Φ9/18 MoSi2 Heating Elements: High-Power, Heavy-Duty

The Φ9/18 element (9 mm hot zone, 18 mm cold end) is the heavy lifter. Its thick cross-section carries up to ~500 A, delivering the high total wattage needed for large chambers and fast heat-up without overloading any single leg.

Specification at a glance

Parameter	Φ9/18 value
Hot-zone diameter	9 mm
Cold-end diameter	18 mm
Typical max current (air, steady state)	~500 A
Common grades	EQ1700, EQ1800, EQ1850
Typical use	Large chambers, high-throughput sintering, metallurgy, fast heat-up furnaces

Current is a planning ceiling set by your transformer and lead-wire rating. See the current-limits table for the full diameter series.

When to step up to Φ9/18

If a Φ6/12 set would have to run near its surface-load ceiling to hit your power target, go to Φ9/18 instead. A larger diameter runs cooler per cm² at the same wattage, which is the reliable way to get more power at temperature — not by overloading a smaller element. That matters for powder-metallurgy and large sintering furnaces where throughput drives the spec.

Grade pairing

Pair Φ9/18 with the grade your hold temperature demands: EQ1700 for everyday high-temperature firing, EQ1800 for ceramics and dental-grade headroom, or EQ1850 when the chamber must hold 1750–1800°C. The grade temperature explainer helps you fix that number.

About the author: Prepared by the HeatingDriver Application Engineering team, engineers with nearly 20 years of experience in high-temperature elements for industrial and research furnaces. Browse our MoSi2 elements or send us your power requirement.

See the full MoSi2 range or contact us to size a high-power element set.

Why specify with HeatingDriver

Why specify with HeatingDriver — HeatingDriver is a manufacturer and exporter of MoSi2 (molybdenum disilicide) heating elements with nearly 20 years of experience. We supply EQ1700U / EQ1800U / EQ1850U grades for 1700–1850°C, free drawing review, custom sizes and shapes, and technical support for furnace builders worldwide. Browse our MoSi2 heating elements.

What are Φ 9/18 MoSi2 elements?

Φ 9/18 has a 9 mm hot zone and 18 mm cold end, the high-power, heavy-duty size for large furnaces and high loads.

Where are Φ 9/18 elements used?

They suit large ceramic, metallurgy and glass furnaces that need maximum power at 1700–1850°C.

What grades come in Φ 9/18?

Φ 9/18 elements are available in EQ1700U, EQ1800U and EQ1850U grades for the full 1700–1850°C range.

What surface load applies?

Heavy-duty Φ 9/18 elements use a MoSi2 surface load of 4–9 W/cm², scaled up by the large hot-zone area.