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Mitsui Surface Grinders

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Evaluating manual surface grinders. How does the quality of Mitsui Surface Grinders compare to other available brands?
 
I only have one data point. My Mitsui 6x18 (MSG-205MH) is a nice machine, despite years in the previous owner's shop mostly cutting off mold ejector pins. An instance in like-new condition would be very fine indeed. Most maintenance parts are readily available in the US.

I like the ergonomics of the Mitsui design. The height adjust micrometer dial is down where 5'6" operator (me) can get at it and read it easily, instead of being mounted near the top of the column. X travel on roller bearings is truly finger-tip (or gravity if not leveled) sensitive. X travel lock is solid and fast/easy to use.

The lubrication system is total loss, and drains neatly into a large sump in the rear of the base. If you don't drain that stuff out before moving the machine after years of operation, it will slop aaaaallll over. DAMHIKT.
 
I've used several on the job at various shops over the years. I didn't want to like the first one I used, being a resentful machine tool maker from America and all...., but I had to admit that it was a good grinder. Several places I worked had Mitsui's and Okamoto's that I used all day long. I've come to prefer them over the Boyar-Schultz and the lower end Harig's. Solid table/saddle stops/locks, smooth movement in all axis, balls/ways are replaceable, downfeed handle where I prefer it. I even bought one for my home shop. Beats any manual SG I've used except maybe a nice Parker Majestic (haven't used one).
 
My 2 cents
We have 5 of them here, all with the .00005 per graduation fine feed attachments on Y and Z. Love'em. In even half way decent condition they are the nicest and easiest manual surface grinders I've ever used.
 
I can't really add anything to what others have said, other than I've had one for years that came out of a big tool shop, and it's been trouble free. I love it, especially the positioning of the down feed hand wheel. Pay attention to the comment about the way oil sump... he's not the only one who found out the hard way.

Dennis
 
I have run and serviced the Mitsui 612 manual grinders. Very well made and accurate. Like better than any US made equivalent. Being a ball type roller way grinder, table must be removed to transport.
 
40+ years as a tool and diemaker and I have probably used every brand of surface grinders out there. Mitsui is by far, the best grinder I have ever used.
 
Mitsui smaller machine are very good. If I designed this machine I would have added a felt seal at the gap between the long travel and the saddle... agree many/most grinders have this problem with grinding grits bouncing off the column and getting into the balls/rollers area.
As I have mentioned I use a strip of masking tape to cover that opening on new machine or after a cleaning..

Mitsuis are so easy to pull the long travel top I think that should be done every two years for a cleaning.

Personally I like a scraped iron oil bed ways the best but it is getting harder to find such except for having an older machine re scraped.
Another thing about ball and roller machines is that a very free running long travel tends to pull the table forward at the start of a climb grinding pass so causing more heat on thet side of the part..

Agree the Mitusi with a tight long travel feed strap one can control the lead-in on the climb side.
 








 
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