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Reference Material

Useful Tools & References

Access helpful charts, material references, and technical information to support your project planning and decision-making.

If you need additional guidance, our team is always available to help.

Downloadable Resources

Hardness Conversion Chart

Hardness values are approximate and may vary depending on material composition and processing conditions.

This online guide reproduces the Brinell, Rockwell C and Shore conversion values and material ranges in Chicago Flame Hardening’s printable reference. Download the original printable hardness chart (PDF).

How to use the hardness conversion chart

Find the value in the column for your stated hardness scale and read across the same row. Treat the result as an approximate comparison, not a replacement for testing in the scale required by your drawing. Material composition, structure and processing affect hardness relationships. Confirm the material, test method and acceptance requirements before using a converted value for a production decision.

Hardness conversions from the CFH printable guide
Brinell Rockwell C Shore
682 62 84
653 60 81
627 59 79
601 58 77
578 56 75
555 55 73
534 54 71
514 52 70
495 51 68
477 50 66
461 48 65
444 47 63
429 46 61
415 44 59
401 43 58
388 42 56
375 40 54
363 39 52
352 38 51
341 37 50
331 36 48
321 34 47
311 33 46
302 32 45
293 31 43
285 30 42
277 29 41
269 28 40
262 27 39
255 25 38
248 24 37
241 23 36
235 22 35

Steel and iron reference ranges

These Rockwell C ranges are reproduced from our published chart. They are reference values, not guaranteed achievable hardness, material certification or a substitute for review of your specific part. The original chart does not identify the material condition or processing assumptions for each range.

Material reference ranges from the CFH printable guide
Steel / iron type Rockwell C range
1020 mild steel 30–35
1035 45–50
1040 50–55
1045 55–60
1060 60–65
1145 55–60
1545 (speed treat) 55–60
4140 58–62
4150 (maxel 3.5) 60–65
4340 55–60
52100 60–65
8620 40–45
Meehanite GA 55–60
Ductile Iron 35–65
Gray Iron 35–60
A36 40–45

Does this guide include Vickers hardness?

No. This company chart covers Brinell, Rockwell C and Shore. If your drawing specifies Vickers or another test method, send that requirement with your inquiry rather than substituting a scale from this chart.

What information should I include with a hardness requirement?

Send the material grade, drawing, hardness scale and range, surfaces to be treated, any case-depth requirement, inspection method, previous heat treatment and remaining machining allowance. Our team can review the requirements for flame hardening and related processing.

Request a project quote, email sales@cflame.com, or call (219) 397-6475.

Quick Reference

  • Maximum capacity: 100,000 lbs
  • Maximum length: 30+ ft
  • Materials: Carbon, Alloy, Cast Irons
  • Services: Flame Hardening, Stress Relieving, Straightening

Process Overview

🔥 What is Flame Hardening?
A surface hardening process that increases wear resistance by heating specific areas and rapidly quenching.

⚙️ What is Stress Relieving?
A controlled heating process used to reduce internal stresses and improve dimensional stability.

🔧 What is Mechanical Straightening?
A process used to correct distortion and restore dimensional accuracy in large components.

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