Explain the significance of surface plates in today’s manufacturing industry. Explain some modern uses of surface plates, and their significance in the high tech industry. Explain how surface plates...

Explain the significance of surface plates in today‟s manufacturing industry.
A surface plate is a solid, flat plate used as the main horizontal reference plane for precision inspection, marking
out (layout), and tooling setup. The surface plate is often used as the baseline for all measurements to a workpiece,
therefore one primary surface is finished extremely flat with accuracy up to 0.00001 in or 250 nm for a grade AA or
AAA plate. Surface plates are a very common tool in the manufacturing industry and are often permanently attached
to robotic-type inspection devices such as a coordinate-measuring machine. Plates are typically square or
ectangular. One cu
ent British Standard includes specifications for plates from 160 mm × 100 mm to 2500 mm ×
1600 m
Explain some modern uses of surface plates, and their significance in the high tech
industry.
Explain how surface plates are manufactured and certified.
The making of a surface plate using Whitworth-three plate method.
Whitworth's method involves using the plates of the same size and shape. The only way for this method to work is
using square or circle plates of same size and shape. The reason for this is because of twist especially if it is made of
cast iron.
You have to think of an unfinished flat surface as an uneven hilly yard. There are dips, valleys, and holes. You make
the yard flat by taking a shovel and removing the high spots until it is all flattened out. You might even fill in the dips
and holes while you are at it too.
Hand scraping a surface plate kind of works the same way but instead of filling anything in, you are only removing
the high points found using the blue dye after the surface plates have been ru
ed and rotated together with the blue
dye on it.
Whitworth-three plate method involves using three unfinished surface plates that are the same size and shape. Let's
call these surface plates A, B, and C.
You start with surface plate A and surface plate B make sure that all sides have no bu
s on them and that it is clean.
You can even use your hand to feel for anything and if so clean it off and debu
it before proceeding. Take surface
plate B or A but only one of them and use blue dye with a dye spotting tool and rub the plate down with it until its
completely and nicely coated on the unfinished surface of that plate. Take the other uncoated plate and make sure
there is no bu
s or dirt, then put the uncoated surface plate on to the coated blue dye surface plate make sure to only
softly put it on the coated plate. Rub the two plates together a couple of times to ensure the coated surface plate
makes contact with the uncoated surface plate and highlights the high points of the uncoated surface plate. softly and
slowly take off the surface plate with the high points highlighted with blue dye. Use a hand scraper and scrape the
high points highlighted with blue dye. Repeat the process until the scraped surface plate has a uniformed surface
highlighted with blue dye.
Now surface plate A matches surface plate B.
Do this same process with surface plate B and surface plate C.
Then do the same process with surface plate A and C.
Then you will have three surface plates of the same accuracy and flatness.
https:
en.wikipedia.org/wiki/Flatness_(manufacturing)
https:
en.wiktionary.org/wiki/plate
https:
en.wikipedia.org/wiki/Datum_references
https:
en.wikipedia.org/wiki/Marking_out
https:
en.wikipedia.org/wiki/Marking_out
https:
en.wikipedia.org/wiki/Coordinate-measuring_machine
https:
en.wikipedia.org/wiki/Debu
ing

Explain in detail, the differences between the commonly used granite surface plate, and
the “conventional” cast iron surface plate.
Granite
Before the Second World War, metal was the standard material used for surface plates, however, the war efforts of
various countries put a strain on the availability of metal. A monument and metal shop owner (Wallace Herman) in
Dayton, Ohio, along with his inventive employee Donald V. Porter, started using granite in place of metal for his
surface plates. Today most surface plates continue to be made of black granite, more accurately refe
ed to as black
diabase, with the more wear-resistant surface plates being made of quartz-bearing granite. The quartz content of
these granite surface plates increases the wear resistance of the plate as quartz is a harder stone. Black granite is
dominantly used in machine bases, granite accessories, and custom applications for its superior stiffness, excellent
vi
ation dampening, and improved machinability. Quartz-bearing granite (usually pink, white, or grey) is often
made thicker than black granite to provide equal load-bearing capabilities of the types of material used for surface
plates as it is not as stiff as black granite.
Damage to a granite surface plate will usually result in a chip but does not affect the accuracy of the overall plane.
Even though chipped, another flat surface can still make contact with the undamaged portion of a chipped surface
plate whereas damage to a cast-iron plate often raises the su
ounding material above the working plane causing
inspected objects to no longer sit parallel to the surface plate.
Granite is also inherently stable, non-magnetic, has excellent vi
ation damping characteristics, and will not rust.
On 3 August 1961, Federal Specification GGG-P-463B was issued to provide requirements in United States
customary units for igneous rock (granite) surface plates for use in precision locating layout, and inspection work. It
encompassed new certification, recertification in the field, and recertification after resurfacing. GGG-P-463B was
later revised and reissued on 12 September 1973 as GGG-P-463C, which provided common language and terms of
classification for surface plate manufacturing and commerce. On 15 June 1977 an amendment was issued to the
federal specification in order to include requirements in metric units.
Although GGG-P-463C was used extensively in American industry since its publication, the government did not
issue any new revisions to keep up with advancements within industry. The American Society of Mechanical
Engineers (ASME) decided to form a committee to revise the federal specification in accordance with modern
technologies. Most notably, a more complete glossary was added with cu
ently accepted definitions, and a new
format was used that should be more familiar to cu
ent users of the Standard. ASME also recognized the need for
updates to incorporate modern concepts such as traceability and measurement uncertainty that have undergone
considerable development since 1973. In June 2013, ASME replaced Fed Spec GGG-P-463C with the American
National Standard (ANS) ASME B89.3.7 – 2013 Granite Surface Plates.[5] Iso standard defines ISO8512-2 for
granite surface plates, but it seems the cu
ent in use is still dating back 1990.
Cast iron
Prior to World War II, almost all surface plates were made from ri
ed cast iron with the ri
ing used to increase
stiffness without incu
ing the weight of solid construction. The cast iron was aged to reduce stress in the metal in an
effort to decrease the likelihood of the plate twisting or warping over time.
Cast-iron surface plates are now frequently used on production floors as a tool for lapping granite surface plates to
achieve certain grades of accuracy. The metal allows itself to be impregnated with the lapping media over a large flat
surface.
Despite a fall in popularity among machine shops, cast iron remains the most popular material for surface masters
(different usage from a surface plate) among laboratory metrologists, machine builders, gauge makers, and other
high-accuracy industries that have a requirement for gauging flatness. Cast iron that has been properly cast is more
dimensionally and geometrically stable over time than granite or ceramics,[citation needed] is more easily worked to
a higher grade of flatness, and provides a better...