Wexmar provides custom plate and base plate machining for OEMs, automation builders and tool shops that need mounting plates, base plates, sub-plates, adapter plates, top plates and cover plates machined to print. Our Canastota, New York shop produces CNC machined plates on Mazak horizontal machining centers and finishes precision surfaces on an in-house surface grinder.
What plates do and who buys them
A machined plate is often the foundation of an assembly. Base plates carry motors, pumps, sensors and linear guides and set their alignment. Sub-plates and fixture plates provide a flat, repeatable surface for workholding. Mounting and adapter plates connect components with different bolt patterns. Cover and access plates seal openings. Because every component on a base plate references its surfaces and holes, flatness and hole position drive the accuracy of the whole machine. Buyers include automation and machine builders, pump and fluid power OEMs, instrumentation and optical equipment makers, fixture builders and defense build-to-print programs.
How we machine CNC plates and base plates
Plates are machined on our six Mazak horizontal machining centers: two FH4800s, a PFH4800, a Nexus 4000-II and two Nexus 5000-II machines with pallet changers and 4th-axis rotaries. We mount plates on tombstones or angle plates, which lets us machine the face and edges in one setup and keep edge datums square to the face. Hole patterns, counterbores, pockets, slots and tapped holes are located from those datums. Pallet changers keep the spindle cutting while the next plate is loaded. See horizontal CNC milling.
When flatness and parallelism are tighter than milling will hold, we finish plates on our surface grinder. Blanks are cut on our KASTO saws, and for flatness-critical aluminum work we often start with cast tooling plate such as MIC-6, which is stress-relieved and stable. Plate size is limited by our horizontal machine envelopes, so send the drawing and we will confirm fit. See our machine list.
Plate materials
- Aluminum: 6061-T6 rolled plate, MIC-6 and ATP-5 cast tooling plate, 7075 for strength.
- Steel: A36, 1018, 1045 and 4140 pre-hard for rigid bases.
- Stainless: 303, 304, 316 and 17-4 PH for washdown and cleanroom service.
- Others: tool steel for wear plates, brass and bronze, and engineered plastics such as acetal, UHMW and PEEK.
Critical plate features and how we hold them
- Flatness: controlled by stable material, flipping and re-clamping to balance stress, light finish passes, and surface grinding when required.
- Parallelism: both faces finished to a common reference, ground where tolerance calls for tenths.
- Hole true position: tapped, reamed and counterbored holes located from edge or dowel datums in one setup.
- Dowel holes: reamed for press or slip fit to set repeatable location of mounted components.
- Edge squareness: edges machined in the same setup as the face so they can serve as datums.
Typical tolerances and finishes
| Feature | Typical tolerance | Tighter on request |
|---|---|---|
| Face flatness (milled) | 0.002 in | 0.001 in |
| Face flatness (ground) | 0.0005 in | 0.0002 in |
| Parallelism | 0.002 in | 0.0003 in (ground) |
| Hole true position | 0.005 in | 0.001 in |
| Reamed dowel hole | +0.0005 / -0.000 in | +0.0002 / -0.000 in |
| Surface finish | 63 Ra milled | 16 Ra ground |
These are typical values that scale with plate size and thickness. Large, thin plates are the hardest to hold flat, and we will say so at quote stage if a callout needs discussion.
Secondary operations
Anodizing, chem film, powder coat, paint, black oxide, zinc and nickel plating, stress relief and heat treat are performed through qualified outside processors. Flame, plasma or laser cut blanks and welded base frames are sourced through qualified outside processors when a design calls for them, and we machine the critical surfaces after. Helical inserts and dowel pins are installed in-house.
Quantity patterns
Plates range from one-off base plates for a single machine to production lots of 25 to 500 mounting plates for OEM products. Tombstone fixturing and our second shift keep repeat plates economical.
Inspection
Hole positions and edge datums are measured on our Brown & Sharpe CMMs. Flatness and parallelism are checked on a granite surface plate with indicators and on the CMM. Threads are verified with go/no-go gages and reamed holes with pin gages. CMM reports, AS9102-format first articles and material certs are available. See inspection and quality.
Getting a quote
Send a drawing with plate size, material, flatness, hole callouts and quantity. You can upload a drawing for an instant estimate, and an estimator will confirm pricing. Or call (315) 400-2654. Related: brackets and fixtures and jigs.