CGR Technologies, Inc. - Machining Group

CGR Technologies - Machining Group has been delivering quality to our customers for over 70 years. We are committed to providing precision components that meet or exceed our customers expectations on every job. We focus on one thing: manufacturing high precision parts and assemblies made to your specifications. And we do it better than everyone else. We keep our pricing competitive and have an impeccable reputation for honoring our commitments.


Thin Wall, Close Tolerance Machining

CGR - Machining Group specializes in close tolerance machining to 50 millionths of an inch (.0013mm) on customer-designed parts that require tightly controlled dimensional and geometric tolerances – such as flatness, perpendicularity, roundness, run-out, parallelism, etc. – when measured in the “Free State” (unrestrained). We are particularly good at parts with thin wall sections that need these tight free state requirements.

Difficult To Machine Materials

Stainless Steels (440C, 410, 416, 347, 316, 304, 17-4, 15-5, and 13-8, A286), Inconel, Invar™, AM355 and Kovar, Titanium, Molybdenum, OFHC Copper, Nickel 200, Monel, Alloy Steel, CPM10V, Tool Steel, Manganese Bronze & Brass, 6061 and 7075 Aluminum, Polymer Plastics, Powder Metals.

Hard Turning, Grinding, Lapping

Because these operations generally are near the end of the manufacturing process, lack of quality control could be costly in terms of money and time lost. CGR - Machining Group, unlike many of our competition who farm out their grinding to outside suppliers, does all of our own grinding, honing, and lapping in house. CGR - Machining Group does hard turning on applications when the process is more cost effective than traditional grinding.

Critical Surface Finish Applications

CGR - Machining Group has the knowledge, experience and equipment to produce micro finishes as fine as 2 micro inches with flatness to 2 helium light bands. We do super finishing of diameters, bores, shoulders and faces of parts that require demanding critical sealing and mating surfaces. We also do “Match Grinding” of metering components, such as high performance valves, spools and sleeves that require specific diametrical clearances.

Mating Rings

Materials: Nitralloy, 440C, M2, M50
Sizes: Up to Ø11”
Critical features:
Heat Treated, Nitrided and coated
Hard turned ID, OD, & o-ring grooves within 16 ra & +/-.001
Ground ID, OD, & o-ring grooves within 6ra & +/-.0002
Surface ground within .0002 parallel
Parallel & flat within .0002-.0005
Magnetic Particle Inspection

Differential Testing

Fluid: Kerosene
Minimum flow rate (151 cc/minute min. at 5 psid)
Maximum flow rate (454 cc/minute max at 30 psid)
Actuation pressure, Closing (30.0 to 33.0 psid)
Valve leakage (5 cc/minute max at 33 psid)
Actuation pressure, opening (27 psid min.)

Sealing Face Finish Lapping

Lapped flat within 2 HLB or 3 HLB
Parallel to opposite mating surfaces within .0002
Polished flat with 2 Ra or 4 Ra
Scratch free under 1X mag

Aluminum Castings

C355 T71 Aluminum Casting
Anodized & Dyed Red
Turned, Milled and Deburred
Fluorescent Penetrant Inspection
Chem Film

Complex, Tight Tolerance Parts

Material: Inconel 718, Dimensions: Ø0.57" x 2.4” Long, 0.075" Wide Face Groove at 30°, Several Ø+/-0.0005" Turned Features, 0.002" Max Break Weld Lip edges, Ø0.063" Thru Center Hole, 0.0005" Runout


Contact Us

CGR Technologies, Inc.
Machining Group
160 Bond Street
Elk Grove Village, IL 60007
E-Mail: sales@cgrtech.com
P: (847) 437-1717
CGR Technologies, Inc.
Stamping Group
346 W. Colfax Street
Palatine, IL 60067
Email: sales@cgrtech.com
P: (847) 934-7622