Brass Machined Washers — CNC Turned Precision Brass Washers

While stamped washers cover standard metric and imperial sizes, many engineering applications demand washers with dimensions or features that simply cannot be achieved by punching. Jamnagar Brass Components specialises in CNC-machined brass washers — turned from bar, rod, or tube to any inside diameter, outside diameter, and thickness your application requires. We serve US, UK, European, and Australian OEM customers supplying precision assemblies in instrumentation, hydraulics, valves, plumbing, and electrical equipment.

When Are Machined Brass Washers Needed?

Machined washers are specified when the required dimensions fall outside standard stamped washer tables, when tight tolerances (±0.02 mm on ID/OD) are needed, when the washer must carry a face groove, O-ring groove, or chamfer, or when the washer must be from a specific bar alloy (e.g. free-machining brass CZ121 or leaded brass) rather than strip. Common scenarios include precision instrument spacers, valve seat washers, hydraulic union seals, and electrical insulation standoffs.

Brass Alloy Grades for Machined Washers

Grade Name	UNS (USA)	EN (Europe)	BS (UK)	Composition	Best For
Free-Machining Brass	C36000	CW603N	CZ121	61Cu–35.5Zn–3.5Pb	High-speed CNC machining
Naval Brass	C46400	CW712R	CZ112	60Cu–39.2Zn–0.8Sn	Marine/seawater environments
Cartridge Brass	C26000	CW505L	CZ106	70Cu–30Zn	Ductile, corrosion resistant
Standard Brass	C28000	CW508L	CZ108	60Cu–40Zn	General purpose, economical
DZR Brass	C35330	CW602N	CW602N	61Cu–37Zn–2Pb–0.07As	Hot water, dezincification resistance

Types of Machined Brass Washers We Produce

Plain Flat Machined Brass Washers

Turned flat washers in any ID, OD, and thickness, with face-ground parallelism to 0.01 mm on precision versions. Available in any combination of chamfer, radius edge, or sharp corner per drawing. Ideal for instrument assemblies and precision valve stacks.

Stepped and Shouldered Brass Washers

Washers with a raised boss or shoulder (cup washers / shoulder washers) for locating purposes in valve bodies, meters, and manifold assemblies. The shoulder provides precise axial location that a flat washer cannot.

Brass Sealing Washers with O-Ring Groove

Machined brass washers with a face O-ring groove to DIN 3869 or custom depth/width, providing reliable sealing on hydraulic and pneumatic fittings at pressures up to 350 bar. Groove dimensions held to ±0.05 mm.

Thick Brass Spacer Washers

Where panel gaps, standoffs, or shaft spacers are needed in washer form factor — typically 5 mm to 50 mm thick — we machine spacer washers from brass bar with parallel faces and precise OD/ID to function as both spacer and load-bearing washer.

Brass Taper Washers

Machined tapered (angled face) washers for structural beam flanges, crane and hoist equipment, and inclined joint faces, ensuring full bolt bearing contact on angled surfaces.

Large Diameter Brass Washers

For flange joints, architectural installations, and heavy machinery — OD up to 300 mm — turned from large-diameter brass bar or disc blanks when stamping tooling is impractical for such sizes.

Applications of CNC Machined Brass Washers

• Valve and actuator component stacks
• Hydraulic and pneumatic sealing applications
• Water meter and flow instrument assemblies
• Gas fitting and regulator components
• Precision instrument and gauge housings
• Electrical cable entry and gland components
• Architectural and curtain wall facade fixings
• Marine hardware and underwater fittings

Why Choose Jamnagar Brass Components for Machined Brass Washers?

• No standard size restrictions — ID from 1 mm, OD up to 300 mm, thickness from 0.5 mm
• Tight tolerance capability — ±0.02 mm on ID/OD, ±0.01 mm on face parallelism
• Wide alloy selection — CZ121, CZ108, CZ112, DZR brass, and more
• Complex features — grooves, chamfers, shoulders, cross-holes, knurling on request
• ISO 9001:2015 quality — CMM inspection on critical dimensions
• Low MOQ — from 25 pcs for custom machined washers
• Fast turnaround — standard machined washers delivered in 2–3 weeks
• Cost advantage — 50–60% lower cost than European or US domestic machining

Frequently Asked Questions — Machined Brass Washers

Q1: When should I specify a machined washer instead of a stamped washer?

Specify machined washers when your dimensions fall outside standard stamped washer tables, when tolerances tighter than 0.1 mm are required on OD or bore, when the washer needs special features such as O-ring grooves, chamfers, shoulders, or taper faces, when the alloy is only available in bar form, or when order quantities are too low to justify stamping tool costs.

Q2: What is the tightest tolerance you can hold on a CNC machined brass washer?

In production we routinely hold plus or minus 0.02 mm on both bore and OD for CNC turned brass washers. With post-turning cylindrical grinding, IT5 to IT6 tolerance class is achievable, equivalent to plus or minus 0.008 to 0.013 mm on mid-range sizes. Face parallelism of 0.01 mm is standard on precision instrument washers. CMM inspection reports are available on request.

Q3: Can you supply machined brass washers in DZR brass for hot water applications?

Yes. We supply machined washers in DZR (Dezincification Resistant) brass conforming to BS EN 12165 and CW602N, suitable for potable water fittings and WRAS-approved plumbing assemblies. DZR brass is specified in the UK Water Regulations and increasingly by US plumbing codes for brass components exposed to hot water above 60 degrees Celsius, where standard brass can suffer dezincification.

Q4: What size range is available for CNC machined brass washers?

We machine brass washers from 3 mm OD with 1 mm bore up to 300 mm OD with large bore sizes. Thickness can range from 0.5 mm to 50 mm. For very large diameter washers above 150 mm OD, we machine from large-diameter brass disc blanks or saw-cut discs. There are no standard size restrictions for machined washers since each is turned to order from bar stock.

Q5: What is a stepped or shouldered brass washer and when is it used?

A stepped washer has a raised boss or shoulder on one face, providing positive axial location in a counter-bore or pocket. The shoulder allows the washer to centre itself precisely in a bore, preventing lateral movement. They are used in valve assemblies, meter housings, manifold stacks, and instrument assemblies where a flat washer would not locate reliably and a spacer would add unnecessary height.

Q6: Can you machine brass washers with O-ring grooves?

Yes. O-ring groove washers are machined with a face groove to DIN 3869 or customer-specified dimensions to create a static face seal on hydraulic and pneumatic fittings. Groove depth and width are held to plus or minus 0.05 mm and the groove bottom radius is precision-turned to prevent O-ring damage. Working pressures up to 350 bar are achievable with the correct O-ring compound and groove dimensions.

Q7: What alloys are available for CNC machined brass washers?

Available alloys include: CZ121 (C36000, free-machining brass with 3% lead, fastest to machine), CZ108 (C28000, 60/40 general purpose), CZ106 (C26000, 70/30 cartridge brass, most ductile), CZ112 (C46400, naval brass for seawater), DZR brass (CW602N for hot water), and CZ120 (C35000 medium-leaded brass). We can also machine in bronze, stainless steel, and aluminium if required.

Q8: Do you supply taper washers and why are they used?

Yes. Taper washers are machined with an angled face (typically 1 in 8, 1 in 14, or custom angle) to compensate for inclined surfaces on structural steel beam flanges, crane girder connections, and pipe support brackets. A taper washer ensures the bolt bears uniformly across its full face contact area, preventing bending stress in the bolt shank on non-perpendicular joint faces.

Q9: Can you supply large diameter brass washers not available off the shelf?

Yes. This is where machined washers are essential. Stamped washers above approximately 80 to 100 mm OD are not economically produced due to tooling cost and press tonnage requirements. We machine brass washers from 100 mm to 300 mm OD from large bar or disc blanks to any bore and thickness dimension. These are common for flange face seating washers, pipe support plates, and architectural fixings.

Q10: What is the minimum order for CNC machined brass washers?

We accept orders from 25 pieces for most machined washer types. For complex washers with multiple features such as O-ring grooves and counter-bores, minimums from 50 pieces are typical. For precision-ground washers requiring additional operations, 100 pieces is the minimum for economic production. There is no minimum for prototype or first-article orders where 1 to 5 pieces are acceptable at prototype pricing.