Gelenk-Manipulator für Körbe
Gelenk-Manipulator für Körbe
CATEGORY 05
SAFE HANDLING OF HOT WORKPIECES AFTER HARDENING: HEAT PROTECTION AND WARPING PREVENTION
The most dangerous moment in heat treatment is handling the hot batch. Workpieces leave the furnace at several hundred degrees, quenching is time-critical, and every movement carries a risk of burns and injury.
At the same time, this very moment determines the component quality: uneven positioning, vibrations, and uncontrolled quenching cause warping. Safety and quality therefore depend on the same process step: the handling of the hot batch.
A heat-resistant, guided lifting aid solves both problems simultaneously: It keeps the operator at a safe distance from the radiant heat and guides the load smoothly and without swinging. Zeilhofer Handling Technology from Holzkirchen has been developing precisely these kinds of solutions for the metal industry for 25 years.
CHAPTER 1
Understanding temperatures: What you're dealing with
Anyone who wants to handle hot workpieces safely needs to know the temperatures of the individual process steps. These determine which fixtures, protective measures, and materials are necessary.
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800–1050 °C = Austenitizing in a hardening furnace
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150–300 °C = after quenching
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150–600 °C = Tempering
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up to 80 °C = limit for standard grippers
CHAPTER 2
Burn and injury protection
01 Create distance
A guided lifting aid keeps the operator 2 to 3 meters away from the radiant heat. No manual handling of the hot load.
02 Heat shields
Shielding between the batch and the operator station reduces radiant heat directly at the workplace.
03 Remote-controlled grippers
The shutter opens and closes via thermally decoupled control; the operator does not touch anything hot.
04 Personal Protective Equipment
Heat-resistant gloves, visor and apron complete the technical safety measures according to DGUV regulations.
CHAPTER 3
Avoid delays: Ensure quality
How delays occur
Warping is caused by uneven heating and cooling as well as by mechanical stress on the workpieces. Slippage in the rack, impacts during transfer, and uneven immersion in the quenching bath are typical causes.
How handling reduces delay
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Uniform, stable positioning of the workpieces in the charging rack
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Vibration-free, pendulum-free process without shocks
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Controlled, even lowering into the quenching bath
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Reproducible movement sequences instead of manual fluctuations
The result: less waste, more consistent hardness results and reduced post-processing effort.
CHAPTER 4
Properly lay out heat-resistant mountings
Staggered according to temperature
Up to 80 °C: Standard gripper
Up to approx. 400 °C: High-temperature coatings made of aramid or silicate
Above 400 °C: heat-resistant stainless steels such as 1.4828
Pneumatics: thermally decoupled, heat-resistant PTFE hoses
Resistance to the environment
Salt spray and oil vapor are added during the hardening process. The fixtures and mechanics are made salt- and oil-tight to ensure the lifting aid remains reliable for years.
CHAPTER 5
Standards and testing obligations
Occupational safety in the hardening shop is legally regulated. Zeilhofer designs lifting aids according to the applicable standards and documents their conformity.
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Industrial Safety Ordinance for the Operation of Work Equipment
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DGUV regulations for recurring inspections (UVV)
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Machine safety according to EN ISO 12100
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Safety-related control according to EN ISO 13849 PL d
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CE conformity with complete technical documentation
CHAPTER 6
From security concept to solution
01 Hazard analysis
Recording of temperatures, batches and risks on your furnace line on site.
03 Engineering
Safety-compliant design, FEM, control according to EN ISO 13849, manufacturing in Germany.
02 Protection concept
Design of distance, heat shields, recordings and PPE requirements.
04 Acceptance and training
Safety inspection, commissioning and operator training by our own technicians.
CHAPTER 7
References: 25 years of custom solutions
More than two and a half decades of experience in the metal industry make Zeilhofer HHT a proven partner for hardening plants and heat treaters in Germany and Europe.
What distinguishes Zeilhofer solutions?
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ISO 9001 certified quality management
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TISAX Level 2 with prototype protection for confidential customer projects
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Heat-resistant components for oven removal in the standard range
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Non-oscillating lifting axes with a load capacity of up to 1,200 kg
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Engineering and service from Holzkirchen, no outsourcing chains
FAQ / Q&A
FREQUENTLY ASKED QUESTIONS
01 How heavy are the charging racks in the hardening shop?
Empty: 30 to 150 kg. Fully loaded, charging racks and annealing baskets reach 300 to 800 kg, and in large chamber furnaces over 1,000 kg. The ZH90 lifting axis loads up to 1,200 kg without pendulum action.
02 How hot can a sample be when removed from the hardening furnace?
Standard grippers up to 80 °C. High-temperature supports made of aramid or silicate are used for furnace removal (200 to 400 °C), special stainless steel holders for batches above 500 °C.
03 Can a lifting aid prevent distortion of the workpieces?
Yes. Pendulum-free, low-vibration handling prevents slippage in the rack and ensures a uniform position in the oven. This reduces warping and uneven hardening results.
04 Is a lifting axis suitable for the path between the furnace and the quenching bath?
Yes. For time-critical transfers, short, oscillation-free travel distances are crucial. A lifting axis or a jointed manipulator with a heat-resistant mount guides the batch quickly and smoothly.
05 What maintenance is required for lifting aids in the hardening shop?
Annual safety inspections according to DGUV Regulation 54 are mandatory. Due to heat and salt or oil mist, Zeilhofer recommends a visual and functional inspection every six months. Heat-resistant hoses are replaced every 24 to 36 months.
06 Are protective gas and vacuum furnace systems also serviced?
Yes. Zeilhofer supplies charging solutions for chamber furnaces, pusher furnaces, vacuum and protective gas systems. The lifting aid handles the charging racks before and after the furnace.
READ MORE
FURTHER GUIDES ON THIS TOPIC
In-depth guides on related topics in handling technology.
PRODUCT
ZH90 lifting axle in use
HEAVY INDUSTRY
Forged and cast parts handling
SPECIAL CONSTRUCTION
Special machine construction
NEXT STEP
YOUR INDIVIDUAL HARDENING SPECIAL SOLUTION
Talk to our engineers about your loading and handling requirements. We analyze batches, temperatures, cycle times, and furnace interfaces and develop a custom machine that fits perfectly. Made in Germany, ISO 9001 and TISAX Level 2 certified, free consultation.