Inspection Grade A Surface Plates

Filter by

Length

Width

Surface Plate Grade

Plate Shape

Rectangle with Two Ledges

Color

Black

Red

Height

Weight

Material

Specifications Met

DFARS Specialty Metals

Exempt

Export Control Classification Number (ECCN)

REACH

RoHS

Squareness Tolerance

33 Products

Surface Plates

Rectangular Plate

Rectangular Plate with Two Ledges

With flatness tolerances thinner than a strand of hair, these plates give you the flattest possible surface for accurate measurements. They’re typically used as a reference plane to inspect finished products and calibrate precision measuring tools, such as height gauges and dial indicators. Unlike metal plates, these granite plates won’t rust or interfere with nearby electronics. They also won’t warp when temperatures fluctuate. To maintain their flatness and finish, rotate plates regularly and apply granite cleaner (not included) to remove particles without leaving a residue.

Also Available: Other plate sizes. Please order 2245A999 and specify grade, length, width, thickness, and with or without ledges.

Inspection-Grade A Plate—Your go-to for general inspections and quality-control work. These plates are slightly less precise than grade AA plates with double the flatness tolerance.

Rectangular Plate with Two Ledges—Choose these plates if you need to mount fixtures and instruments with a clamp.

Black—Harder and denser than red plates to handle heavier loads, such as large bearings and other machined parts.

Red—Resist wear better than black plates to last up to five times longer. With a higher percentage of quartz, you can slide parts across these plates without worrying about nicks and scratches.

Surface Plate Covers—Prevent dust and debris from accumulating on plates when you’re not using them.

	Plates													Surface Plate Covers
								Rectangular Plate			Rectangular Plate with Two Ledges
	Flatness Tolerance	Lg.	Wd.	Ht.	Color	Specs. Met	Certificate Type	Wt., lb.		Each	Wt., lb.		Each		Each
Inspection-Grade A Plate







				Black Granite

				0.0001"	6"	4"	2"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	7	00000000	0000000	—	———	0	———	0


				0.0001"	12"	8"	2"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	28	0000000	000000	—	———	0	000000000	0000000
				0.0001"	18"	12"	4"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	93	0000000	000000	83	0000000	0000000	00000000	00000
				0.00015"	24"	18"	4"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	185	0000000	000000	175	0000000	000000	00000000	000000
				0.0002"	36"	24"	6"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	555	0000000	00000000	530	0000000	00000000	00000000	000000
				0.0004"	48"	36"	6"	Black	ASME B89.3.7, Fed. Spec. GGG-P-463, ISO 10012	Accuracy Certificate Traceable to NIST	1,110	0000000	00000000	1,063	0000000	00000000	00000000	000000




						Granite

						0.0001"	12"	8"	2"	Red	ASME B89.3.7, Fed. Spec. GGG-P-463	Accuracy Certificate Traceable to NIST	20	00000000	000000	—	———	0	000000000	000000

Surface Plate Stands

Rolling

Stationary

Attach to plates at three support points to keep them from sagging and warping, as specified in Fed. Spec. GGG-P-463-c. The welded steel construction offers greater strength, durability, and stability than economical alternatives such as block and wedge systems.

Rolling—Conduct measuring and inspecting tasks anywhere in your facility. With steel plate casters and hard, durable wheels, these stands support the same capacities as their stationary counterparts. Turn the adjustable screws on top of the stand to level the plate on uneven floors.

Stationary—Create a permanent setup for routine measurements and inspections. Twist the mounts at the bottom of each leg to level the plate, even on uneven floors.

	For Plate						For Rectangular Plates		For Rectangular Plates with Two Ledges
	Lg.	Wd.	Ht.	Load Cap., lb.	Ht.	Material		Each		Each
Rolling



		18"	12"	3", 4"	400	36"	Painted Steel	00000000	0000000	00000000	0000000


		24"	18"	3", 4"	500	36"	Painted Steel	00000000	000000	00000000	000000
		36"	24"	4", 6"	1,200	36"	Painted Steel	00000000	00000000	00000000	00000000
		48"	36"	6"	2,400	36"	Painted Steel	00000000	00000000	00000000	00000000


		Stationary



				18"	12"	3", 4"	400	36"	Painted Steel	00000000	000000	00000000	000000


				24"	18"	3", 4"	500	36"	Painted Steel	00000000	000000	00000000	000000
				36"	24"	4", 6"	1,200	36"	Painted Steel	00000000	000000	00000000	000000
				48"	36"	6"	2,400	36"	Painted Steel	00000000	000000	00000000	000000

Granite Inspection Setup Blocks

Image of Product. Front orientation. Inspection Setup Blocks.

Machined in pairs, these blocks are precision ground to tolerances thinner than a sheet of paper to give you the flattest and squarest surface for positioning workpieces. Since they are perfectly aligned to one another, they’ll keep your workpieces level and parallel. Also known as 1-2-3 blocks, they're typically used to elevate, support, and align parts for measuring and inspecting. They're made from granite, so they won’t scratch the surface of your workpiece. They also won’t warp when temperatures fluctuate. Unlike metal blocks, these granite blocks are nonmagnetic, so they won’t interfere with sensitive electronic equipment. They come with a certificate of accuracy that's traceable to NIST.

Inspection-Grade A Plate—Inspection-grade A blocks are your go-to for general inspections and quality-control work. These blocks are slightly less precise than grade AA blocks with double the tolerance.

				Tolerance
	Lg.	Wd.	Ht.	Lg.	Wd.	Ht.	Squareness	Parallel	Material	Certificate Type		Pair
Sold as Matched Pair







				Inspection-Grade A Plate

				1"	3"	2"	-0.0002" to 0.0002"	-0.0002" to 0.0002"	-0.0002" to 0.0002"	0.0001"	0.0001"	Black Granite	Accuracy Certificate Traceable to NIST	00000000	0000000