Surface roughness in uin or um in usa?

[Robin]

I am in Canada and we use both si and us system. I was reading in the
machinery handbook about surface roughness and they say that unit used (for
surface texture) should be consistent with the other unit used on the
drawing. I then suppose that surface texture should be us then something
between 16 and 128. However, all the examples are in si unit, showing
roughness like 1.6 and 3.2?

S
--
Robin
Mech eng

SW2001 SP14 &SW2001+ SP5.1
AMD 1333 512 ram
Spaceball
Hacked GeForce 3 to Quadroo what do us drawing use???

[Robin]

So what us drawing use?

"Robin" <robin_boudr...@hotmail.com> wrote in message
news:iQA%9.251550$C8.8...@nnrp1.uunet.ca...

[Dale Dunn]

With inch drawings, use microinches. Usually in the range 16 to 128. 1.6
and 3.2 are probably in micrometers, to be used with metric drawings.

--
Dale Dunn
Design Engineer
www.jamestool.com

[Doug Dorton]

Robin,

iso = us
6.3 = 250
3.2 = 125
1.6 = 63
0.8 = 32
0.4 = 16
0.2 = 8

Hope this helps
Doug

"Robin" <robin_boudr...@hotmail.com> wrote in message news:<zRA%9.251551$C8.8...@nnrp1.uunet.ca>...

[Tony O'Hara]

Whatever happened to N series

Roughness values Ra Roughness Grade Numbers
mm min
50 2000 N12
25 1000 N11
12.5 500 N10
6.3 250 N9
3.2 125 N8
1.6 63 N7
0.8 32 N6
0.4 16 N5
0.2 8 N4
0.1 4 N3
0.05 2 N2
0.025 1 N1

Courtesy 'Precision Devices, Inc'
http://www.predev.com/smg/specification.htm

--
Tony O'Hara
Melbourne, Australia

"Doug Dorton" <dbdo...@hotmail.com> wrote in message
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[Tony O'Hara]

Whoops, forgot not to use anything from HTML source

Roughness values Ra Roughness Grade Numbers
mm min
50 2000 N12
25 1000 N11
12.5 500 N10
6.3 250 N9
3.2 125 N8
1.6 63 N7
0.8 32 N6
0.4 16 N5
0.2 8 N4
0.1 4 N3
0.05 2 N2
0.025 1 N1
Courtesy 'Precision Devices, Inc'
http://www.predev.com/smg/specification.htm

--
Tony O'Hara
Melbourne, Australia

"Tony O'Hara" <ton...@cfcl.com.au> wrote in message
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