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What machine surfaced this cast iron table?

steamandsteel

Aluminum
Joined
Oct 21, 2017
Location
Wichita, KS
Hello,

I've now got three tables with these similar "machining" marks on the surface. Third time's the charm, so here I am. WOC is about one inch, on all three. Linear, in a single direction. No visible tooth marks.

Too wide of a cut for a shaper, no circular cutting marks from a mill, don't THINK you'd get that surface finish from a surface grinder...

Additionally, what is this largest table that you see below? It has substantial webbing on the opposite side of the casting. All five sides appear to have been surfaced. Is it a surface plate for inspection/gaging? Just a table? Probably 600-800lbs, I found only a few markings.

Let's discuss. I'm very curious now, and I'm certain someone here can enlighten me

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Yup, planer. With a broad-nose finish tool. My dad had a workbench/layout table from Challenge Machinery Co. similar to what you show. Wish I had it, went to house clean-out guy.


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Hello,

I've now got three tables with these similar "machining" marks on the surface. Third time's the charm, so here I am. WOC is about one inch, on all three. Linear, in a single direction. No visible tooth marks.

Too wide of a cut for a shaper, no circular cutting marks from a mill, don't THINK you'd get that surface finish from a surface grinder...

Additionally, what is this largest table that you see below? It has substantial webbing on the opposite side of the casting. All five sides appear to have been surfaced. Is it a surface plate for inspection/gaging? Just a table? Probably 600-800lbs, I found only a few markings.

Let's discuss. I'm very curious now, and I'm certain someone here can enlighten me

View attachment 279345
View attachment 279346
View attachment 279347

Planer. Circa 1950-52 Alzmetall drill press table is similar.

Common as dirt long ago, less-so now.

Intentionally tooled to "show" it's own tattle-tale wear-pattern if/as/when and where worn unevenly as well as to reduce "wringing" or stiction when positioning work atop it that wanted moving about in fine increments without arguments.

Absent hand-scraping, it would be a "working" side of the shop layout and assembly alignment and fit-up aid.

Bitchin' grand "work bench" for some folks, some trades, but most 'ere would find it a chore to mount it properly and avoid damaging it.

"Inspection" plates WOULD be scraped to finer accuracy. Cast Iron, not granite, plates dominated up until they went seriously scarce, War Two priorities. That recent.

A monument-maker then resurrected the stone plates as used by the ancients. I have one. A genuine "Herman" brown granite in Grade A. Bigger monument makers such as "Rock of Ages" followed suit in pinks and salt & pepper grey-whites, others in black granite & gabro. Granites & c. came to dominate inspection and layout, even certain types of speciality "machine" tables.

Cast Iron still has its merits, but it is hard to compete on price with a billion or so years head start on stress relief of the materials that granite & such start OUR use of them with already "built-in"!

:D
 
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I agree with the other guys, definitely planed. We used to call it " Flat Tooling ". Maybe a 1" wide flat tool with a large feed stepover on each stroke. Most guys would put a 0.0015" feeler under one corner of the tool to create a very slight saw tooth effect with a sort of pin stripe look. . As Thermite mentioned it makes moving larger components around the table easier.

Regards Tyrone.
 
That table top looks like what they called a "stone" in printing shops back in the "hot metal" type days, and I bet that's where that thing originated.

Most every machined iron surface in our school print shop, and in the newspaper printing plant I worked at, had the exact same finish. Presses, paper cutters and tables.

Planed.
 
Hey Thermite, like I stated before about granite surface plates. We use them all throughout our working career. Then, when we go to "The Great Machine Shop in The Sky" our widows can make our tomb stones out of them!
 
So I saw this thread earlier today and I saw that pattern on the table, and I had
never ever seen that before. Interesting.

A few hours later I FINALLY cleaned off a cast table I had sitting around and gathering
dust for a dozen years. Threw a DA to it so I could use it as a welding table and what
do you know.

49559353136_c5c17eb1f1_c.jpg


Also related, I had the mating cast table until this morning. I loaded it onto
my truck and gave it away, with 3 working drill heads on it. It was originally
2 tables bolted together and total of 6 drills.

49558874113_26dd54630d_c.jpg


And YES, I *GAVE* it away. I had drilled maybe 2 holes with it in a dozen years,
and it was taking up room, and it was in too good of a condition to throw outside.

I gave it to a good customer of mine, a fab guy. Less than half mile down the road,
I'll probably see it at least 3 times a week for the next 10 years, and he'll get a
lot more use out of it than I ever did.
 
I agree with the other guys, definitely planed. We used to call it " Flat Tooling ". Maybe a 1" wide flat tool with a large feed stepover on each stroke. Most guys would put a 0.0015" feeler under one corner of the tool to create a very slight saw tooth effect with a sort of pin stripe look. . As Thermite mentioned it makes moving larger components around the table easier.

Regards Tyrone.

Fascinating, Tyrone. It makes sense, so every inch or so there’s a very slight ridge to keep pieces from sticking to the whole surface. Metal planers are new to me, but seems like they’re quite versatile! Glad this mystery has been solved.
 
Fascinating, Tyrone. It makes sense, so every inch or so there’s a very slight ridge to keep pieces from sticking to the whole surface. Metal planers are new to me, but seems like they’re quite versatile! Glad this mystery has been solved.

Compared with Plano-mills planers are much slower in production but on the other hand they are very forgiving of geometrical inaccuracies in the machine structure. Also a planed surface is also much easier to scrape than a milled or ground surface.

Regards Tyrone
 
Tyrone,

That's very interesting. Please elaborate.

There's not much to elaborate about. Both grinding and milling processes create a sort of " glazed " skin on the surface on the work. Planing doesn't do that so your scraper bites in nicely straight away instead of skidding across the cast iron. Once you get under the " glaze " everything is equal but that takes a little bit of effort.

Regards Tyrone.
 
There's not much to elaborate about. Both grinding and milling processes create a sort of " glazed " skin on the surface on the work. Planing doesn't do that so your scraper bites in nicely straight away instead of skidding across the cast iron. Once you get under the " glaze " everything is equal but that takes a little bit of effort.

Regards Tyrone.

I've learned something new! Thanks. Only 1,756,739 more facts and I'll know everything. :)
 
I've learned something new! Thanks. Only 1,756,739 more facts and I'll know everything. :)

Yah think? Might find at a high multiple of that 7/8ths of the world is convinced ye've gone stoopider, even MORE boring.... or both....

DAMHIKT!

:D

A.N Other reason is that a planed surface rats-out worn areas by the change to the pattern. Assessment can be faster and easier.

Annnnd it is not an easy pattern to cheat on and try to duplicate to hide that wear. As "cosmetic" partial re-scraping or flaking has "now and then" been found to be.

A ground surface may hide wear, and very effectively. Assessment can take longer.
 








 
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