1.4848 Oil-Cooled Tray-type Heat Treatment Fixture Suitable for Box-Type Furnaces CFC Fixtures

Box furnace Heat Treatment Fixture & Toolings

Box furnace heat treatment fixtures are load-bearing and support systems designed for box-type resistance furnaces. While this furnace type features a simple structure and is the most widely used, its fixture design requires specialized optimization to address the characteristics of batch production, manual operation, and a relatively static furnace environment.

The core objective of box furnace fixtures is: Within the limited and static furnace chamber space, to achieve rational workpiece placement, efficient heating, uniform heat exposure, and to minimize deformation as much as possible.

I. Core Features

• Static Heating Environment: Unlike continuous furnaces, the atmosphere inside a box-type furnace (mostly air, or protective gas can be introduced) is basically natural convection or slight forced convection, with heat conduction and radiation as the main heat transfer methods. The fixture design must avoid severe obstruction of heat flow.
• Batch Operation and Manual Loading/Unloading: Fixtures need to be frequently taken out of and put into the high-temperature furnace chamber manually or by simple machinery (such as forklifts, hand trucks). Therefore, the fixtures must have a solid structure, moderate weight, and be easy to clamp and handle.
• High Requirements for Versatility and Flexibility: A single box-type furnace often needs to process parts of various sizes and shapes, so its fixtures must have strong adaptability.

II. Main Types and Structural Forms
Fixtures for box-type furnaces are generally relatively simple in structure, emphasizing practicality and durability.
1. Universal Trays and Base Plates

• Structure: Square or rectangular flat plates made of heat-resistant steel plates (e.g., 310S, 330) or castings. Holes can be drilled on the plates to reduce weight and promote air circulation.
• Application: Directly hold workpieces or serve as basic load-bearing platforms for placing other fixtures.
• Design Key Points: Must be extremely flat and thick to prevent severe warping during repeated heating and cooling cycles. Lifting holes or forklift slots are usually provided at the edges.

2. Racks and Supports

• Structure: Multi-layer frames welded from heat-resistant steel bars, tubes, or profiles.
• Application: Used for stacking or placing workpieces in layers (e.g., long shafts, rods, dies), maximizing the utilization of furnace chamber height and facilitating hot air circulation between layers.
• Design Key Points: Layer heights can be adjustable or designed with standard spacing. The structure must be stable to prevent tipping.

3. Special Fixtures and Jigs

• Structure: Simple restraining or supporting devices designed for deformation-prone workpieces (e.g., thin-walled rings, long racks, precision dies).
• Principle: Restrict the free deformation of workpieces during heat treatment through bolts, clamps, or self-weight.
• Examples: Expansion rings to prevent ovalization of ring-shaped parts; multi-point V-shaped supports to prevent bending of long rods.

4. Canned and Box-Type Fixtures (for Protective Atmospheres)

• Structure: Sealed cans or boxes with lids for enclosing workpieces. Protective gases (e.g., nitrogen, argon) can be introduced inside, or solid carburizing media (e.g., carburizers) can be placed.
• Application: Realize simple protective atmosphere heat treatment or chemical heat treatment in ordinary box-type furnaces.
• Material: 310S stainless steel is commonly used, requiring excellent high-temperature sealing performance.

III. Material Selection
Key Considerations: High-temperature strength, oxidation resistance, thermal fatigue resistance, and cost.
Commonly Used Materials:
1. AISI 310S (2520): The most cost-effective option with excellent oxidation resistance, suitable for air furnaces or mild carburizing atmospheres below 950°C.
2. RA 330: Selected for higher temperatures (up to 1150°C), heavier loads, or potential mild carburization risks, offering better strength and longer service life than 310S.
3. Castings (e.g., high-chromium cast iron): Used for manufacturing pads or bracket bases with complex shapes and wear - resistant requirements.
Notes: Plain carbon steel should be avoided in air furnaces as it oxidizes extremely rapidly, resulting in a short service life and severe contamination.

Material Grade Table:

FAQ:

Q: How to give inquiry ?

A: Step 1, please give us some details about your furnace,operating temperature,cooling method,loading weight of your furnace and so on;

Step 2, it's better to provide 3D drawings;

Step 3, when we have enough details, we may design the products drawings and quote accordingly;

Q: When can I get the price?

A: We usually quote within 24 hours after we get your inquiry(Except weekend and holidays). If you are very urgent to get the price, please email us or contact us in other ways so that we can offer you a quote.

Q: When will make delivery ? /What is the delivery Time?

A: -Sample Order: 35 days after receipt of the full payment.

-Stock Order: 10 days after receipt of the full payment

-OEM Order: 30 days after receipt of the deposit.

Q: What's your after-sales service?

A: 1 year warranty for all kinds of products;

If you find any defective accessories first time, we will give you the new parts for free to replace in the next order, as an experienced manufacturer, you can rest assured of the quality and after-sales service.

Q: What's your payment condition?

A: T/T

Payment<=USD10000, 100% in advance. Payment>USD10000, 50% T/T in advance ,balance before shipment.

Q: What is the shipping method?

A: Transported by DHL, UPS, EMS, Fedex,Air freight, sea freight or train freight.