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DN35CF-DN40CF (2.75" OD) 316LN SS Standard ConFlat® (CF) Flanges DN35CF-DN40CF (2.75" OD) 316LN SS Standard ConFlat® (CF) Flanges 1

DN35CF-DN40CF (2.75" OD) 316LN SS Standard ConFlat® (CF) Flanges

The CF (ConFlat) flange is the most widely used for high vacuum and UHV applications. Many gauges, instruments, accessories and feedthroughs are available on this flange system.

The seal mechanism is a knife-edge that is machined below the flange's flat surface. As the bolts of a flange-pair are tightened, the knife-edges make annular grooves on each side of a soft metal gasket. The extruded metal fills all the machining marks and surface defects in the flange, yielding a leak-tight seal. The CF seal operates from 760 torr (103 mbar) to < 1 x 10-13 Torr (< 1.3 x 10-13 mbar), and within the temperature range -196° C to 450° C (depending on material). Flange sizes in North America are normally referenced by their outside diameter (O.D.). However, in Europe and much of Asia, the nominal internal diameter (nominal I.D.) of the largest tube that can be welded to a bored flange is usually referenced in their nomenclature.

ConFlat flanges are offered in four versions:

  • Fixed flange: is a one piece design where the bolt-hole orientation is fixed with respect to that fitting.
  • Rotatable flange: is comprised of two parts, an inner weld ring and outer bolt ring. This enables the bolt ring to rotate about the inner weld ring.

Both Fixed and Rotatable flanges are available with your choice of clearance-holes or tapped holes.

  • Clearance-holes: Are through-holes that allow adequate clearance for bolts to go through both flanges and secured by nuts or plate nuts.
  • Tapped holes: Are imperial or metric threaded holes machined through the flange. This allows a clearance-hole flange to be connected without the need for nuts or plate nuts. Be aware of a components bolt hole orientation when selecting tapped flanges.

316LN Stainless Steel Features:

  • Harder than their 304L counterparts (170 Brinell Hardness) making them ideal for frequently dismantled chamber ports
  • Electro-slag Remelt (ESR) to improve grain homogeneity and remove gross macro segregation
  • Lower magnetic permeability (µ ≤ 1.005 vs. 1.03 for 304L SS) for applications sensitive to magnetic materials
ISO Standard KJLC flanges & gaskets are compatible with ISO3669-2017, but more importantly are compliant to the stricter requirements of E2734/E2734M – 10.

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Ordering Table

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Flange Selection Guide
With a variety of flanges to choose from, the Flange Selection Guide is designed to help you find one to meet your vacuum requirements. Shop Now!
Can't find the flange you need or want a custom configuration? Please call us at +1 412 387 9200 or email international@lesker.com with your inquiry.

Accessories Table

Description For Per Package Manual
VacuCADSM
Part Number Price In Stock Add Item
Description For Per Package Manual
VacuCADSM
Part Number Price In Stock Add Item
Protective Cover, DN35-DN40CF (2.75" OD) Flange All 2-3/4" (DN35-DN40CF) Flanges 1
N/A
F0275CAP
$1.15 In Stock
Gasket, Copper, DN35CF-DN40CF (2.75" OD) Flange, 1.895" OD, 1.451" ID, (10) Per Package All 2-3/4" (DN35-DN40CF) Flanges 10
(please log in)
GA-0275
$27.35 In Stock
Gasket, Copper, DN35CF-DN40CF (2.75" OD) Flange, Large Bore, 1.895" OD, 1.528" ID, (10) Per Package All 2-3/4" (DN35-DN40CF) Flanges 10
(please log in)
GA-0275LB
$27.35 In Stock
Gasket, Copper, Silver Plated, DN35CF-DN40CF (2.75" OD) Flange, Large Bore, 1.895" OD, 1.528" ID, (1) Per Package All 2-3/4" (DN35-DN40CF) Flanges 1
(please log in)
GA-0275LBNSP
$5.45 In Stock
Gasket, Copper, Silver Plated, DN35CF-DN40CF (2.75" OD) Flange, 1.895" OD, 1.451" ID, (1) Per Package All 2-3/4" (DN35-DN40CF) Flanges 1
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GA-0275NSP
$5.45 In Stock
Hex Bolt & Washer Kit, Stainless Steel, (25) 1/4-28 x 0.875" Long Hex Bolts & (25) Flat Washers 2-3/4" (DN35-DN40CF) Tapped CF Flanges 25
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HBK25028088
$15.60 In Stock
Hex Bolt & Washer Kit, Stainless Steel, (25) M6 x 35mm Long Hex Bolts & (25) Flat Washers 2-3/4" (DN35-DN40CF) Tapped CF Flanges 25
N/A
HBKM6X35
P.O.R. Contact KJLC for Availability
Hex Bolt, Nut & Washer Set, Stainless Steel, (25) 1/4-28 x 1.38" Long Hex Bolts, (25) Hex Nuts, & (50) Flat Washers 2-3/4" (DN35-DN40CF) Through-hole CF Flanges 25
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HBS25028138
$30.50 In Stock
Hex Bolt, Nut & Washer Set, Stainless Steel, (25) M6 x 35mm Long Hex Bolts, (25) Hex Nuts, & (50) Washers 2-3/4" (DN35-DN40CF) Through-hole CF Flanges 25
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HBSM6X35
$17.70 In Stock
Plate Nut, Bolt & Washer Set, Stainless Steel, DN35CF-DN40CF (2.75" OD) Flange, (24) 1/4-28 x 1.25" Long Hex Bolts, (12) 1/4-28 Plate Nuts, & (24) Flat Washers 2-3/4" (DN35-DN40CF) Through-hole CF Flanges 24 Hex Bolts/12 Plate Nuts
N/A
PNB-0275
$41.25 In Stock
Plate Nut, Bolt & Washer Set, Stainless Steel, DN35CF-DN40CF (2.75" OD) Flange, (24) M6 x 35mm Long Hex Bolts, (12) M6 Plate Nuts, & (24) Flat Washers 2-3/4" (DN35-DN40CF) Through-hole CF Flanges 24 Hex Bolts/12 Plate Nuts
N/A
PNB-0275M
$52.00 In Stock
Gasket Clips, For All Conflat (CF) Flange Sizes, (10) Per Package All 2-3/4" (DN35-DN40CF) Flanges 10 Download PDF
N/A
VGC0275S
P.O.R. In Stock
Gasket, Copper, Annealed, DN35-DN40CF (2.75" OD) Flange, (5) Per Package All 2-3/4" (DN35-DN40CF) Flanges 5
(please log in)
VZCUA38
$21.45 In Stock
Gasket Removal Tool, For All Conflat (CF) Flange Sizes All 2-3/4" (DN35-DN40CF) Flanges 1
N/A
VZGRT
$38.20 In Stock
Thread Lubricant, 4 Ounce Tube All 2-3/4" (DN35-DN40CF) Flanges 1
N/A
VZTL-4OZ
P.O.R. In Stock
Gasket, FKM, Molded, DN35-DN40CF (2.75" OD) Flange, 1.90" OD, 1.40" ID, (2) Per Package All 2-3/4" (DN35-DN40CF) Flanges 2
(please log in)
VZVIT38
P.O.R. In Stock
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Contact Us - DN35CF-DN40CF (2.75" OD) 316LN SS Standard ConFlat® (CF) Flanges