C172 Beryllium Copper vs C110 Copper
C172 beryllium copper and C110 ETP copper sit at opposite ends of the copper-alloy spectrum. C110 is near-pure copper chosen for maximum electrical and thermal conductivity. C172 sacrifices much of that conductivity for extreme, heat-treatable strength — the strongest copper alloy made — used for springs, connectors and mold inserts that need both useful conductivity and high hardness.
The verdict
Choose C110 copper when conductivity is the whole point — busbars, terminals, heat sinks — and strength is secondary. Choose C172 beryllium copper when the part must carry mechanical load, act as a spring, or resist wear while retaining moderate conductivity — age-hardenable to ~1300 MPa nominal versus C110's soft ~220 MPa.
Side-by-side data
| Property | C172 Beryllium Copper | C110 Copper |
|---|---|---|
| Category | Copper Alloy | Copper Alloy |
| Density (g/cm³) | 8.25 | 8.94 |
| Tensile strength (MPa) | 1300 | 220 |
| Yield strength (MPa) | 1100 | 70 |
| Elongation (%) | 4 | 45 |
| Hardness | 40 HRC | 40 HB |
| Max service temp (°C) | 200 | 200 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 105 | 391 |
| Typically used for | Springs & non-sparking tools | Electrical & thermal conductivity parts |
Which should you choose?
Choose C172 Beryllium Copper when…
- You need strength no other copper alloy offers — ~1300 MPa tensile, ~1100 MPa yield nominal after aging
- The part is a spring, connector or contact that must hold high force without relaxing
- Mold cores and inserts need high hardness plus enough conductivity to pull heat
- Non-sparking tools are required in flammable environments
- Parts can be machined or formed soft, then age-hardened to final properties
- Wear and fatigue resistance matter more than maximum conductivity
Choose C110 Copper when…
- Maximum electrical and thermal conductivity (391 W/m·K nominal) is the primary requirement
- The part is a busbar, terminal, lug, heat sink or grounding component
- High ductility (~45% elongation) for bending and forming is needed
- The part is welded or brazed — no beryllium handling concerns
- Lower cost (3.0 vs 4.5) and no heat-treat step help economics
- Mechanical strength is low-priority and the part is mainly a conductor
Key differences that matter
- Strength gap is enormous: C172 ~1300 MPa tensile and ~40 HRC nominal versus C110's ~220 MPa and 40 HB soft.
- Conductivity gap is the inverse: C110 ~391 W/m·K thermal nominal versus C172 ~105 W/m·K — C172 keeps useful but far lower conductivity.
- C172 is age-hardenable — soft machining then heat treat; C110 is used soft or cold-worked only.
- C110 is highly ductile (~45% elongation) for forming; C172 in hardened state is low-elongation (~4%).
- Beryllium copper needs controlled dust/fume handling in machining; C110 has no such requirement.
- C110 is cheaper (3.0 vs 4.5) and weldable; C172 buys strength and spring performance at a premium.
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Open the Material SelectorGet a Quote →Frequently asked questions
Does beryllium copper conduct electricity like pure copper?
No — C172 keeps only moderate conductivity, around 105 W/m·K thermal (nominal) and roughly 22–28% IACS electrically, far below C110's ~100% IACS and 391 W/m·K. You choose C172 when you need its strength and can accept reduced conductivity; for a pure conductor C110 is dramatically better.
Why use C172 for injection-mold inserts instead of steel or C110?
Mold cores and slides often need to pull heat fast while resisting wear and deformation. C172 offers a useful blend: far higher thermal conductivity than tool steel to cool the part, plus high hardness (~40 HRC nominal) to survive cycling. C110 conducts better but is too soft to hold up as a mold surface.
Can both be welded?
C110 welds and brazes cleanly and is commonly joined that way for electrical assemblies. C172 can be joined but the beryllium content complicates welding and adds fume-handling concerns, so mechanical fastening or soldering is more typical. If welding is central to the design, C110 is the straightforward choice.
Which costs more and why?
C172 costs more (4.5 vs 3.0). It carries an alloying premium for beryllium, requires an age-hardening heat-treat step, and demands controlled machining for dust safety. C110 is near-pure copper with no heat treat and no special handling, so it's cheaper — appropriate when you only need conductivity, not strength.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.