FH® Pit/ Well-Type Furnace Fixtures
Key Benefits
- Complete System Solution
Base tray + stacking baskets + support posts / grids – designed as
an integrated system for stable stacking and optimal gas flow. - Heavy-Load Bearing
Reinforced rib structures and support feet distribute weight evenly
– supports tall stacks of parts or multiple baskets without center
sagging. - Gas Circulation Optimized
Raised feet on base tray + open grid patterns + support post
spacing allow hot gas to flow around all surfaces – uniform heating
from bottom to top. - Anti-Carburization / Anti-Nitriding
High-silicon alloys resist carbon and nitrogen penetration –
extends service life in aggressive atmospheres. - Custom Configuration
Circular or rectangular – precisely matched to your furnace
internal dimensions. Segmented options for large diameters.
System Components
| Component | Function | Key Feature |
| Base Tray | Foundation for entire stack | Raised feet for gas flow, reinforced ribs for load distribution |
| Stacking Baskets | Hold and separate parts | Open grid design, smooth edges, stackable interface |
| Support Posts / Grids | Additional layers between baskets | Custom height, stable stacking interface |
| Top Grid | Secures top layer | Prevents tipping during handling |
Technical Specifications
| Parameter | Value |
| Typical materials | 1.4849, 310S, 1.4828 (by specification) |
| Max. continuous temp. | 1050°C (1.4849) / 950°C (310S) / 1000°C (1.4828) |
| Shape | Circular (standard) or rectangular |
| Base tray feet height | 50 – 200 mm (custom) |
| Support post height | 100 – 500 mm (custom) |
| Max. total load | 500 – 3000 kg (design dependent) |
| Fabrication | Precision welding or investment casting |
| Standard diameters | 600 mm, 800 mm, 1000 mm, 1200 mm (custom available) |
| Expected service life | 300 – 600 cycles (depending on material & atmosphere) |
| Material test certificate (MTC) included with every FH® system
component |
Why Choose FH® Pit/ Well-type Furnace Fixtures?
1. Designed for Pit/ Well-type Furnace Challenges
| Challenge | FH® Solution |
| Heavy stacks (2–3 meters tall) | Reinforced ribs + high creep strength alloy |
| Bottom layer uneven heating | Raised feet + open grid patterns |
| Difficult top access removal | Segmented options for large diameters |
| Thermal cycling stress | Rounded corners + stress-relieved construction |
| Carbon/nitrogen penetration | High-silicon alloys + pre-oxidation |
2. Design Features That Matter
| Feature | Benefit |
| Reinforced rib underside (base tray) | Prevents center sagging under heavy loads |
| Raised support feet | Allows gas flow under bottom layer – uniform heating |
| Open grid pattern on baskets | Maximum gas circulation, minimal thermal mass |
| Precision stacking interfaces | Stable stacking – no tipping |
| Rounded corners (rectangular) | Reduces stress concentration |
| Segmented construction (large diameters) | Easy installation through top opening |
3. Clean Operation
- Pre-oxidized or shot-blasted surface reduces initial scaling
- Smooth weld finishes prevent part damage and scale adhesion
- Parts come out cleaner – reduces post-treatment cleaning
Applications
- Well-type / pit carburizing furnaces
- Well-type carbonitriding furnaces
- Well-type annealing furnaces
- Well-type hardening furnaces
- Well-type tempering furnaces (medium-high temperature)
- Well-type gas nitriding furnaces
- Parts: large gears, shafts, rings, dies, tooling, heavy castings,
long tubes
Genuine Photos of FH® Heat Treatment Fixtures
Material Grade Table
| Heat-resistant Steel |
| / | GB | DIN | ASTM | JIS | Chemical Composition (%) | Maximum Operation Temperature |
| C | Si | Mn | Cr | Ni | Nb/Cb | Mo | Other |
| 1 | ZG40Cr27Ni4 | 1.4823 | HD | SCH11 | 0.30 - 0.50 | ≤2.00 | ≤1.00 | 24.00 - 28.00 | 4.00 - 6.00 | - | ≤0.50 | - | 1050℃ |
| 2 | ZG40Cr22Ni10 | 1.4826 | HF | SCH12 | 0.30 - 0.50 | 1.00 - 2.50 | ≤2.00 | 19.00 - 23.00 | 8.00 - 12.00 | - | ≤0.50 | - | 950℃ |
| 3 | ZG30Cr28Ni10 | - | HE | SCH17 | 0.20 - 0.50 | ≤2.00 | ≤2.00 | 26.00 - 30.00 | 8.00 - 11.00 | - | - | - | 1050℃ |
| 4 | ZG40Cr25Ni12 | 1.4837 | HH | SCH13 | 0.30 - 0.50 | 1.00 - 2.50 | ≤2.00 | 24.00 - 27.00 | 11.00 - 14.00 | - | ≤0.50 | - | 1050℃ |
| 5 | ZG30Cr28Ni16 | - | HI | SCH18 | 0.20 - 0.50 | ≤2.00 | ≤2.00 | 26.00 - 30.00 | 14.00 - 18.00 | - | - | - | 1100℃ |
| 6 | ZG40Cr25Ni20Si2 | 1.4848 | HK | SCH21 | 0.30 - 0.50 | ≤1.75 | ≤1.50 | 23.00 - 27.00 | 19.00 - 22.00 | - | ≤0.50 | - | 1100℃ |
| 7 | ZG30Cr20Ni25 | - | HN | SCH19 | 0.20 - 0.50 | ≤2.00 | ≤2.00 | 19.00 - 23.00 | 23.00 - 27.00 | - | - | - | 1100℃ |
| 8 | ZG40Cr19Ni39 | 1.4865 | HU | SCH20 | 0.35 - 0.75 | ≤2.50 | ≤2.00 | 17.00 - 21.00 | 37.00 - 41.00 | - | - | - | 1020℃ |
| 9 | ZG40Cr15Ni35 | 1.4806 | HT | SCH15 | 0.35 - 0.70 | ≤2.00 | ≤2.00 | 15.00 - 19.00 | 33.00 - 37.00 | - | ≤0.50 | - | 1000℃ |
| 10 | ZG40Cr25Ni35Nb | 1.4852 | HPCb | SCH24Nb | 0.30 - 0.50 | ≤2.00 | ≤2.00 | 24.00 - 28.00 | 33.00 - 37.00 | 0.80 - 1.80 | ≤0.50 | - | 1100℃ |
| 11 | ZG40Cr19Ni39Nb | 1.4849 | - | - | 0.30 - 0.50 | 1.00 - 2.50 | ≤2.00 | 18.00 - 21.00 | 36.00 - 39.00 | 1.20- 1.80 | ≤0.50 | - | 1100℃ |
| 12 | ZG40Cr24Ni24Nb | 1.4855 | - | - | 0.30 - 0.50 | 1.00 - 2.50 | ≤2.00 | 23.00 - 25.00 | 23.00 - 25.00 | 0.80 - 1.80 | ≤0.50 | - | 1050℃ |
| 13 | ZG40Cr25Ni35 | 1.4857 | HP | SCH24 | 0.35 - 0.50 | 1.00 - 2.50 | ≤2.00 | 24.00 - 28.00 | 33.00 - 37.00 | - | ≤0.50 | - | 1100℃ |
| 14 | ZG1Cr20Ni32Nb | 1.4859 | - | - | 0.06 - 0.15 | 0.50 - 1.50 | ≤2.00 | 19.00 - 21.00 | 31.00 - 33.00 | 0.50 - 1.50 | ≤0.50 | - | 1050℃ |
| 15 | ZG45Cr12Ni60 | - | HW | - | 0.35 - 0.75 | ≤2.00 | ≤2.00 | 10.00 - 14.00 | 58.00 - 62.00 | - | - | - | 1100℃ |
| 16 | ZG45Cr18Ni66 | - | HX | - | 0.35 - 0.75 | ≤2.00 | ≤2.00 | 15.00 - 19.00 | 64.00 - 68.00 | - | - | - | 1100℃ |
| 17 | ZG1Cr28Co50 | 2.4778 | - | - | 0.05 - 0.25 | 0.50 - 1.00 | ≤1.50 | 27.00 - 30.00 | ≤1.00 | ≤0.50 | ≤0.50 | Co:48.0 - 52.0 | 1200℃ |
| 18 | ZG30Cr28Co50Nb | 2.4779 | - | - | 0.25 - 0.35 | 0.50 - 1.50 | 0.50 - 1.50 | 27.00 - 29.00 | - | 1.50 - 2.50 | ≤0.50 | Co:48.0 - 52.0 | 1200℃ |
| 19 | ZG40Cr28Ni48W5 | 2.4879 | - | SCH42 | 0.35 - 0.55 | 1.00 - 2.00 | ≤1.50 | 27.00 - 30.00 | 47.00 - 50.00 | - | ≤0.50 | W:4.0 - 5.5 | 1200℃ |
Ordering Process
- Provide furnace internal diameter (or length × width) and usable
depth
- Share part dimensions, batch weight, and operating temperature
- Specify atmosphere (carburizing, nitriding, annealing, etc.)
- FH® proposes complete system design + 3D layout
- Confirm component quantities (base tray + number of baskets +
supports)
- Delivery includes: MTC, inspection reports, stacking diagram, care
guide
FAQ:
Q1: What does a complete FH® well-type furnace fixture system
include?
A: A standard system includes: base tray (with raised feet),
stacking baskets (quantity based on furnace depth), support
posts/grids (for additional layers), and top grid. All components
are designed to work together.
Q2: How many baskets can I stack in my well-type furnace?
A: It depends on furnace depth and part height. FH® calculates this
for you. Example: Furnace depth = 2000 mm, base tray height = 150
mm, clearance = 100 mm → usable height = 1750 mm. If each basket is
250 mm tall, you can stack 7 baskets.
Q3: How do I clean and maintain the fixtures?
A: Every 80–120 cycles, remove fixtures and lightly bead blast
(glass beads, ≤0.3 MPa). Check base tray flatness – if sag exceeds
5 mm per 1000 mm, consider replacement. Do not hammer or
heat-straighten. Avoid carbon steel brushes.
Q4: Can these fixtures be used in a well-type gas nitriding
furnace?
A: Yes. For gas nitriding (500–580°C), 310S is usually sufficient.
If you run both carburizing and nitriding in the same furnace,
1.4849 is more versatile. All fixtures will develop a surface
nitride layer – clean every 50–80 cycles.
Q5: Do you offer spare parts or repair services?
A: Yes. We stock common components. For damaged baskets, we offer
weld repair (if localized) or replacement. Base trays are typically
replaced rather than repaired. Contact us with photos for a repair
assessment.
Q6: What is your warranty?
A: 12 months against manufacturing defects (weld cracks, casting
flaws, material defects). Normal creep, surface
carburization/nitriding, and gradual sagging are considered normal
wear – not covered. Every component comes with MTC and inspection
report.
