Surface Roughness Testing - Comparison of models for measuring Ra, Rmax, Rt, Rz

[schnuer]

Hello,
My employer is prepared to spend about $8~10K on a surface roughness tester. Has anyone experience with the SJ-401 by Mitutoyo or the Model 440 (Multiple Parameter Unit) by Precision Devices? Any other recommendations for measuring Ra, Rmax, Rt, Rz?

Our specifications are fairly simple. Ra 1.6, 3.2, Rmax=40; Rmin=25, (microns). Some capability to address porosity, ie. Sk (skewness), would be nice but not absolutely necessary. A skidless model would be preferred.

Unit will get heavy use and should last for many years.

[CarolX]

Can anyone help with this question?

[silentrunning]

We have the Mitutoyo SJ-201 which is the hand held model (kind of an entry level tester) and have had very good luck with it. It is used in severl areas of the shop and is easy to use. I'm sure the SJ-401 will be as reliable and a lot more versitile. We have been very satisfied with our Mitutoya equipment so far.

Doug

[ScottK]

Hi Schnuer - welcome to the cove!

I use a Pocket Surf portable roughness gauge for measuring machined brass and stainless steel. We only use the Ra scale.
Here is the current model, ours is older: http://www.mahr.com/index.php?NodeID=2410

It's an old gauge, but it's held up to being used by many people, many times a day - all of our operators, set up guys, QC inspectors, and R&D people used it multiple times on a daily basis. We keep it on a stand in the QC office.
If you use it heavily expect to replace the probes fairly frequently as they will see the most abuse. We replace ours every 6 months.

[schnuer]

The proposal has gone through to purchase an SJ-401 alright from Mitutoyo. We already own a Crysta Apex CMM from this company so it was an easy decision after all.

Thanks all for the replies.