CNC Machined End Caps
End caps and covers with sealing grooves, bored to fit the housing they close.
End caps that have to seal and locate, so the spigot and the bore are cut in one setup. The groove for the O-ring is machined after the spigot, off the same datum.
How we make it: Precision CNC machining service →
3–5 weeks
10 pieces
ISO 9001:2015
Technical Specifications
| Parameter | Value | Unit |
|---|---|---|
| Spigot tolerance | h7 | - |
| Groove position | ±0.05 | mm |
| Face flatness | 0.02 | mm |
| Diameter range | Ø30–Ø600 | mm |
| Surface roughness | Ra 1.6 | µm |
| O-ring grooves | Machined to suit | - |
Available Materials
Typical Applications
- Motor end caps
- Pump covers
- Gearbox covers
- Cylinder end caps
- Bearing retainers
Surface Finishes
- Anodise
- Painted
- Passivate
- Machined sealing faces
- Zinc plating
Industries Served
- Industrial Equipment
- Hydraulics & Pneumatics
- Automotive & EV
- Marine
- Energy & Oil & Gas
What drives the price of this part
Derived from the callouts on this page. Where a driver is not on the drawing, it is not on this list.
- Tolerance
- Spigot tolerance at h7 is the tightest callout this family carries. Tightening a callout is a process decision, not a machining decision: below the standard ±0.005 mm the work moves to grinding or jig boring, and the price moves with it.
- Part size
- Diameter range at Ø30–Ø600 mm decides which machine the part lands on and how many setups it needs. Size is the driver buyers most often leave out of a first enquiry, and it is the one that changes the quote fastest.
- Surface finish
- Surface roughness at Ra 1.6 µm. Every step below the ordinary as-machined Ra 1.6 µm adds a finishing pass; a callout on a face nobody touches is the most common over-specification we quote.
- Material
- The first material listed, Aluminium 6082-T6, rates 9/10 on our machinability scale at 95 HB. On this shop's scale a harder alloy means slower passes and more tool changes, and that is cycle time the quote has to carry.
- Order size
- Minimum order is 10 pieces, so on a first order setup and programming are spread over very few parts and they are most of the price. Repeat orders at the same quantity are cheaper without anything on the drawing changing.
See how cycle time is calculated in the machining time calculator and what else moves a price in the cost driver reference.
How these parts are inspected
Matched to the callouts above and the instruments actually on the floor.
- Coordinate measuring machine (Zeiss CONTURA G2, two machines, GR&R 8.4% on the critical feature)
- Dimensional report against the drawing, with a 100% check on critical features rather than a sample
- Certificate of conformance and the mill certificate with every shipment
- Surface roughness tester (Mitutoyo) against the Ra callout
- Bore gauges and an optical comparator for hole position and edge form
The full equipment list, with counts, is on the capability page; the inspection sequence is on quality and inspection.
Questions buyers ask
- Why cut the O-ring groove in the same setup as the spigot?
- So the groove is concentric with the fit. Cut in a second operation and the seal sits slightly off centre, which is enough to leak on a shaft seal.
Related part families
CNC Machined Housings
Machined housings with bored seats and sealing faces, held coaxial to 0.01 mm.
CNC Machined Flanges
Flanges with drilled bolt circles and machined faces, to ANSI, DIN and JIS patterns.
Bearing Housings
Machined housings with bearing seats bored to H7, coaxial to 0.01 mm across the pair.