Your cart is empty.
Your cart is empty.HHIP 12 X 9 X 2" Granite Surface Plate Grade B 0 Ledge The top surface of this plate is precision ground to achieve a high degree of flatness and the accuracy is +/-.0001". It is a Grade B (Grade 1) plate. Granite surface plates meet or exceed Federal Specifications GGG-P-463C and it includes a certificate of inspection. (Note that these are not NIST traceable.) Granite plates are used for measuring the flatness and squareness of other objects, laying out parts, calibrating instruments, setting up tools, checking parallelism and perpendicularity, and measuring heights with the use of a height gage. They are also used as a work surface for assembling, inspecting, and marking parts. Non-magnetic and non-conductive. Surface plates are offered by HHIP in various sizes, with different levels of flatness and accuracy and are checked by an auto collimator for overall accuracy assurance.
Robert
Reviewed in the United States on March 3, 2025
My set up has a base of solid 3/4" thick steel milled to .001" , then a 1/8" corrugated cardboard sheet with the A grade granite sitting on top of it. My test system is a ultra-precision block 3x4x1" accurate to .000003" in all directions with a Starrett surface gauge corrected and machined to same tolerance bolted to it. A Brown and Sharp .00005" indicator is attached to the set up. This unit can detect .000005" inch variations and easily measure accurately to .0001". The results were conclusive that there was less than 50 millionth inch variation and probably consistently measured within 10 millionth in the center.... With minor touch ups it is near perfect for me. Great piece
Tachsman
Reviewed in the United States on March 1, 2025
Came well packaged in a wooden crate that was boxed and with no damage to the slab. Using a 0.0005" gauge over the entire surface, I saw no deflection of the needle. Therefore, my granite slab appears to be at or near the stated flatness of 0.00005" Class A-0 as advertised. I am very pleased as it is what my home workshop needed for precise metal working.
Dan M
Reviewed in the United States on August 11, 2024
Passes my inspection. The surface indeed appears to be at least close to the stated flatness, according to my testing with a .0005" indicator, which can only measure about +/- .0001 reliably.Be aware that the sides are not square with each other, or square with the face. Not even close. So if you need a square, consider a higher end plate that would probably also be precision ground square on 5 sides. This is not advertised as a square though, just a flat surface, and that's what I received.
Steven K. Seawell
Reviewed in the United States on June 22, 2024
Nice grade of granite slab for my primary home use of block sanding and refurbishing small machined part surfaces with fine sandpaper. My slab appears to be very flat, checking it with a precision ground machinist`s parallel bar. I wiped off the slab with a water based cleaner and waxed the top surface and sides with Meguire`s cleaner car wax. The bottom of the slab is, as expected, rough cut and mine sits flat.Good value for the price.
Robert
Reviewed in Canada on December 28, 2024
Perfectly flat and smooth
Disappointed Customer
Reviewed in the United States on November 8, 2024
So I ordered two of these, one "A" one "B", both 12" x 18". While it is impressive to get a mostly flat 80lb piece of granite delivered to my door for a little over $100, they are not nearly as flat as they claim. Despite the Chinese certificate of accuracy (very reassuring) both plates had a noticeable dip in the middle when putting a Starrett straight edge across them. A .0015" feeler gauge would quite fit under the straight edge, and I estimated the error in flatness to be about .001" by taking carful measurements with a machinist's level. They are concave in both axes, but it is more pronounced along the 18" length.All and all they are good for the money and I plan on keeping both and experimenting with lapping them. Just know that if you are expecting high accuracy flatness better than .001" you will be disappointed. If you want an affordable lapping project, then these are a good choice.
DA
Reviewed in the United States on October 14, 2024
This product arrived fast and was package in a wooden crate for protection. It arrived in perfect condition.The top and bottom is smooth and top beveled. This will be perfect for leather stamping and setting riviets.I am very pleased with this purchase
A M Fytche
Reviewed in the United Kingdom on January 17, 2024
GREAT QUALITY AND VALUE FOR MONEY.
jorge beltran sanchez
Reviewed in Mexico on February 4, 2023
Para algunas medidas bien
Kai-Ara Lhasa Apso Kennels
Reviewed in the United States on December 20, 2023
As the title says, this was a fabulous purchase and is perfect for my leather work. The photo doesn't show it's thickness as I've countersunk it with just a small amount raised above the desk surface. I will start by saying it's HEAVY. I don't think I realized just how heavy this would be and even lowering it into the cutout compartment area was a huge feat. I will advise that if you intend to do leather stamp work on this it will require something to absorb the shock underneath. Mine is resting on a foam yoga mat like surface in a build in/converted keyboard tray slide out which we reinforced. This photo shows it with the dusty look it had upon receipt but after one quick cleaning it has not had that look any longer. It's very nicely smoothed. The edges are nice, there are no imperfections and this was just a fabulous purchase! Highly recommended.
Mouse cat
Reviewed in the United States on September 12, 2022
It is delivered with a solid wooden box to secure and protect the stone, very good, the stone size is accurate.One star to be deducted, I bought two as a desktop speaker foundation, the color is the same but the pattern is totally different.
kcwcc
Reviewed in Canada on March 1, 2022
Always wanted one, couldn't justify it. When the requirement came up I figured I had nothing to lose and I am pleasantly surprised. Very well packaged and very flat. I ran my .0001" dial on it and it's flat enough for my purposes. The "Ladoratory" Superviser on the included cut sheet agrees :)
Customer
Reviewed in Canada on December 12, 2020
Have yet to test the accuracy, but from first impressions the quality is very good. The product arrived very fast and ahead of schedule. It came with a calibration certificate similar to the sample. Very impressed, for a hobbyist I don't think you can beat the price for the quality.
Recommended Products
$349.99
$ 99 .00 $99.00