Box Furnace (Muffle Furnace)
1200°C to 1800°C

The terms "box furnace" and "muffle furnace" are often used interchangeably. Strictly speaking, a muffle furnace refers specifically to furnaces where the heating elements are separated from the working chamber by a refractory muffle — preventing combustion gases from contacting the sample. Modern electric box furnaces achieve the same separation by embedding heating elements in the chamber walls. In industry, both terms describe the same category of rectangular-chamber electric resistance furnaces.

Select a temperature series with a maximum rating at least 50–100°C above your required process temperature. This provides headroom for temperature uniformity variation and extends element life. For example, if your process requires 1350°C, the 1400°C SiC series is the correct choice rather than running a 1200°C furnace at its limit. If you are unsure, contact our technical team with your process temperature, atmosphere, and sample details — we will recommend the optimal series.

Standard box furnaces are designed for air atmosphere operation. Atmosphere-compatible versions with sealed chambers, gas inlet/outlet ports, and appropriate sealing systems are available as a customisation option. These can operate with inert gases (N₂, Ar) or mild reducing atmospheres (N₂/H₂ forming gas at low H₂ concentrations). For aggressive reducing atmospheres or vacuum operation, we recommend our dedicated atmosphere furnace or vacuum furnace product lines.

Heat-up rates depend on the temperature series, chamber size, and load mass. As a general guide: 1200°C series furnaces typically reach maximum temperature in 30–60 minutes from cold; 1400°C SiC series in 45–75 minutes; and 1700°C/1800°C MoSi₂ series in 60–90 minutes. Maximum programmable ramp rates are typically 10–20°C/min for smaller chambers. Actual rates with sample load will be lower. Specific heat-up curves are available on request for each model.

MoSi₂ heating element service life depends heavily on operating temperature and thermal cycling frequency. Under normal laboratory conditions (operating at 80–90% of maximum rated temperature, with controlled ramp rates), MoSi₂ elements typically last 1,000–3,000 operating hours. Elements operated continuously at maximum temperature or subjected to rapid thermal cycling will have shorter service lives. Replacement elements are stocked and available for all Brother Furnace models.

The drop-bottom (bottom-opening) door configuration is specifically designed for quenching operations. When the bottom door opens, the sample drops directly into a quench tank positioned below the furnace. This minimises the time between furnace and quench medium, which is critical for achieving the desired metallurgical properties. Brother Furnace drop-bottom models are available with motorised door actuators and programmable door-open sequences integrated into the temperature controller.

Yes. Standard controllers on all Brother Furnace box furnaces support 30-segment programmable temperature profiles, allowing you to define complex heat treatment cycles with multiple ramp rates, dwell times, and controlled cooling steps. Advanced controller options support multiple stored programs (up to 30 programs on some models), USB data logging, and PC software for program management and real-time monitoring. This is particularly valuable for regulated industries requiring documented process records.

All Brother Furnace box furnaces carry CE certification (EU Declaration of Conformity) covering the Low Voltage Directive and Electromagnetic Compatibility Directive. Our manufacturing facility is ISO 9001:2015 certified. Products are RoHS compliant. For customers in specific regulated markets, we can provide additional documentation including material certificates, calibration certificates, and factory acceptance test (FAT) reports.

Standard models are typically available for shipment within 2–4 weeks. Custom configurations — including non-standard chamber dimensions, atmosphere capability, or special control systems — generally require 4–8 weeks from order confirmation. Complex projects with multiple customisations or special materials may require up to 10–12 weeks. Lead times are confirmed at the time of order and are included in the order acknowledgement.

Yes. All Brother Furnace box furnaces ship with comprehensive installation and operation manuals. Remote commissioning support via video call is available at no charge. For customers requiring on-site installation and commissioning, our service engineers can be dispatched internationally — please enquire at the time of order for availability and pricing. We also provide operator training documentation and safety data sheets for all models.