Stainless Steel Vs Tool Steel Flat & Round Bar Sizes：What Are The Standard Sizes?

In the world of industrial materials, stainless steel and tool steel are two highly valued categories of steel products. Both are available in different shapes such as sheets, plates, flat bars, and round bars, each catering to specific applications. Among these, flat bars and round bars are the most common semi-finished forms, widely purchased by wholesalers, stockists, and international traders.

While stainless steel offers excellent corrosion resistance and aesthetic appeal, tool steel is engineered for hardness, toughness, and performance under demanding working conditions. But when it comes to procurement, a frequent question arises: What are the standard sizes for stainless steel and tool steel flat & round bars?

This article provides a comprehensive comparison, highlights the typical dimensional ranges, and explains why sourcing from FCS Tool Steel ensures reliability, competitive pricing, and bulk supply advantages.

1. Understanding Flat & Round Bars

Before diving into specific sizes, let’s briefly outline what flat and round bars are:

1. Flat Bars:Rectangular sections used in construction, tooling, structural frameworks, and machine parts. Available in hot rolled or precision ground finishes.
2. Round Bars: Cylindrical steel bars used for machining into shafts, fasteners, gears, molds, and cutting tools. They come in hot rolled, forged, or precision ground conditions.

Both forms are available in stainless and tool steel, but their standard thickness, diameter, width, and length ranges differ depending on grade and application.

2. Standard Stainless Steel Flat Bar Sizes

Stainless steel flat bars are typically supplied in 440C, 420SS, and 420H grades, with good corrosion resistance and high strength.

Common Size Ranges:

1. Thickness: 3 mm – 60 mm
2. Width: 20 mm – 300 mm
3. Length: 3 m, 6 m, or custom cut lengths

Tolerances:

1. Hot rolled: looser tolerances, economical for construction

2. Cold drawn/ground: tighter tolerances, suitable for precision parts

Applications:

1. Architectural frameworks and railings
2. Food processing and chemical plants
3. Marine applications
4. General machine fabrication

3. Standard Stainless Steel Round Bar Sizes

Stainless steel round bars are widely used for shafts, fasteners, and turned parts where corrosion resistance is essential.

Common Diameter Ranges:

1. Hot Rolled/ Forged Round Bar: Ø 10 mm – Ø 600 mm
2. Cold Drawn Round Bar: Ø 4 mm – Ø 100 mm
3. Length: 3 m – 6 m standard, cut-to-size available

Applications:

1. Pump shafts, fasteners, and bolts
2. Marine hardware
3. Precision machine components

4. Standard Tool Steel Flat Bar Sizes

Tool steel flat bars are engineered for performance after heat treatment. They are available in grades like D2 (1.2379), H13 (1.2344), P18, O1, and M2, each designed for different tooling applications.

Common Size Ranges:

1. Thickness: 6 mm – 100 mm
2. Width: 30 mm – 400 mm
3. Length: 2 m – 6 m (with custom options available)

Features:

1. Often supplied as ground flat stock with precise tolerances
2. Delivered in annealed or pre-hardened condition

Applications:

1. Dies, punches, and cutting tools
2. Plastic mold bases
3. High-performance wear-resistant components

5. Standard Tool Steel Round Bar Sizes

Tool steel round bars are essential in die and mold making, hot and cold working tools, and machine components.

Common Diameter Ranges:

1. Hot Rolled/ Forged: Ø 16 mm – Ø 800 mm
2. Cold Drawn/ Precision Ground: Ø 4 mm – Ø 100 mm
3. Length: 2 m – 6 m, often customized for toolmakers

Applications:

1. Shafts, gears, and cutting tools
2. Extrusion dies and forging dies
3. High-speed cutting tools

6. Stainless Steel vs Tool Steel: Dimensional Comparison

This comparison shows that stainless steel excels in environments where corrosion resistance is critical, while tool steel is unmatched for strength, hardness, and tooling performance.

7. Why Choose FCS Tool Steel for Stainless & Tool Steel Bars

For wholesalers, stockists, and international traders, consistency of supply and dimensional accuracy matter as much as steel quality. This is where FCS Tool Steel Factory stands out.

FCS Product Advantages:

Comprehensive Inventory

Stainless steel grades (440C, 420SS, 420H) and tool steels (D2 / 1.2379, H13 / 1.2344, P18, O1, M2, etc.) available in flat and round bar forms.

Dimensional Range

1. Stainless flat bars: 8–45/50-500 mm thick, 50–1000/50-1500 mm wide
2. Stainless round bars: Ø 10–65/70-700 mm
3. Tool steel flat bars: 8–45/50-500 mm thick, 50–1000/50-1500 mm wide
4. Tool steel round bars: Ø 10–65/70-700 mm

Global Logistics

Fast delivery to Europe, Asia, the Middle East, and North America.

Bulk Supply & Competitive Pricing

Discounts for wholesalers, traders, and large stock orders.

Quality Assurance

Mill test certificates, hardness reports, and strict tolerance control.

Custom Processing

Cutting-to-length, precision grinding, and pre-machining available.

By sourcing from FCS Tool Steel, buyers secure not only the material but also a reliable long-term supply partner capable of supporting their growth in competitive markets.

8. Conclusion

Both stainless steel and tool steel flat and round bars have standard size ranges tailored to their unique properties and end-use requirements. Stainless steel bars dominate in corrosive environments and aesthetic applications, while tool steel bars excel in dies, molds, and cutting tools where performance under stress is essential.

For buyers, traders, and wholesalers, choosing a supplier with an extensive size range, guaranteed quality, and global shipping capability is key. FCS Tool Steel delivers exactly that—making it the ideal partner for bulk stainless and tool steel procurement.