Selection And Advantages Of Kf Aluminum Vacuum Clamps

A KF aluminum CNC vacuum clamp connects KF flanges with a centering ring and O-ring to create a vacuum-tight seal. CNC machining ensures consistent clamping force and eliminates casting porosity. The hinged clamp applies uniform radial force around the flange circumference when tightened. This design achieves leak rates as low as 1×10⁻⁸ Torr and enables tool-free assembly, making it standard in semiconductor fabrication and high-vacuum systems.

How does a KF clamp achieve a high-vacuum seal

1. A centering ring with an O-ring is placed between two KF flanges.

2. The clamp is positioned around the flanges and the hinged halves are closed.

3. The wing nut is tightened to apply uniform radial compression.

4. The O-ring is compressed to achieve leak rates as low as 1×10⁻⁸ Torr.

Common Application Pitfalls

• 💡 Mismatched flange sizes → KF25 on KF16 will not seal. → Use matching sizes.

• ❌ Over-torquing → Distorts flanges or damages O-ring. → Follow torque specifications.

• 📌 Wrong O-ring material → FKM is standard; verify temperature and chemical compatibility.

• ⚡ Misaligned centering ring → Creates leak paths. → Ensure centering ring is seated correctly.

KF Clamp Sizes – Matching Clamp to Flange

KF clamps are designated by flange size, with the numerical value referring to nominal inner diameter in millimetres.

A kf25 clamp balances flow capacity with compact dimensions. The kf 25 clamp is compatible with NW-25 flanges. A kf40 clamp is specified for larger lines and primary vacuum lines. A kf 16 clamp suits small-bore instrumentation and gas injection lines.

CNC-Machined vs Cast Clamps – Why It Matters

CNC machining produces clamps with consistent dimensions and eliminates casting porosity. Smooth surface finish reduces particle generation—critical in semiconductor and vacuum applications.

Advantages of CNC-machined clamps:

• Consistent clamping force across all units

• No casting porosity or surface imperfections

• Smooth surfaces reduce particle generation

• Integral lock washers prevent galling

Materials – Aluminum vs Stainless Steel

Installation and Sealing Mechanism

Installation steps:

• Align the two KF flanges and place the centering ring between them.

• Position the clamp around the flange assembly and close the hinged halves.

• Tighten the wing nut by hand until snug, then apply specified torque.

Performance data:

• Leak rate: ≤ 1×10⁻⁸ Torr (helium)

• Temperature range: -40°C to +150°C with FKM O-rings

• Vacuum rating: Atmosphere to 10⁻⁸ Torr

Applications

Semiconductor: Etch and deposition tools, load-lock systems, gas delivery lines. 304 stainless steel, FKM O-rings, sizes KF16, KF25, KF40, KF50.

R&D and pilot plants: General vacuum systems. Aluminum clamps, FKM O-rings.

Analytical instrumentation: Small-bore gauge and gas injection lines. KF 16 clamp for small-diameter connections.

KF aluminum CNC vacuum clamps provide fast, tool-free connections for high-vacuum systems. Sizes KF16, KF25, KF40, and KF50 cover applications from small-bore instrumentation to large transfer lines. CNC machining ensures consistent clamping force and eliminates casting defects. Aluminum suits general vacuum service; stainless steel is required for semiconductor cleanrooms. Leak rates ≤1×10⁻⁸ Torr.

KF Aluminum CNC Machined Vacuum Clamp

• KF Aluminum CNC Machined Vacuum Clamp is an essential part of vacuum fittings, it follow ISO-KF standards. Flange size from KF-10 to KF-50, offered for tube diameters from 1/2″ to 2″. Used especially for high strength, corrosive, high torque, high heat and low temperature applications. Machined from solid bar for greatly increased strength. They are commonly used to build foreline vacuum plumbing and process systems. A circumferential clamp and centering ring form the vacuum seal between the connecting flanges. The centering ring contains a rubber elastomer o-ring. They are made of aluminum.

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