Surface Roughness
Surface Roughness
(OP)
Hi, does someone could help me, please?
An Automotive customer ask us for a mechanical part made by turning.
The surface roughness required is 4/Pt12.
Does anybody know what it means?
Thanks.
An Automotive customer ask us for a mechanical part made by turning.
The surface roughness required is 4/Pt12.
Does anybody know what it means?
Thanks.





RE: Surface Roughness
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RE: Surface Roughness
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RE: Surface Roughness
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Surface Roughness
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
Chinese prisoner wins Nobel Peace Prize
RE: Surface Roughness
I don't know the roughness standard they are using, but our customer is a german supplier of a big automotive brand.
On some surface of the piece they require Rz16.
RE: Surface Roughness
* in many cases based on German DIN standards
RE: Surface Roughness
http://en.wikipedia.org/wiki/Surface_finish
RE: Surface Roughness
You could take a look at ISO 1302, it has a conversion between current Ra values and obsolete Roughness Grade Numbers. The obsolete number system always starts with the letter "N". An N4 roughness grade number corresponds to 0.2 Ra (in microns). Still no mention of the /Pt12.
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Surface Roughness
* has been in print from 1954, and I believe still is
RE: Surface Roughness
We don't understand the mean of the number 4.
We checked the roughness of the samples and we found these values:
Ra=1.2 Pt=6.5 measured on 1.75mm lenght.
RE: Surface Roughness
ISO 1302 explains the system for indication of surface texture. The numeral 4 that appears before the Pt designation is called the transmission band (ISO 3274) and indicates the short-wave filter or long-wave filter. According to ISO 1302, there should be a hyphen either before or after the value in order to indicate if it is the short-wave filter or long-wave filter:
4- means short-wave
-4 means long-wave
The units are mm.
RE: Surface Roughness
you mean the cut-off value I think.
ISO 4288 recommend these cut-off values:
Ra cut-off
<0.02 -> 0.08
0.02 - 0.1 -> 0.25
0.1 - 0.2 -> 0.8
2-10 -> 2.5
10 -> 8
Value 4 means an expected Ra between 2 and 10.
In this case it will not be a critical value because this surface is
made by turning.
RE: Surface Roughness
I used the terminology from ISO 1302, Section 6.5. The cut-off values define the limits of the filters, either short-wave or long-wave.