How Strong is Silicon Metal?

This is a tricky question to answer simply because "strength" can mean different things.

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  ​​Pure Silicon Crystal:​​ In its pure, single-crystal form (like a wafer for computer chips), silicon is ​​very hard​​ (about a 6.5 on the Mohs hardness scale, similar to quartz or titanium). However, it is also ​​extremely brittle​​ (like glass). It has high ​​compressive strength​​ but very low ​​tensile strength​​ (it shatters easily if bent or struck).

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  ​​Commercial Silicon Metal:​​ The product sold as "silicon metal" is a polycrystalline material. It is also very hard and exceptionally brittle. You can break it with a hammer. Its "strength" is not why it's used; it's valued for its chemical and electrical properties.

Its real "strength" is revealed when it's used as an alloying element. Adding small amounts of silicon to ​​aluminum​​ or ​​steel​​ makes those alloys significantly stronger and harder.