MCI-HF (Metal C-Ring highflex spring energized for internal pressure application)

To the overview
Metal C-Ring

Internal pressure application


For internal pressure applications the outer diameter of the ring ODR is calculated as follows:

ODR = OD - Z

CSR Nominal cross-section: cross-sectional dimension (without coating) e.g. similar to the cord thickness of elastomer O-rings
Code Performance Index: shows characteristics of the ring (e.g. pressing load, springback)
D Groove depth: axial design dimension to which the ring is pressed from the original cross-section CSR.
F Pressing load: the mentioned guide values refer to 1mm seal length. To obtain the total load of the seal for the design of the construction, this value must be multiplied by the circumferential length of the seal.
OD Outside diameter of groove: reference dimension for internal pressure applications.
ODR min. Outside diameter of the ring: The outside diameter of the ring is freely selectable from the mentioned minimum dimension ODR min. and is at the same time the corresponding dimension to the outside diameter of the groove.
Pt coating thickness
R Radius: Design dimension that improves the support of the ring under pressure
SB Springback: maximum possible measure by which the ring can spring back elastically overall. Important value in connection with possible flange gaps.
Wmin groove width: radial design minimum dimension. The specified minimum dimension Wmin. must not be undercut.
Wt Wall thickness: sheet thickness of the ring.
Z diametric clearance between ring and groove.

The following ordering example describes a metal C-Ring for internal pressure application Typ MCI-HF in

Spring Inconel 718
Material Inconel 718
Cross section 6,35mm
Ring outer diameter ODR 525,50mm incl. coating
(suitable for groove outer diameter OD 526,00mm
normal cold-hardened
Silver coating
0.05 - 0.07 mm thick
MCI - HF7 - 7 - 6,35 x - 0525,50 - 1 S H
Metal O-Ring MCI-HF Installation space Performance
Outer diameter
Groove depth Groove width Radius Pressing load
(Guide values)
(Guide values)
Code Ø ODR min.
D +0,1
W min.
R max.
ca. N/mm
ca. mm
6,35 x 100 5,10 8,9 1,50 110 0,60
11,00 x 500 8,80 15,0 3,00 120 1,10
15,00 x 700 12,20 19,5 4,00 160 1,50

Spring material

Spring material Code Material no.
Elgiloy E 2.4711
Inconel X-750 5 2.4669
Inconel 718 7 2.4668

Ring material

Ring material Code Material no.
SS304 1 1.4306
Inconel X-750 5 2.4669
Inconel 718 7 2.4668

Other materials on request.

Heat treatment

Heat treatment Code Description
HT 1 1 work hardened
HT 2 2 age hardened
HT 3 3 Solution annealing + precipitation hardened SC
HT 4 4 Solution annealing + precipitation hardened Std
HT 5 5 Heat treatment NACE MR 0175


Coating Code max. temperature
Tin Z 200°C
PTFE P 290°C
Silver S 430°C (650°C*)
Copper C 930°C
Gold G 930°C
Nickel N 1200°C
without O

* Only valid for non-oxidizing media.
Other materials on request.

Coating thickness

Coating thickness Code
0,01 - 0,03 mm L
0,03 - 0,05 mm M
0,05 - 0,07 mm H

Other coating thicknesses on request.


Data protection information *

Mandatory fields are marked with an *.