SC-Cut vs AT-Cut Quartz Crystals — What's the Difference?

The "cut" of a quartz crystal — the precise angle at which a thin wafer is sliced from the raw quartz — has a major effect on how it behaves electrically and thermally. AT-cut and SC-cut are two of the most widely used cuts in frequency control, and choosing between them depends on what your application actually needs.

AT-cut crystals

The AT-cut is the most common cut used in crystal oscillators and standard quartz crystals. It offers a good, predictable frequency-versus-temperature curve, is well understood, easy to manufacture, and cost-effective — making it the default choice for the large majority of applications.

SC-cut crystals

The SC-cut (Stress-Compensated cut) is a more specialised cut designed to be far less sensitive to mechanical stress — from mounting, shock, vibration, or the crystal's own drive level. This gives it superior short-term stability, faster warm-up characteristics, and better resistance to acceleration-induced frequency shifts.

Comparing the two

• Stress sensitivity: SC-cut is significantly less affected by mounting stress and vibration than AT-cut.
• Short-term stability: SC-cut generally performs better, which is why it's favoured in the highest-precision OCXOs.
• Warm-up time: SC-cut typically stabilises faster after power-on.
• Cost and availability: AT-cut is cheaper and more widely available; SC-cut is more specialised and costs more.
• Complexity: SC-cut is more difficult to manufacture precisely, reflected in its price.

Which one do you need?

For general-purpose oscillators, standard frequency references, and cost-sensitive designs, AT-cut is the practical choice. For the most demanding applications — high-end OCXOs, precision test equipment, aerospace and defence systems where vibration resistance and fast warm-up matter — SC-cut is worth the additional cost.

Vikronix supplies both cuts

Vikronix supplies quartz crystals in both AT-cut and SC-cut, manufactured through our partnership with Laptech Precision. Browse our Quartz Crystals range or get in touch to discuss which cut fits your application.