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Herman Surface Plate Tool. What does it do Q?

machtool

Diamond
Joined
Jun 22, 2004
Location
Melbourne Australia
Gentelmen.

Completed auction. Herman Surface Plate Tool in Box | eBay

Mate of mine down here bought this, mostly because he forgot about a repeat-o-meter, the same seller had, so he bought this instead, on the rebound.

Only problem is, we have no idea what it does? I was thinking maybe a lap, but it has proud labels top and bottom.

Any word's of wisdom, greatly appreciated.

Regards Phil.
 
He bought it with no clue on what it does:nutter:

Auction says it comes with operating instructions, the pic is difficult to read but looks like it says "Tol-Check inspection instrument ...for rapid checking of surface plate tolerances"

I have no clue but Hermann Schmidt is still in business - ask them.
Hermann Schmidt Precision Tools - Hermann Schmidt
Paul
 
Looks like a kind of early or rough "Planekater" the instrument / gage used to calibrate a plate. Google it for a good explanation.

Regards,
Chris
 
He bought it with no clue on what it does:nutter:

Auction says it comes with operating instructions, the pic is difficult to read but looks like it says "Tol-Check inspection instrument ...for rapid checking of surface plate tolerances"

I have no clue but Hermann Schmidt is still in business - ask them.
Hermann Schmidt Precision Tools - Hermann Schmidt
Paul

I think it is made by Herman Stone who were an early manufacturer of granite surface plates rather than precision tool maker Hermann Schmidt. I can only think that it sits on the plate at one end as it does appear to have a small foot on one end with some type of measuring device at the other end. The large block might be moved from one end to the other while looking for movement at the measuring end. Just a thought

Mark
 
Unfortunately the pictures on ebay no longer appear. One of other threads mentions "Tol-Chek inspection instrument" which I will talk about below.

In fiscal 1970, Starrett bought Herman Stone Co., a Dayton, Ohio, producer of granite slabs for measuring tables, for $308,000 worth of stock. It was made a division of Starrett and moved to Mount Airy, North Carolina, in 1972. (BTW, I visited this quarry 20 years ago.)

I have a collection of Starrett Granite Surface Plates and Accessories catalog 807. Issue 3, 4, 5, 8, 9 and 12 from 2-1-75 to 11/94. The Tol-Chek last appeared in my issue #5 (4-1-78). Issue #8 was dated 9-15-82. So sometime between 1978 and 1982 Starrett discontinued manufacture of the Tol-Chek.

Here is what the catalog stated for Tol-Chek:

"Tol-Chek is supplied with a master surface plate, and its function is to determine quickly the tolerance accuracy of any working surface plate by comparing readings taken on its surface to those taken on the master. Tol-Chek parts are made of steel with protective coatings to prevent corrosion. The base has an instrument finish and rides on three tungsten carbide pads. The arm is 5/16" (7.9 mm) chrome plated steel and projects 9" (225 mm). Supplied with a MASTER PINK master surface plate 18" long x 12" wide x 4" thick (450 mm x 300 mm x 100mm) finished to an overall accuracy of .000050" (0.0012 mm), or .000020" (0.0005 mm) (specify), and with a Starrett Super Precision Dial Indicator No 25-109, 2-1/4" diameter, .00005" graduation, .015" range, 0-3-0 dial reading, with a No. 5 carbide contact point. Furnished with a surface plate cover and an attractive, protective case for the Tol-Chek."

It is interesting to note that just below the Tol-Chek on the same page in the catalog 807 is Starrett's "Repeat Reading Gage" which is essentially their version of Rahn's Repeat-o-meter. If my memory serves me correct, Rahn developed the repeat-o-meter in the late 1950's and it was finally adopted into the Federal Spec GGG-P-463c in 1973. In Europe they call their version of the repeat-o-meter a "variation gage". In June 2001 Rahn Granite Surface Plate Co sold their intellectual property to TruStone Technologies. By the way, ASME B89.3.7 (which I helped write) has superseded/replaced GGG-P-463c. To my knowledge there are no other manufacturer's of Repeat-o-meters or repeat reading gages in the U.S. other than Tru Stone (Rahn version) and Starrett.

Ed
 








 
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