News · 2026-05-09
Surface Load Guide for SiC and MoSi2 Heating Elements
Technical Video
Surface Load Guide for SiC and MoSi2 Heating Elements
A short technical video explaining practical surface load checks for SiC and MoSi2 heating elements.
Watch on YouTubeSurface load is a practical selection point for high-temperature heating elements. It should be reviewed with furnace structure, atmosphere and operating temperature rather than treated as a fixed value for every furnace.
SiC surface loading
For Lasting SiC elements, recommended surface loading is 3-8 W/cm² for furnace design when longer service life is the target. In hydrogen or ammonia conditions, operation below 1300℃ with surface loading below 5 W/cm² is recommended.
MoSi2 surface loading
| Furnace temperature | Recommended hot-zone surface load |
|---|---|
| 1400℃ | <18 W/cm² |
| 1500℃ | <15 W/cm² |
| 1600℃ | <12 W/cm² |
| 1650℃ | <10 W/cm² |
| 1700℃ | <8 W/cm² |
For long service life, surface load should be selected together with furnace structure, atmosphere and operating temperature.
Buyer checklist
- Element material: SiC or MoSi2
- Furnace temperature and atmosphere
- Element shape and dimensions
- Voltage, power, current and resistance if available
- Continuous or intermittent operation
Surface load RFQ review table
Surface load is calculated from element power and hot-zone surface area, but the acceptable value still depends on furnace design. Send the following details when asking Henan Lasting to review a SiC or MoSi2 heating element specification.
| RFQ detail | Why it changes surface load review | Buyer note |
|---|---|---|
| Element material and shape | SiC rods, U/W SiC elements and MoSi2 elements use different hot-zone geometry. | Attach a drawing or old element photo if the shape is uncertain. |
| Diameter and hot zone length | These define the heated surface area used in W/cm² review. | Do not use overall length as the hot-zone length. |
| Voltage, power and resistance | Electrical data shows the actual heat load and whether replacement elements need matching. | For used SiC elements, measured current and voltage records are useful. |
| Furnace atmosphere and duty cycle | Nitrogen, hydrogen, vacuum, rapid cycling or dusty conditions can require lower practical loading. | Include continuous or intermittent operation details. |
| Element spacing and furnace chamber | Radiation obstruction and tight spacing can create local hot spots. | Send furnace drawings when changing element quantity or layout. |
Use the RFQ form or compare SiC heating elements and MoSi2 heating elements before sending a quote request.
FAQ
What surface loading is recommended for SiC heating elements?
Recommended SiC surface loading is 3-8 W/cm² for furnace design when aiming for longer service life.
What surface load is recommended for MoSi2 at 1700℃?
Recommended MoSi2 hot-zone surface load is below 8 W/cm² at 1700℃.
What data is needed to review surface load before buying heating elements?
Send element material, diameter, hot zone length, furnace temperature, atmosphere, voltage, power, quantity, operating cycle and whether the project is a new furnace or replacement.
How can buyers reduce surface load risk in a SiC furnace?
Review element diameter, hot-zone length, power, spacing, atmosphere and duty cycle. Lower surface load, matched resistance and suitable element spacing usually reduce hot spots and fast aging risk.