Custom machined part
Machined valve spools
- Turned to your drawing
- Lands, grooves & edges
- Materials
- Plastic or soft metal
- Starting point
- Drawing or old spool
- Quantity
- One part to production
CNC-turned spools for directional and selector valves, in engineered plastics, aluminum, brass or bronze. Made to your drawing or from your old spool, from one part to production runs.
- ±0.002"–±0.005" on critical dimensions
- Family owned in Aurora since 1986
- Expedited service for breakdowns
How a spool switches ports
Shift the spool, change the flow path
A spool is a shaft with raised lands and grooves between them. As it shifts in its bore, the lands cover and uncover ports. Pick a position to see how the ports connect.
Spool shifted one way
- P A Supply flows out to work port A.
- B T Work port B returns or exhausts.
Spool shifted the other way
- P B Supply now flows out to work port B.
- A T Work port A returns or exhausts.
- P supply
- A, B work ports
- T return or exhaust
The lands do the switching. Their diameters, widths and edges, and where the ports sit in the bore, are what we machine to.
What defines the spool
The spool and its bore, together
Overall length and diameter aren’t enough. These are the features we machine to.
- Lands Diameter and width of each raised land.
- Grooves Diameter and width between the lands.
- Edges Metering or shut-off edges, sharp or chamfered as drawn.
- Ends Actuation, centering-spring or detent features, threads and flats.
- Bore and ports The mating bore and where each port sits along it.
- Stroke Each shift position, and the travel between them.
Running clearance is set by your drawing or the valve maker’s spec. We confirm what we can hold with the quote.
Getting a quote
Start with what you have
Any one of these is enough to get a quote started. Pick yours to see what helps.
Send the drawing and we machine to it.
- Quantity
- Material, if specified
- Running clearance
Upload drawings, CAD files or photos on the quote form.
Send the old spool, with the valve body if you can.
- The fluid or gas it runs on
- What went wrong
- Quantity
Upload drawings, CAD files or photos on the quote form.
Send what you know. We’ll ask for the rest.
- Valve make and model
- Circuit type
- Photos of the spool
Upload drawings, CAD files or photos on the quote form.
Materials for spools
Plastic or metal, chosen for the bore
A close-running spool needs a material that holds its size in service. Low moisture uptake and wear resistance matter more here than on most parts.
Plastics
- PET-P (polyester) Very low moisture uptake, good wear and low thermal expansion. A common choice for close-running spools.
- Acetal Stiff and dimensionally stable for many air and water valves.
- PEEK Strength, heat and chemical resistance with little creep.
- PAI (polyamide-imide) Very hard and wear-resistant, for demanding spool and sleeve duty.
- Nylon Tough, but it takes on moisture, which matters on a close-running spool.
Metals
- Aluminum, brass & bronze When the valve calls for a metal spool, we machine those too.
Machined in Aurora
How your spools are made
±0.002"–
±0.005"
On critical dimensions, depending on the material.
- CNC turned so the lands run true along the spool, with ends, flats and cross-holes added on live-tooled turning centers.
- O-rings and seals fitted before shipping, ready to install. Assembly service
- Specs and CAD files kept, so the next batch matches the last.
Evaluating a supplier? See the shop and how we check the work.
Where machined spools are used
Valve & fluid handling- Food & beverage filling Spools and pistons in liquid-filling machines
- Air-operated pumps The spool and sleeve that shift a diaphragm pump
- Pneumatic valves Air valves where oil-free, light parts matter
- Fire protection Foam-proportioning valves
Buyer questions
Valve spool FAQs
Something else? Call (630) 904-2525.
Yes, the old spool can start the job. Send it with the valve body if you can, and we’ll work from both.
Both can work. Plastic spools are used where running without lubrication, corrosion resistance or low weight matter. Metal suits where the valve calls for it. Tell us the fluid, pressure and current material, and we’ll suggest suitable options. We machine aluminum, brass and bronze as well as plastics.
We hold ±0.002" to ±0.005" on critical dimensions, depending on the material. Running clearance comes from your drawing or the valve maker’s spec. We confirm the land diameters and clearance we can hold with the quote.
Timing depends on the spool, material and quantity, and comes with your quote. For an emergency breakdown, ask about our expedited service.
Not a spool?
Find the right part
We machine almost any plastic part. If yours isn’t listed, describe it in a quote request.
Standard quote
Ready to send your spool details?
Experienced help from your first quote to the finished part.