304 Stainless Steel Round Disc Blanks — CNC-Turned Precision for Fabricators and DIYers
When a project calls for a flat, round metal blank that holds tight tolerances and resists corrosion without extra surface prep, finding the right stock can slow everything down. These 304 stainless steel round disc blanks are CNC-turned to consistent dimensions, giving fabricators, machinists, and hands-on builders a reliable starting point for custom parts, fixtures, and structural components.
Each disc is machined from 304-grade stainless steel — an austenitic alloy known for its balanced chromium-nickel content, smooth surface finish, and resistance to oxidation in most indoor and outdoor environments. Thickness options run from 10 mm (~0.39 in) to 60 mm (~2.36 in); outer diameters span 20 mm (~0.79 in) to 200 mm (~7.87 in). Quantity options range from 1 to 10 pieces per order, letting you match the purchase to the job.
Typical applications include custom shaft flanges and bearing seats in light machinery, spacer plates and standoffs in structural steel assemblies, base plates for welded brackets and mounting hardware, and blanks for further CNC milling, drilling, or laser engraving in prototyping workflows.
🔧 Compatible with standard milling, drilling, turning, and welding operations. Suitable for use with common stainless-compatible cutting fluids and tooling.
✅ Key Features of These 304 Stainless Steel Round Disc Blanks
⚙️CNC-Turned FacesEach disc is machined on a CNC lathe for flat, parallel faces and consistent outer diameter — reducing setup time when used as a blank for secondary operations.
🛡️304-Grade Corrosion ResistanceThe 18% chromium / 8% nickel composition of 304 stainless forms a passive oxide layer that resists rust in humid, wet, and mildly acidic environments without additional coating.
📐Wide Size MatrixThickness from 10–60 mm and OD from 20–200 mm cover a broad range of part requirements, from small precision inserts to large structural base plates.
🔩Weld-Ready SurfaceThe turned surface is free of mill scale, making it suitable for direct TIG or MIG welding without grinding prep in most applications.
📦Flexible Quantity OptionsOrder 1, 2, 3, 4, 5, or 10 pieces per variant to match prototype runs, small-batch production, or replacement part needs without over-ordering.
🔬Non-Magnetic Austenitic Structure304 stainless is non-magnetic in the annealed state, making these discs suitable for applications where magnetic interference must be avoided.
📐 Technical Specifications — Stainless Steel Round Disc Blank
| Material Grade |
304 Stainless Steel (UNS S30400) |
| Composition |
~18% Cr, ~8% Ni, balance Fe |
| Thickness Range |
10 mm – 60 mm (0.39 in – 2.36 in) |
| Outer Diameter Range |
20 mm – 200 mm (0.79 in – 7.87 in) |
| Shape |
Round / Circular Disc |
| Manufacturing Method |
CNC Turned |
| Surface Condition |
Turned (mill-scale free) |
| Finish |
See variant options |
| Quantity per Order |
1 / 2 / 3 / 4 / 5 / 10 pcs |
| Weight (per piece) |
See variant options |
| Tensile Strength (typical) |
~515 MPa (74,700 psi) |
| Yield Strength (typical) |
~205 MPa (29,700 psi) |
| Hardness (typical) |
~92 HRB |
| Magnetic |
Non-magnetic (annealed) |
| Weldability |
Good — TIG / MIG compatible |
| Inner Diameter / Bore |
Solid blank (no bore); Contact us to confirm custom bore options |
❓ Frequently Asked Questions
How do I choose the right thickness and diameter for my project?
Start with the load-bearing or clearance requirements of your application. Thickness determines the axial depth of the part — for spacers and standoffs, match thickness to the gap you need to fill. Outer diameter should be selected based on the bolt circle, bore size, or mating surface of the assembly. If you are using the disc as a blank for further machining, add at least 1–2 mm of stock on the OD to allow for finishing cuts.
Is 304 stainless steel strong enough for structural applications?
304 stainless has a typical tensile strength of approximately 515 MPa and yield strength of approximately 205 MPa, which is adequate for many light-to-medium structural uses such as brackets, flanges, and mounting plates. For high-stress or high-temperature structural applications, consider 316 or 17-4 PH grades. If you are unsure, consult a structural engineer for your specific load case.
Will these discs rust or corrode outdoors?
304 stainless steel resists rust in most outdoor environments due to its passive chromium oxide layer. However, in coastal or high-chloride environments (salt spray, de-icing salts), surface staining or pitting can occur over time. For marine or chloride-heavy environments, 316 stainless is a more appropriate choice. Periodic cleaning with a mild detergent helps maintain the passive layer.
Can I weld these discs to mild steel or other stainless parts?
Yes. 304 stainless can be TIG or MIG welded to itself and to mild steel using appropriate filler metals (e.g., ER308L for stainless-to-stainless, or ER309L for stainless-to-mild-steel dissimilar joints). The turned surface is free of mill scale, so no grinding prep is required in most cases. Post-weld passivation is recommended to restore corrosion resistance in the heat-affected zone.
Are these discs suitable for food-contact or medical applications?
304 stainless steel is widely used in food processing equipment and is generally considered food-safe when properly finished and cleaned. However, these discs are supplied as machined blanks and have not been certified or tested for specific food-contact or medical-device standards (e.g., FDA, ISO 13485). If your application requires certified material or specific surface finish standards, please contact us to confirm before ordering.
What secondary operations can I perform on these blanks?
These CNC-turned discs are suitable for a wide range of secondary operations including drilling, tapping, milling, boring, grinding, laser engraving, and further turning. The turned surface provides a consistent datum for fixturing. Use carbide tooling and stainless-compatible cutting fluid for best results. Avoid work-hardening by maintaining consistent feed rates and avoiding rubbing cuts.
How do I select the right quantity option?
Quantity options (1, 2, 3, 4, 5, or 10 pieces) are available for most size combinations. For prototyping or one-off repairs, a single piece is sufficient. For small-batch production runs or assemblies requiring matched sets, ordering 5 or 10 pieces typically reduces per-unit cost. Check the variant price displayed for each quantity to compare the per-piece rate before adding to cart.
🛒 Select your Thickness, Diameter, and Amount above, then add to cart.
