lb/in³), better than 96% of refractory metal grades
- High electrical conductivity — 40 % IACS, better than 93% of refractory metal grades
- Conducts heat well — 195 W/m·K (112.7 BTU/hr·ft·°F), better than 91% of refractory metal grades
Limitations
- Limited ductility — 2.5%, worse than 93% of refractory metal grades
- Low fracture toughness — 11 MPa·√m (10 ksi·√in), worse than 92% of refractory metal grades
- Limited formability — 7/100, worse than 91% of refractory metal grades
- Hard to polish — 55/100, worse than 90% of refractory metal grades
- Needs corrosion protection — 45/100, worse than 86% of refractory metal grades
I-220H HIP-SR properties
Typical room-temperature values for I-220H HIP-SR; 22 are specific to this condition. Other listed values are I-220H reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
I-220H HIP-SR 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).
Mechanical16
I-220H HIP-SR has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 50% of refractory metal grades. Elongation at break is 2.5% and the elastic modulus is 303 GPa (43.9 Msi).
Thermal6
I-220H HIP-SR is rated for continuous service to 500°C (932 °F). It conducts heat at 195 W/m·K (112.7 BTU/hr·ft·°F), better than 91% of refractory metal grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
I-220H HIP-SR 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 I-220H HIP-SR takes about 3,500 MJ of energy and emits 210 kg of CO₂ — more than 86% of refractory metal grades. Typical recycled content is 15%.
Manufacturability7
I-220H HIP-SR's machinability is poor (27/100, worse than 60% of refractory metal grades); weldability poor (22/100); formability not recommended (7/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with I-220H HIP-SR
Is I-220H easy to machine?
Machine with sharp carbide/diamond tooling, light finish passes and full HEPA/wet dust containment; follow with acid etch to remove the twinned, microcracked surface layer.
Can I-220H be welded?
Essentially non-weldable by fusion arc processes (hot cracking); use electron-beam welding with Al-Be filler or mechanical/brazed joints instead.
Can I-220H be formed, bent or molded?
No practical cold forming — parts are HIP near-net billets that are machined; hot working only above ~700 °C in specialized facilities.
What surface finishes work on I-220H?
Chromate conversion coat, electroless nickel or paint for corrosion protection; can be lapped/polished but I-70H is preferred for optical surfaces.
I-220H 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 |
|---|---|---|
| BeOdispersed oxide from powder; sets the '220' designation | 1.8 – 2.6 | 2.2 |
| Al | ≤ 0.1 | — |
| C | ≤ 0.15 | — |
| Fe | ≤ 0.15 | — |
| Mg | ≤ 0.08 | — |
| Si | ≤ 0.08 | — |
| other metallic eachper producer specification | ≤ 0.04 | — |
| Beassay, balance; BeO reported separately | ≥ 98 (balance) | — |
I-220H HIP-SR — frequently asked
What is I-220H HIP-SR used for?
I-220H HIP-SR is typically used for aerospace structural brackets, satellite components and precision mechanisms. In short: strongest instrument-grade beryllium; structural Be, low elongation; HIP near-net billet stock.
What is the yield strength of I-220H HIP-SR?
I-220H HIP-SR has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 430 MPa (62.4 ksi) — stronger than 50% of refractory metal grades. Strength varies by condition: see the 2 listed tempers.
Is I-220H HIP-SR easy to machine?
Not especially — machinability is rated poor (27/100, worse than 60% of refractory metal grades). Machine with sharp carbide/diamond tooling, light finish passes and full HEPA/wet dust containment; follow with acid etch to remove the twinned, microcracked surface layer.
Can I-220H HIP-SR be welded?
Not readily — weldability is rated poor (22/100). Essentially non-weldable by fusion arc processes (hot cracking); use electron-beam welding with Al-Be filler or mechanical/brazed joints instead.
What surface finishes work on I-220H HIP-SR?
Chromate conversion coat, electroless nickel or paint for corrosion protection; can be lapped/polished but I-70H is preferred for optical surfaces.
Can I-220H HIP-SR be formed, bent or molded?
No practical cold forming — parts are HIP near-net billets that are machined; hot working only above ~700 °C in specialized facilities.
What is the maximum service temperature of I-220H HIP-SR?
I-220H HIP-SR 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.
What is the difference between I-220H-HIP and I-220H HIP-SR?
HIP is the default condition — standard supply condition: fully dense, isotropic HIP block, rod or plate for machined instrument and structural parts. HIP-SR: pick when long-term dimensional stability and high microyield strength matter (gyro and inertial platform parts) — relieves machining residual stress at slight strength loss. Yield strength is 345 MPa in HIP versus 330 MPa in HIP-SR.
Sources
- Beryllium Structural and Instrument Grades (S-65C, S-200F, I-70H, I-220H) product data — Materion Brush Beryllium & Composites (2022)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Beryllium) — ASM International (1990)
- Beryllium Chemistry and Processing — ASM International (2009)
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.