Product Category
Ra 0.1µm · ±0.05° · ≤0.003mm Conc. · IT5
VLS / 001 — 008
Precision Ground
Valve Seats
Precision CNC turned and ground valve seats — seating surface Ra 0.1 µm, seat angle tolerance ±0.05°, OD/ID concentricity ≤ 0.003 mm. Hard chrome or ceramic-coated options. For ball valves, check valves, needle valves, and relief valves.
Ra 0.1µm
Seating Surf.
±0.05°
Seat Angle
≤0.003mm
Concentricity
PART DWG · VLS-000 BALL VALVE SEAT · SUS440C HRC58
ISO 9001 · HONED Ra 0.1µm
Ball Above Seat
Cone Angle 45°
Ball · Relief · Check · Needle · Aero
Use Cases
SUS440C · 316L · Stellite · Inconel · Ti
Materials
48hr Quote · 6-Day Proto
Service
Ra 0.1µm
Seating Surface
leakage-critical finish
leakage-critical finish
±0.05°
Seat Angle
tolerance class
tolerance class
≤0.003mm
OD/ID Concentricity
leakage control
leakage control
6 Days
Fastest Delivery
prototype orders
prototype orders
Machining Challenges
Valve Seat Machining Challenges
The valve seat is the single most critical sealing surface in a valve assembly — its surface finish, angle accuracy, and concentricity determine the leak rate in the closed position.
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Seating Surface Ra 0.1µm
The seating surface must be smooth enough to form a leak-tight contact with the ball, needle, or poppet. Ra 0.1 µm is standard for metal-to-metal seating — achieved by dedicated honing or superfinishing after turning.
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Seat Angle & Concentricity
The seat cone angle must match the mating valve element to ±0.05°. Concentricity between the seat ID, seating surface, and OD must be ≤ 0.003 mm — any eccentricity causes one-sided contact and localised leakage.
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Press Fit & Housing Interface
Valve seats are press-fitted or threaded into valve bodies. The OD press-fit diameter must be accurate to IT5 — preventing seat loosening under pressure cycling or thermal shock.
Our Work
Request Similar Part →
Valve Seats We've Made
Real CNC machined projects — inspected and delivered.
Stellite 6 · High Temp
Capabilities & Tolerances
What We Can Deliver
Typical specifications for this product type. Confirm exact requirements at enquiry.
| Seating surface Ra | 0.1 µm standard (honed) |
| Seat angle tolerance | ±0.05° |
| OD/ID concentricity | ≤ 0.003 mm |
| OD press-fit tolerance | IT5 (h5/h6) |
| Materials | SUS440C, Stellite, Inconel, Ti |
| Inspection | CMM + profilometer seat Ra |
| Surface treatment | Hard chrome, ceramic, Stellite hardfacing |
| Seat angle range | 15°–90° standard; any angle available |
| Lead time (proto) | 6–9 days |
| Lead time (batch) | 10–16 days |
| Matched pairs | Seat + ball/needle available |
| Pressure test | Leak test at 1.5× rated pressure |
How It Works
From Drawing to Finished Part
Upload your drawing — DFM review, machining, pressure/leak test if required, and shipping within agreed lead time.
01
Upload Drawing
STEP, DXF, PDF. Include channel specs, thread standards, and sealing requirements.
02
DFM & Quote
Free DFM review — channel access, deburring feasibility, sealing surface strategy. Quote in 48 h.
03
Machine & Test
CNC machining, deburring, cleaning, CMM inspection, pressure/leak test as specified.
04
Ship Worldwide
Inspection report + test records enclosed. DHL / FedEx / sea freight.
Reviews
Trusted by Engineers Worldwide
★★★★★
"Deep cross-drilled channels were deburred perfectly — zero burrs found at our incoming inspection. Leak test passed first time. Delivery exactly on schedule."
MK
Martin K.
Hydraulic Systems Engineer · Germany
★★★★★
"We source precision valve bodies and manifold blocks from HXC. Bore coaxiality is consistently within 0.005 mm, sealing surface Ra verified on every batch."
SL
Sophie L.
Procurement Manager · France
★★★★★
"HXC understood the cleanliness requirements for our semiconductor gas distribution plates immediately. Documentation package was complete and traceable."
JT
James T.
Process Engineer · Taiwan
FAQ
Frequently Asked Questions About Valve Seat Machining
Engineering and procurement questions answered by our team.
Metal-to-metal valve seats: Ra 0.1 µm on the seating surface — achieved by a dedicated honing pass after turning. For ultra-low leak rate applications (gas service, high-pressure cryogenic): Ra 0.05 µm with lapping. Elastomer-seated valves: Ra 0.8–1.6 µm is acceptable. Surface finish measured by profilometer at 3 angular positions on the seat cone.
Seat angle is measured by CMM using a precision sphere probe tracing the seat cone — the cone angle is computed from the point-cloud data and compared to nominal. Tolerance ±0.05° (3 arc-minutes). For high-accuracy check valves: ±0.02° achievable with additional measurement and correction passes.
Stellite 6 hardfacing: deposited by plasma transferred arc (PTA) or laser cladding on 316L or 42CrMo4 base, then ground to Ra 0.1 µm. Used for steam, hot oil, and high-cycle valves. Inconel 718: for high-pressure, high-temperature gas service. Ceramic coating (Al₂O₃ or WC): for corrosive or abrasive fluid seats. HXC machines all substrate materials; coating is applied by our process partners.
Yes — matched pairs are produced where the ball or needle is ground to the specific seat geometry. Contact angle is verified by ink-transfer check — 360° continuous contact required. Matched pair inspection report provided.
Press-fit seats: OD machined to IT5 (h5/p5) — appropriate interference for the housing bore material and operating temperature. Threaded seats: thread class 4H/6g, verified by gauge. Flared and O-ring retained seats are also available. Specify the retention method on your drawing and we confirm compatibility during DFM review.
Yes — hard chrome plating (15–35 µm, HRC 68–72) is available for hydraulic valve seats requiring high wear and corrosion resistance. PVD TiN or DLC coatings are available for low-friction applications. All coatings are applied by HXC's coating partners and dimensional verification is performed after coating.
(1) CMM measurement of OD, ID, concentricity, and seat angle; (2) Profilometer measurement of seating surface Ra; (3) Hardness check (Rockwell or Vickers); (4) Visual inspection under 10× magnification for seat surface defects; (5) Leak test at 1.5× rated pressure (matched pair). All results reported.
Prototype: 6–9 days. Batch (100–1,000 pcs): 10–16 days. Stellite-hardfaced seats: add 4–6 days.
Get a Quote
Send Your Drawing.
Get a Quote.
Every enquiry includes a DFM review — tolerance feasibility, material confirmation, and process approach confirmed before production starts. MOQ 1 piece.
24hr
Quote Response
MOQ 1
Prototypes OK
ISO
9001:2015
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DFM Review on Every Enquiry
Tolerance feasibility, fixturing strategy, and material confirmation. Specific, actionable feedback — not generic pushback.
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First Article Inspection — Standard
FAI report on every new run. Material certs and surface treatment certs included with every shipment.
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Same Process: Prototype to Production
Process plan from your prototype applies to production batches. No re-qualification when you scale.
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3 / 4 / 5-Axis CNC + Turning
Complex structural parts, shafts, housings, and transmission components. Metals and engineering plastics.
ISO 9001:2015
3/4/5-Axis Milling
CNC Turning
CMM Inspection
Global Delivery