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Pit Type Heat Treatment Furnace
COOLDO HEAT TREATMENT EQUIPMENT
Pit Type Heat Treatment Furnace Buyer Page
COOLDO vertical pit type resistance heat treatment furnaces are cycle-production furnaces for processing metal parts in a natural or protective atmosphere. The RJ and RQ series are used for bright annealing, tempering, hardening and other heat-treatment processes for standard parts, carbon steel, alloy steel, magnetic materials and small batches of strip material.
- RJ2 / RQ3
- Model range
- φ500–φ4500 mm
- Custom body diameter
- 650°C / 950°C
- Series temperature
- Gas / Fuel / Electric
- Heating options
RJ2 and RQ3 Pit Furnace Series
Compare the two standard vertical pit furnace ranges by process, temperature and capacity.
RJ2 Series
Resistance well type tempering furnace for batch heat treatment at a rated temperature of 650°C.
- Best for: tempering, annealing and routine heat treatment
- Heating: electric resistance
- Atmosphere: natural or protective atmosphere by configuration
- Listed capacity: 400–1000 kg
RQ3 Series
Pit type gas carburizing furnace for higher-temperature and controlled-atmosphere processing at a rated temperature of 950°C.
- Best for: carburizing, hardening and controlled-atmosphere heat treatment
- Process: gas carburizing
- Atmosphere: configured process gas
- Listed capacity: 50–500 kg
How to Choose a Custom Industrial Pit Furnace
When comparing an industrial pit furnace for sale, confirm more than the headline pit furnace price. A reliable vertical pit furnace manufacturer should size the chamber, loading fixture, heating zones, protective-atmosphere system and cooling arrangement around the actual workpiece and process. COOLDO supplies custom top-loading heat treatment furnaces for shafts, gears, fasteners, tools and other steel parts, including electric resistance pit tempering furnaces, controlled-atmosphere pit annealing furnaces and gas carburizing pit furnaces.
What Is a Pit Type Heat Treatment Furnace?
A pit type heat treatment furnace is vertical batch equipment used for the heat treatment of metal materials. Its wellhead-like structure has a top opening for loading and removing workpieces. It can be used for annealing, normalizing, quenching, tempering and other thermal processes that improve hardness, strength, wear resistance and other mechanical properties.
- What is it?
- A vertical, top-loading cycle-production furnace for metal heat treatment.
- What is it used for?
- Annealing, tempering, hardening, normalizing, quenching and carburizing.
- Which atmospheres?
- Natural atmosphere or a configured protective atmosphere such as nitrogen or process gas.
- Which workpieces?
- Steel parts, shafts, gears, fasteners, springs, tools and other long or batch-loaded parts.
Furnace Body
The body uses high-temperature-resistant materials to maintain stability and sealing. Its top opening supports insertion and removal of long, heavy or batch-loaded workpieces.
Heating Elements
Resistance heating elements convert electrical energy into heat and transfer it to the chamber and load. Heating zones are selected for the required process.
Control System
Temperature and power controllers monitor and adjust furnace conditions so the programmed heat-treatment cycle can be followed with good batch repeatability.
Cooling System
After heating and soaking, the configured cooling system reduces the workpiece temperature according to the required process.
Pit Type Heat Treatment Furnace Specifications
RJ2 Resistance Well Type Tempering Furnace
| Model | Power | Phase | Voltage | Temperature | Working zone | Capacity |
|---|---|---|---|---|---|---|
| RJ2-25-6 | 25 kW | 3 | 380 V | 650°C | Ø400×500 mm | 400 kg |
| RJ2-35-6 | 35 kW | 3 | 380 V | 650°C | Ø500×650 mm | 500 kg |
| RJ2-55-6 | 55 kW | 3 | 380 V | 650°C | Ø700×900 mm | 750 kg |
| RJ2-75-6 | 75 kW | 3 | 380 V | 650°C | Ø950×1200 mm | 1000 kg |
RQ3 Pit Type Gas Carburizing Furnace
| Model | Power | Phase | Voltage | Temperature | Working zone | Capacity |
|---|---|---|---|---|---|---|
| RQ3-25-9 | 25 kW | 3 | 380 V | 950°C | Ø300×450 mm | 50 kg |
| RQ3-35-9 | 35 kW | 3 | 380 V | 950°C | Ø300×600 mm | 100 kg |
| RQ3-60-9 | 60 kW | 3 | 380 V | 950°C | Ø450×600 mm | 150 kg |
| RQ3-75-9 | 75 kW | 3 | 380 V | 950°C | Ø450×900 mm | 220 kg |
| RQ3-90-9 | 90 kW | 3 | 380 V | 950°C | Ø600×900 mm | 400 kg |
| RQ3-105-9 | 105 kW | 3 | 380 V | 950°C | Ø600×1200 mm | 500 kg |
Note: Final power, chamber size, atmosphere system, cooling arrangement and capacity must be confirmed against the workpiece and heat-treatment cycle.
Applications of a Controlled-Atmosphere Pit Furnace
This industrial pit furnace is used for bright annealing, hardening, tempering, stress relieving, quenching, normalizing and carburizing of long or heavy steel parts.
- Fasteners
- Springs
- Gears
- Tools and Dies
- Bearings
- Chains
- Shafts
- General Steel Parts
Key Technical Features
- Vertical top-loading chamber with uniform multi-zone heating
- High-temperature-resistant furnace body for stability and sealing
- Gas, fuel or electric heating configurations
- Natural, nitrogen, endogas or other configured atmospheres
- Accurate temperature and power control
- Configurable cooling system
- PLC/HMI control and optional process data logging
- Custom chamber size and loading fixtures
Pit Furnace Production and Installation Photos
Frequently Asked Questions About Pit Type Heat Treatment Furnaces
Technical answers for buyers comparing RJ2, RQ3 and custom vertical pit furnace configurations.
What is a pit type heat treatment furnace?
It is a vertical, top-loading batch furnace for heat treating metal parts. Its wellhead-like chamber is suitable for long parts, heavy fixtures and batch loads lowered into the furnace from above.
How do I choose between an RJ2 and RQ3 pit furnace?
Choose RJ2 for electric-resistance processing at a rated 650°C. Choose RQ3 for carburizing and higher-temperature processes at a rated 950°C. Final selection depends on the material, process curve, atmosphere and batch load.
Which heat-treatment processes can this furnace perform?
Depending on the series and configuration, it can support annealing, bright annealing, tempering, hardening, normalizing, quenching, stress relieving and carburizing.
What materials and parts can be processed?
Typical loads include carbon steel and alloy steel components, shafts, gears, bearings, fasteners, springs, chains, tools, magnetic materials and small batches of strip material.
Can it operate in natural and protective atmospheres?
Yes. It can operate in a natural atmosphere or with a configured protective-atmosphere system. Nitrogen, endogas or another process gas may be selected according to the material and surface requirement.
What configuration is suitable for bright annealing?
Bright annealing normally requires a sealed muffle or protective chamber, controlled gas flow and an atmosphere selected for the alloy and required surface finish.
What temperature and chamber sizes are available?
RJ2 models are rated at 650°C and RQ3 models at 950°C. Listed working zones range from Ø300×450 to Ø950×1200 mm, with custom furnace body diameters from 500 to 4500 mm.
How does the temperature-control system work?
Temperature and power controllers monitor and adjust furnace conditions so the programmed heat-treatment cycle can be followed. Multi-zone control, PLC/HMI operation and data logging can be configured.
How are workpieces loaded and cooled?
Workpieces are placed in a basket or fixture and loaded through the top opening. After heating and soaking, the load is cooled according to the required process before unloading.
Can COOLDO manufacture a custom pit furnace?
Yes. Chamber diameter and depth, capacity, heating method, fixtures, atmosphere, cooling, controls and data logging can be engineered around the customer's process.
What information is required for an accurate quotation?
Provide the workpiece material, dimensions and weight, batch capacity, heat-treatment process, temperature curve, atmosphere, daily output, power supply and installation location.
Need a Custom Pit Furnace Configuration?
Send the workpiece, process, temperature, atmosphere and capacity requirements to receive an engineered recommendation.