Custom 600 × 600 × 900 Heat Treatment Fixture for Bolts in a Vertical Vacuum Quench Furnace

Customer Case Study | Fixture Design for an Italian Customer
Customer Location: Italy
Application: Bolts Heat Treatment
Furnace Type: Vertical Vacuum Quench Furnace
Working Temperature: 900°C
Cooling Method: Oil Cooling
Maximum Furnace Load: 600 kg
Loading Space: 600 × 600 × 900 mm
Designed by: Wuxi Junteng Fanghu Alloy Technology Co., Ltd. (FH® Alloy)

Project Overview
FH® Alloy previously proposed a vertical loading solution for an Italian customer processing bolts in a vertical vacuum quench furnace. After reviewing the suggested loading method, the customer accepted the concept and asked FH® Alloy to proceed with the fixture design.
The customer provided product information, loading requirements, furnace size, and preferred stacking method. Based on these requirements, FH® Alloy designed:

• a 600 × 600 × 50 mm base tray,
• a 600 × 600 × 900 mm multi-layer fixture frame,
• matching middle trays with wire mesh,
• and several wire welded grids and spacer sets for flexible loading.

The goal was to create a fixture system that could keep the bolts standing vertically, improve loading efficiency, and fit the furnace working space while meeting the process conditions of 900°C oil quenching.

Customer Requirements
The customer wanted a fixture suitable for loading bolts in a stable vertical arrangement.
The main requirements included:

• One base tray with wire mesh
• Five middle trays with wire mesh
• Multiple wire welded grids
• Different spacer heights to adjust the distance between trays
• A loading design capable of processing approximately 5 layers of bolts per batch
• Fixture dimensions suitable for a 600 × 600 × 900 mm vertical furnace space
• A structure that can help keep the bolts vertical during loading and heat treatment

The customer also requested FH® Alloy to provide a simulated loading drawing showing how the bolts could be arranged inside the fixture.

Project Design Inputs

Based on the customer’s information, the design conditions were as follows:

Engineering Challenge
This project was not simply about making a basket or tray. The main challenge was to design a complete modular loading fixture system that would satisfy both process requirements and handling efficiency.

The design needed to solve several key problems:
1. Keeping the Bolts Vertical
The customer wanted the bolts to remain in a stable upright position during loading and heat treatment. This required a structure that could support the bolt body and control the spacing between parts.
2. Flexible Layer Spacing
Because different bolt sizes or process needs may require different vertical spacing, the fixture needed to allow adjustable distances between trays.
3. Efficient Use of Furnace Space
The furnace loading zone was limited to 600 × 600 × 900 mm, so the fixture had to maximize usable loading capacity while remaining easy to assemble and handle.
4. Suitability for High Temperature and Oil Quenching
The fixture would work in a vacuum heat treatment process at 900°C followed by oil cooling, so the structure had to be suitable for repeated thermal cycling and practical production use.

FH® Alloy’s Design Solution
Based on the customer’s request and the proposed loading concept, FH® Alloy developed a modular fixture design consisting of trays, grids, spacers, and a structural frame.
1. Base Tray Design
FH® Alloy designed a 600 × 600 × 50 mm base tray as the bottom support platform.
The base tray was designed to:

• provide stable bottom support,
• match the customer’s requested loading footprint,
• integrate with wire mesh,
• and serve as the foundation for the multi-layer loading structure.

This base tray forms the first key component of the fixture system.

2. Middle Tray Design
The system also includes 5 middle trays, each designed with wire mesh.
These trays help create layered loading positions and allow multiple levels of bolts to be processed in one furnace cycle.
The middle trays were designed with the following objectives:

• stable support for parts,
• good load distribution,
• easy stacking and assembly,
• and compatibility with adjustable spacer heights.

3. Wire Welded Grids for Vertical Positioning
To keep the bolts vertical, the customer requested wire welded grids in different mesh sizes.
FH® Alloy incorporated this requirement into the design and considered the following grid options:

• 10 × 10 mm
• 15 × 15 mm
• 20 × 20 mm

These grid options give flexibility according to the bolt size and the degree of positioning required.
The customer indicated that each layer may require 1 or 2 wire grids, with 1 grid preferred in order to keep the loading method as simple and efficient as possible.

4. Adjustable Spacer Sets
To make the fixture more versatile, FH® Alloy designed the system with multiple spacer height options between trays.
The spacer sets include:

• 50 mm
• 100 mm
• 150 mm
• 200 mm

This modular spacer concept allows the customer to adjust the tray distance according to the dimensions of the bolts and the required loading density.
It also improves the fixture’s flexibility for future production changes.

5. Overall Fixture Structure
After considering the tray layout, grid positioning, and spacing requirements, FH® Alloy completed the design of the full 600 × 600 × 900 mm fixture frame.
This structure was developed for use in a vertical vacuum quench furnace and is intended to support multi-layer loading inside the furnace working zone.
The overall structure offers:

• a compact vertical arrangement,
• layered product loading,
• stable tray support,
• compatibility with wire mesh and grids,
• and efficient use of the furnace height.

From Customer Request to 3D Design
This project demonstrates FH® Alloy’s ability to transform a customer’s operating concept into an engineered fixture solution.
The design process followed a practical workflow:
Customer Loading Request
→ Product Information Review
→ Furnace Space Confirmation
→ Tray & Grid Structure Design
→ Loading Simulation
→ 3D Drawing Preparation
The customer first shared the required loading concept and sample product information. FH® Alloy then converted these requirements into a practical fixture design, including the base tray drawing and the full 3D fixture structure.
This type of engineering support is especially valuable for customers who need more than simple build-to-print manufacturing.

Loading Concept for Bolts
The fixture was designed around the customer’s requirement to process approximately 5 layers of bolts in one batch.

The loading concept includes:

• bolts arranged vertically,
• trays stacked in layers,
• grids used to guide or retain the bolt position,
• and adjustable spacing between each layer.

This approach can help improve:

• loading consistency,
• part arrangement,
• space utilization,
• and furnace batch efficiency.

Project Specification Summary

Why This Project Matters
This case is a good example of how fixture design must be based on the actual product, furnace size, and loading method, not only on external dimensions.
For heat treatment of bolts and similar fasteners, an effective fixture must consider:

• part stability,
• stacking efficiency,
• thermal process compatibility,
• and ease of loading/unloading.

By designing both the tray structure and the complete fixture frame, FH® Alloy helped the customer move from a general loading request to a practical engineered solution.

Custom Heat Treatment Fixture Design by FH® Alloy
Wuxi Junteng Fanghu Alloy Technology Co., Ltd. (FH® Alloy) specializes in the design and manufacture of customized furnace tooling and heat-resistant alloy fixtures, including:

• Heat Treatment Fixtures
• Furnace Baskets
• Base Trays
• Middle Trays
• Wire Mesh Fixtures
• Vacuum Furnace Fixtures
• Oil Quench Furnace Tooling
• Stackable Heat Treatment Frames

We can support customers from:
Loading Concept → Engineering Design → 3D Drawing → Manufacturing
Whether you already have a complete drawing or only a process requirement, FH® Alloy can help develop a practical fixture solution.

Need a Custom Fixture for Bolts or Fasteners?
If you are processing bolts, screws, fasteners, or similar parts in a vacuum furnace or other industrial heat treatment equipment, FH® Alloy can help design custom trays and fixture systems based on your requirements.

Useful information for design includes:

• product drawing or sample,
• furnace type,
• furnace loading space,
• maximum load,
• working temperature,
• cooling method,
• required loading quantity,
• and preferred loading orientation.

FH® Alloy can then provide a customized design and manufacturing solution to match your actual production needs.

About FH® Alloy
Wuxi Junteng Fanghu Alloy Technology Co., Ltd. (FH® Alloy) is a manufacturer of customized heat treatment fixtures, radiant tubes, furnace rollers, centrifugal cast components, and heat-resistant alloy parts for industrial furnace applications.

We focus on providing practical engineering solutions for customers who need reliable high-temperature tooling and custom furnace components.

Custom Design | Custom Manufacturing | Heat-Resistant Alloy Solutions

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