Conflat (CF) Gasket
100% reliability — Money back guarantee
- World’s largest selection – 46 sizes in stock
- Copper – Nickel – Aluminum – all annealed
- Precision machined – 100% guaranteed
- Small quantities or OEM
- Same day shipping to US or EU
- All CF gaskets manufactured by Bostec in the USA
Full section cutaway assembly of two CF flanges crushing a CF gasket to completion and demonstrating that the HiRim® raised perimeter sits without interference in the free space of the gland.
Sizing Chart
45 Sizes from 13mm to 463mm / HiRim & Conventional CF Gaskets
Dimensions per ASTM E2734/E2734M - 10; Licensed to Thomas Kristy, ANSI Order X_354097
Dimensions per ASTM E2734/E2734M - 10; Licensed to Thomas Kristy, ANSI Order X_354097
Full section cutaway assembly of two CF flanges crushing a CF gasket to completion and demonstrating that the HiRim® raised perimeter sits without interference in the free space of the gland.
Most Sizes in Stock for Same-Day Shipment
HiRim® CF Gaskets: A Radically Better CF Gasket, Designed for Super-UHV
Bostec Conflat (CF) gaskets are precision machined so they fit properly and are 100% reliable. They won’t contaminate your processes with unwanted burrs, abrasive contaminants or manufacturing debris. ID edge transitions are smooth to minimize entrapped particles and the flat (mating) surfaces are machined with a precise circular ring pattern, (flat to 6Ra,) which helps the knife edge seat into the gasket for a perfect seal.
Tolerances are held to tenths and all surfaces are “as-machined”—not polished or otherwise modified post-machining. Abrasives are not used. Our inspection process ensures no radial scratches are visible at 10X magnification and the gaskets are free from inclusions and other blemishes. In short, these are the finest CF gaskets manufactured anywhere!
Full section cutaway assembly of two CF flanges crushing a CF gasket to completion and demonstrating that the HiRim® raised perimeter sits without interference in the free space of the gland.
HiRim CF Gaskets Outperform Conventional CF Gaskets
- Self-protecting—won’t scratch
- Easy to handle in production environments
- Self-centering
- Easy to install and remove
- Directly interchangeable—fits all CF flanges
- Guaranteed 1 x 10-11 leak rate
- 100% reliable—100% yield, guaranteed!
The highest quality CF gaskets manufactured anywhere, bar none!
HiRim® CF Gasket Advantages
Interchangeable with Conventional CF and DN Gaskets
HiRim gaskets are self-protecting, easy to install and remove, self-centering and dimensionally identical to conventional CF gaskets. Drop them directly into your existing flanges—no alterations necessary!
HiRim gaskets are precision machined so they fit properly and are 100% reliable. They won’t contaminate your processes with unwanted burrs, abrasive contaminents or manufacturing debris. ID edge transitions are smooth to minimize entrapped particles and the flat (mating) surfaces are machined with a precise circular ring pattern, (flat to 6Ra,) which helps the knife edge seat into the gasket for a perfect seal. Tolerances are held to tenths and all surfaces are “as-machined”—not polished or otherwise modified post-machining. Abrasives are not used. Our inspection process ensures no radial scratches are visible at 10X magnification and the gaskets are free from inclusions and other blemishes. In short, these are the finest gaskets manufactured anywhere!
HiRim CF gaskets are a proprietary development of Bostec Engineering, first released in 2016 conforming to SEMI F19 and ASTM B46.1.
Self-protecting – won’t scratch.
Slide them across a table or drop them on the floor; the raised edge keeps the gasket surface safe from scratches or damage.
Easier to install and remove.
Easy placement in vertical assemblies.
Bostec CF Gaskets are Precision Machined – Not Stamped
Most components in any modern UHV process are precision machined to tight tolerances with highly polished surface finishes. Your gaskets should be no different! Precision gaskets fit properly, are 100% reliable and do not contaminate with unwanted burrs, abrasive contaminants or manufacturing debris.
Bostec H-Seals are machined on all surfaces and are completely free of burrs. Gasket faces have precise machining grooves in an annular ring pattern to ensure the knife edge seats into the gasket.
Surfaces are less than Ra 0.6 (circular) and delivered “as-machined”—not polished or otherwise modified post- machining. No abrasives are used.
Our inpection process ensures no radial scratches are visible at 10X magnification, and the gaskets are free from surface inclusions and other blemishes.
In the world of super-UHV, the cost of a single failed gasket is 1000X the cost of the gasket itself. It makes no sense to use inferior gaskets and risk failure.
Common Problems with Stamped CF Gaskets
Conflat flanges and gaskets were developed in the early 1960’s before the rigors of ultra-pure and super-UHV were commonplace. The original design was a simple flat gasket punched from sheets of copper, keeping costs low. However, stamping is a crude process, leaving burrs, shear-tear and rolled-over edges on the gaskets. These defects violate ultra-pure standards specifying smooth surfaces and fully swept flow paths to minimize entrapped particles.
To remove jagged edges and burrs, stamped gaskets are typically tumbled in an abrasive medium and the medium itself becomes an embedded contaminant in the gasket surface. Tumbling simply rolls burrs over, as opposed to removing them. This traps even more contaminants to polute processes.
Stamped gaskets are produced from rolled sheet material that is, by nature, uneven and micro-pitted from the rollers. Thus, the finished gasket has a contaminated, micro-pitted surface that can itself trap particles.
Stamping is an imprecise process. CF design clearances are tight—only 0.0035″/0.09 side to side. Shear tear and edge rollover make for sloppy tolerances so CF gaskets don’t always fit properly.
In contrast, Bostec gaskets are precision machined to high tolerances with perfect surface finishes in order to be 100% reliable.
Bostec CF Gaskets Magnified
Qualifying Bostec CF and HiRim Gaskets at CERN
Easy to Order by Intuitive Part Names
Bostec’s extensive offering in vacuum gaskets features an intuitive part numbering format, allowing the customer to identify the product by the characters contained within the part number.
