Rockwell Hardness Callout 1

[artnmotion]

What is the proper format for calling out a "Rockwell Hardness" on a drawing.

I've seen this on our prints:

Rc 60

 

[drawoh]

artnmotion,

You want a hardened part. You are specifying how hard a part you will accept. The Rockwell hardness should be part of your material specification, or part of your finish specification.

Material
CARBON STEEL AISI 1060 

Finish
HARDEN TO RC60

Material
CARBON STEEL AISI 1060 HARDENED TO RC60

Of course, hardening is not absolutely simple. Is this thing to be case hardened, or hardened through? It helps if your material can be hardened to Rc60.

--
JHG

 

[CheckerHater]

When it comes to format, I've seen Rc, RC, HRC, ROCK "C" and full text note as well.

I am not sure if there is dedicated drafting standard for that.


"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[KENAT]

If there is a relevant hardness testing spec or similar it may be specified in there e.g ASTM E18 or something.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Gilmiril]

ASTM E18-15, Standard Test Methods for Rockwell Hardness of Metallic Materials, contains the following:

5.2.2 The Rockwell hardness number is an arbitrary number, which, by method of calculation, results in a higher number for harder material.
5.2.3 Rockwell hardness values shall not be designated by a number alone because it is necessary to indicate which indenter and forces have been employed in making the test (see Tables 1 and 2). Rockwell hardness numbers shall be quoted with a scale symbol representing the indenter and forces used. The hardness number is followed by the symbol HR and the scale designation. When a ball indenter is used, the scale designation is followed by the letter “W” to indicate the use of a tungsten carbide ball or the letter “S” to indicate the use of a steel ball (see 5.1.2.1).
5.2.3.1 Examples:
64 HRC = Rockwell hardness number of 64 on Rockwell C scale
81 HR30N = Rockwell superficial hardness number of 81 on the Rockwell 30N scale
72 HRBW = Rockwell hardness number of 72 on the Rockwell B scale using a tungsten carbide ball indenter