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Unregistered
09-15-2006, 12:00 PM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.

Robert Fogt
09-15-2006, 10:56 PM
I found a page with much information on this, its a good read.
http://www.mmsonline.com/articles/1102gage.html

It says, if the manufacturer uses Rz and the customer uses Ra then a ratio of 4 to 1 or 7 to 1 is ok. But if the manufacturer uses Ra and the customer uses Rz the ratio will be higher, up to 20 to 1.

Unregistered
05-23-2007, 04:54 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.
PLS convert 12.5Rz to Ra.

pungal
07-05-2007, 03:47 AM
pls. convert 12.5ra to rz,

pls.convert 6.3Ra to Rz

pungal
07-05-2007, 04:29 AM
pls.convert 6.3Ra to Rz,

pls.convert 12.5Ra to Rz

Robert Fogt
07-06-2007, 09:37 PM
There is no direct conversion. Try following this link:

I found a page with much information on this, its a good read.
http://www.mmsonline.com/articles/1102gage.html

It says, if the manufacturer uses Rz and the customer uses Ra then a ratio of 4 to 1 or 7 to 1 is ok. But if the manufacturer uses Ra and the customer uses Rz the ratio will be higher, up to 20 to 1.

Unregistered
08-17-2007, 10:40 PM
need Rz 60 in Ra

Unregistered
08-17-2007, 10:47 PM
I need to convert an Rz10 surface spec to Ra. Please and thanks in advance

ABHIJIT DUTTA
11-06-2007, 03:41 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.
Rz 2.5 = ? Ra

Unregistered
01-08-2008, 12:39 PM
Assuming Rz DIN verses Rz ISO
Conversion factor = 7.2

Ra = Print Rz / 7.2

If print is in metric micrometer and you want english microinch equivalent
then ...

Ra = (Print Rz / 7.2) x 40

example: Print states 6.3
Ra = 6.3 Rz / 7.2 = .87 Ra micrometer
or
Ra = (6.3/7.2) x 40 = 35 Ra microinch

Popular conversion factors:

Rz Din = 7.2
Rz ISO = 7.6
Rmax = 8.0
RMS = 1.1

Kuei
04-30-2008, 06:39 PM
It might make the metric to english conversion a little less confusion if you show him where "40" comes from. If you show the mechanics behind your value he has a better chance of catching on.

40 is just a rough value from metric to english conversion.

Let's first look at the wording of the formula:
micro "meters" to micro "inches".

We all probably know that to convert millimeters to inches you divide millimeter values by 25.4. Ie.. 1mm = 1/25.4in or .03937.
And to go from inches to millimeters you go .03937x25.4 = 1mm.

You see how that .03937 looks alot like .04? Yup, .04 is just rounded just like 40 is rounded from 39.37. See where I'm going yet?

Now since the wording I pointed out in the beginning is "micrometers" and "microinches" you may see why our conversion is .03937 instead of 39.37.

The difference is micromillimeters and micrometers.
1 meter is 1000 millimeters.
The surface formula calculates micrometers to microinches, not micromillimeters to micro inches.

So to convert 3 micrometers to microinches here is what we do:
convert micrometers to micromillimeters. 3 micrometers = 3000 micromillimeters. 3 x 1000 = 3000.
next convert 3000 micromillimeters to microinches. 3000/25.4 = 118.11 microinches.

Using the correct formula instead of an abreviated formula or rounded number is much better. It's kinda like when machinists try to calculate sfpm using the value 3.82. Most never remember the formula because most don't know where 3.82 comes from. They don't understand the mechanics. So they can never do the math.

Unregistered
09-12-2008, 03:16 AM
Can we take Rz factor as 7.6 becoz it is for RZ ISO , TO CONVERT INTO Ra

SATHISH81
03-02-2009, 01:15 AM
[QUOTE=pungal]pls. convert 1.6ra to rz,

Unregistered
03-03-2009, 12:47 AM
It depends on a method of surface finicing, milling, drilling, eroding or lathing Rz is the heigt of the tallest "bump" on surface Ra is the avarage heigt of all the bumps on surface. And as we all know there is no direct link between avarage and max. Allthoug if u know the method u can derive something from it using a sample of surface finicing.

Unregistered
07-01-2009, 03:44 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.
rz 12.5 to 25 con to ra

Unregistered
07-01-2009, 03:49 AM
ra 125 con. to rpm & tooling feed

hpatel
07-03-2009, 09:34 PM
convert surface finish rz (12.5 to 25 ) to ra value

Unregistered
07-08-2009, 07:25 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.

I need to convert Rz1 to Ra

Unregistered
07-13-2009, 10:39 AM
What does ra stand for

Unregistered
07-24-2009, 08:24 PM
pls.convert Rz16 to Ra[/QUOTE]
I need to convert an Rz16 surface spec to Ra. Please and thanks in advance.

bgengg
07-26-2009, 03:58 AM
Rz value is 6.3. It should be converted into Ra

Unregistered
07-28-2009, 01:32 PM
I need to convrt RZ 39 to RA or a surface finish I can understand. HELP.

Unregistered
08-13-2009, 12:01 AM
i want to convert surface finish values Rz to Ra I need to convert an Rz surface spec to Ra. Please and thanks in advance.

Unregistered
08-17-2009, 05:54 AM
Rz100 to Ra

Unregistered
09-28-2009, 11:04 PM
[I need to covert 63 Rz to Ra

Unregistered
10-22-2009, 10:00 PM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.[/QUOTE]

Unregistered
12-16-2009, 02:23 AM
Pls convert surface fininsh 2.5 rmax to Ra

dhanushetty
01-20-2010, 05:04 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.please send us to conversion chart for Rz to Ra

Sameer
02-11-2010, 12:43 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.

I want to convert RZ=23 to Ra value

Unregistered
04-12-2010, 04:10 AM
[QUOTE=Unregistered;5946]I need to convert an Rz surface spec to Ra.

Unregistered
05-04-2010, 06:35 AM
I want to convert RZ=0.6 to Ra

Unregistered
11-30-2010, 02:51 AM
Rz 2.5 = ? Ra
convert surface finish - Rz to Ra

Unregistered
12-26-2010, 09:17 PM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.

I need to convert an 6.3 Rz surface spec to Ra

Unregistered
06-29-2011, 12:49 PM
PLS convert 12.5Rz to Ra.

please convert rz25 to a RA number

JCROOK
07-01-2011, 11:20 AM
There is no direct conversion!!!!

Ra is the arithmetic average of the peaks and valleys over the entire sample surface.

Rz is the average distance between the highest peak and lowest valley in each sampling.

rushil
09-06-2011, 02:26 AM
conversion factor?

Amart
10-22-2011, 04:18 AM
I want to convert Rmax 12 to Ry value.

ANAND SWARUP
11-16-2011, 01:34 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.
I need conversion chart which can convert surface roughness values specified in Rz to Ra. Thanks.

girde_ravi@rediffmail.com
11-28-2011, 03:25 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.

Unregistered
11-29-2011, 02:01 AM
pls.convert Rz10 to Ra,

Ikbal
12-15-2011, 08:10 AM
can you help me have a chart as to what surface finish can be achieved in which operation. Pl also provide a con ersion factor of Rz to Ra

Unregistered
01-25-2012, 01:31 AM
PLS convert 12.5Rz to Ra.[/QUOTE]

Unregistered
03-24-2012, 02:32 AM
I need to convert an Rzdin surface spec to Ra max. Please and thanks in advance.

Unregistered
04-15-2012, 04:08 AM

Unregistered
04-27-2012, 01:30 AM
pls.convert Rz16 to Ra
I need to convert an Rz16 surface spec to Ra. Please and thanks in advance.[/QUOTE]

Unregistered
08-06-2012, 06:42 AM
I need to convert an Rz 10 surface spec to Ra. Thanks in advance.

Unregistered
08-21-2012, 03:38 AM
Rz63 is equal to how much Ra

Unregistered
08-26-2012, 10:54 PM
pls.convert Rz16 to Ra
I need to convert an Rz16 surface spec to Ra. Please and thanks in advance.[/QUOTE]

Unregistered
10-15-2012, 12:36 AM
I need to convert an Rz10 surface spec to Ra. Please and thanks in advance

Unregistered
06-18-2013, 03:04 AM
I need to convert an Rz surface spec to Ra. Please and thanks in advance.
I need to convert an Rz surface spec to Ra. Please and thanks in advance

Unregistered
06-22-2013, 01:09 AM
pls.convert Rz16 to Ra
I need to convert an Rz16 surface spec to Ra. Please and thanks in advance.[/QUOTE]

Unregistered
07-18-2013, 07:59 AM
I need to convert a surface finish of a metal diaphragm with an Rz=1micrometer to Ra

s yuvaraj
09-12-2013, 01:47 AM
Ra to Rz conversion is simple method

Rz = 5 (Ra)

Unregistered
09-12-2013, 04:14 AM
please convert the Rz 6.3 to Ra