skip to Main Content


Muffles and retorts

NICRO Gallery 1
NICRO Gallery 2
NICRO Gallery 3
NICRO Gallery 4
NICRO Gallery 5
NICRO Gallery 6
NICRO Gallery 7
NICRO Gallery 8
NICRO Gallery 9
NICRO Gallery 10
NICRO Gallery 11
NICRO Gallery 12
NICRO Gallery 13
NICRO Gallery 14
NICRO Gallery 15
NICRO Gallery 16
NICRO nav 1
NICRO nav 2
NICRO nav 3
NICRO nav 4
NICRO nav 5
NICRO nav 6
NICRO nav 7
NICRO nav 8
NICRO nav 9
NICRO nav 10
NICRO nav 11
NICRO nav 12
NICRO nav 13
NICRO nav 14
NICRO nav 15
NICRO nav 16

The muffle is an essential part of heat treatment furnaces used for case-hardening, tempering, brazing, annealing, carbonitriding, quenching, hyper-quenching, sintering, bright annealing or other similar industrial processes. During these treatments, the muffle may be subject to intense thermal, mechanical or chemical stress due to the active atmosphere inside the furnace.

Muffle furnaces can be box-shaped or cylindrical. The most common furnaces have a parallelepiped chamber, although furnaces with arched or vaulted roof are also common. Moreover, we can also find tilting tube, openable and rotary furnaces.

The interior of rotary furnaces is fitted with the retort, the most important element of the furnace, which isolates the atmosphere and creates the part transit movement, usually towards tempering.

Similarly to muffles in conveyor furnaces, the active atmosphere in some chamber furnaces must be contained in a metal muffle. The thermal stress generated in the heating and rapid cooling zones requires special adaptations, as well as combinations of alloys suited to this difficult environment.

The great experience grown in more than thirty years in the construction and knowledge of these products grants Nicro as an excellent partner, as shown by the collaboration relationship with some of the most important worldwide companies in the sector.

Thanks to qualified workers and a continuous updated plant and methodologies, such as the introduction of the new Force Tig welding technology, we can cope with any request.

In case we have not the constructive drawing, moreover, through the reverse engineering we can detect dimensions and all data required to proceed for the construction of a new muffle.


Aisi 321 (Werkstoff 1.4541)
Aisi 309 (Werkstoff 1.4828)
Aisi 310 (Werkstoff 1.4845)
Avesta 253MA (Werkstoff 1.4835)
Nicrofer 6025HT (Werkstoff 2.4633)
Inconel 600 (Werkstoff 2.4816)
Inconel 601 (Werkstoff 2.4851)
Incoloy 800H

Do you have
a special project requirement?

Contact Us

Other products

Customised components

Find out more

Components for the Oil & Gas sector

Find out more

Scrubbers for marine sector

Find out more

Heat treatment equipment

Find out more

Radiant tubes

Find out more

Convection Fans

Find out more

Bells, bases and diffusers for furnaces

Find out more

Back To Top