SIST EN 2755:2022
(Main)Aerospace series - Bearing, spherical, plain in corrosion resisting steel with self-lubricating liner - Elevated load at ambient temperature - Technical specification
Aerospace series - Bearing, spherical, plain in corrosion resisting steel with self-lubricating liner - Elevated load at ambient temperature - Technical specification
This European standard specifies the required characteristics, inspection and test methods, qualification and acceptance conditions for spherical plain bearing in corrosion resisting steel, with self-lubricating liner, for elevated loads at ambient temperature intended for use in fixed or moving parts of the aircraft structure and control mechanisms.
This standard applies whenever referenced.
Luft- und Raumfahrt - Gelenklager, aus korrosionsbeständigem Stahl mit selbstschmierender Beschichtung - Reihe hohe Belastungen bei Raumtemperatur - Technische Lieferbedingungen
Dieses Dokument legt die Anforderungen, Überprüfungen und Prüfverfahren, Qualifikations- und Annahmebedingungen für ein Gelenklager aus korrosionsbeständigem Stahl mit selbstschmierender Beschichtung für hohe Belastungen bei Raumtemperatur zur Verwendung in starren oder beweglichen Flugwerkteilen und deren Betätigungs¬einrichtungen fest.
Dieses Dokument ist anzuwenden, wenn auf es verwiesen wird.
Série aérospatiale - Rotule, en acier résistant à la corrosion à garniture autolubrifiante - Série à charge élevée à température ambiante - Spécification technique
Le présent document spécifie les caractéristiques requises, les méthodes de contrôle et d'essai, les conditions de qualification et de réception d’une rotule en acier résistant à la corrosion, à garniture autolubrifiante, conçues pour supporter des charges élevées à température ambiante, destinées à être utilisées dans les parties fixes ou mobiles de la structure et des dispositifs de commande de l’aéronef.
Le présent document s'applique chaque fois qu'il est cité en référence.
Aeronavtika - Kroglasti drsni ležaj iz korozijsko odpornega jekla s samomazalno oblogo - Serija za večje obremenitve pri okoljski temperaturi - Tehnična specifikacija
Ta evropski standard določa zahtevane značilnosti, preglede in preskusne metode ter kvalifikacijo in pogoje sprejemljivosti za kroglaste drsne ležaje iz korozijsko odpornega jekla s samomazalno oblogo za večje obremenitve pri okoljski temperaturi, ki so namenjeni za uporabo v fiksnih ali premikajočih se delih ogrodja letala in nadzornih mehanizmih.
Ta standard se uporablja, kadar je naveden.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 2755:2022
01-januar-2022
Nadomešča:
SIST EN 2755:2009
Aeronavtika - Kroglasti drsni ležaj iz korozijsko odpornega jekla s samomazalno
oblogo - Serija za večje obremenitve pri okoljski temperaturi - Tehnična
specifikacija
Aerospace series - Bearing, spherical, plain in corrosion resisting steel with self-
lubricating liner - Elevated load at ambient temperature - Technical specification
Luft- und Raumfahrt - Gelenklager, aus korrosionsbeständigem Stahl mit
selbstschmierender Beschichtung - Reihe hohe Belastungen bei Raumtemperatur -
Technische Lieferbedingungen
Série aérospatiale - Rotule, en acier résistant à la corrosion à garniture autolubrifiante -
Série à charge élevée à température ambiante - Spécification technique
Ta slovenski standard je istoveten z: EN 2755:2021
ICS:
49.035 Sestavni deli za letalsko in Components for aerospace
vesoljsko gradnjo construction
SIST EN 2755:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 2755:2022
---------------------- Page: 2 ----------------------
SIST EN 2755:2022
EN 2755
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 49.035 Supersedes EN 2755:2009
English Version
Aerospace series - Bearing, spherical, plain in corrosion
resisting steel with self-lubricating liner - Elevated load at
ambient temperature - Technical specification
Série aérospatiale - Rotule, en acier résistant à la Luft- und Raumfahrt - Gelenklager, aus
corrosion à garniture autolubrifiante - Série à charge korrosionsbeständigem Stahl mit selbstschmierender
élevée à température ambiante - Spécification Beschichtung - Reihe hohe Belastungen bei
technique Raumtemperatur - Technische Lieferbedingungen
This European Standard was approved by CEN on 12 July 2020.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 2755:2021 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Requirements characteristics, inspection and test method . 7
5 Quality assurance. 20
5.1 Production qualification . 20
5.2 Acceptance conditions . 20
5.2.1 Inspection and tests to be carried out by the manufacturer . 20
5.2.2 Purchaser’s (user’s) quality control . 20
6 Packaging . 21
7 Certificate of compliance . 21
8 Quality management systems. 28
Annex A (normative) Verification of permissible and ultimate static loads . 29
A.1 Permissible radial static load (C ) . 29
s
A.1.1 Principle . 29
A.1.2 Method . 29
A.2 Ultimate radial static load . 29
A.2.1 Principle . 29
A.2.2 Method . 29
A.3 Permissible axial static load (C ) . 30
a
A.3.1 Principle . 30
A.3.2 Method . 30
A.4 Ultimate axial static load . 30
A.4.1 General . 30
A.4.2 Principle . 30
A.4.3 Method . 30
Annex B (normative) Verification of dynamic radial load (C ) . 33
25
B.1 Principle . 33
B.2 Method . 33
B.2.1 Testing at ambient temperature . 33
B.2.2 Testing at low temperature . 33
B.2.3 Testing at elevated temperature . 33
2
---------------------- Page: 4 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
B.2.4 Test at ambient temperature after immersion . 34
Annex C (normative) Fluids — Essential characteristics . 35
C.1 Fuel for turbine aero engine . 35
C.2 Fluids for de-icing circuit . 35
C.3 Hydraulic fluids . 35
C.3.1 Mineral fluid for hydraulic transmission . 35
C.3.2 Phosphate of ester hydraulic fluid . 36
C.4 De-icing and anti-icing fluids . 36
Annex D (normative) Measurement of the peel strength of the liner . 37
D.1 Principle . 37
D.2 Method . 37
Annex E (normative) Simplified qualification procedure . 39
E.1 Rules for application . 39
E.1.1 General . 39
E.2 Choice of references . 39
E.3 Rules for qualification . 40
E.4 Plain bearing distribution . 41
Bibliography . 43
3
---------------------- Page: 5 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
European foreword
This document (EN 2755:2021) has been prepared by the Aerospace and Defence Industries
Association of Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
ASD-ASD, prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2022, and conflicting national standards shall be
withdrawn at the latest by May 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 2755:2009.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
4
---------------------- Page: 6 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
1 Scope
This document specifies the required characteristics, inspection and test methods, qualification and
acceptance conditions for a spherical plain bearing in corrosion resisting steel, with self-lubricating
liner, for elevated loads at ambient temperature intended for use in fixed or moving parts of the aircraft
structure and control mechanisms.
This document applies whenever referenced.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 2064, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
liner — Technical specification
EN 2584, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
liner — Narrow series — Elevated loads at ambient temperature — Dimensions and loads
EN 2585, Aerospace series — Bearing, spherical plain in corrosion resisting steel with self-lubricating
liner — Wide series — Elevated load at ambient temperature — Dimensions and loads
EN 3048, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
liner — Light series — Elevated load at ambient temperature — Dimensions and loads
EN 4037, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
1
liner, reduced starting torque — Light series — Dimensions and loads
EN 4038, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
1
liner reduced starting torque — Normal narrow series — Dimensions and loads
EN 4039, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
1
liner reduced starting torque — Normal wide series — Dimensions and loads
EN 4040, Aerospace series — Bearings, spherical plain in corrosion resisting steel with self-lubricating
liner with wide inner ring — Elevated loads at ambient temperature — Dimensions and loads
EN 4613, Aerospace series — Spherical plain bearings in corrosion resisting steel with self-lubricating
liner, narrow series — Dimensions and loads — Inch series
EN 4614, Aerospace series — Spherical plain bearings in corrosion resisting steel with self-lubricating
liner, wide series — Dimensions and loads — Inch series
EN 6096, Aerospace series — Bearing, spherical plain with self-lubricating liner, extra wide inner ring in
corrosion resisting steel — Dimensions and loads — Inch series
EN 9100, Quality Management Systems — Requirements for Aviation, Space and Defence Organizations
EN 10204, Metallic products — Types of inspection documents
1
Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence
Industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).
5
---------------------- Page: 7 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
ISO 11078, Aircraft — De-icing/anti-icing fluids, ISO types II, III and IV
TR 4475, Aerospace series — Bearings and mechanical transmissions for airframe applications —
2
Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in TR 4475 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org/
3.1
spherical plain bearings with self-lubricating liner
spherical plain bearings consisting of two concentric rings between which is interposed a
self-lubricating liner which is bonded or moulded onto the spherical inner surface or the spherical outer
surface
3.2
Surface discontinuities
3.2.1
score, scratch
open surface defect
3.2.2
lap
surface defect where particles of metal or sharp edges are folded over and then rolled or forged into the
surface
3.2.3
seam
unwelded fold which appears as an open defect in the material
3.3
starting torque without load
torque required to start the rotation of the inner with the outer ring held stationary
2
Published as ASD-STAN Technical Report at the date of publication of this standard by AeroSpace and Defence
Industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).
6
---------------------- Page: 8 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
3.4
Permissible static loads
3.4.1
radial
C
s
static load corresponding to a permissible unit pressure multiplied by the effective projected area in the
radial direction, the inner ring being able to take any position within the limits of the tilting angle
indicated in the product standard
3.4.2
axial
C
a
static load corresponding to a permissible unit pressure multiplied by the effective projected area in the
axial direction
3.5
dynamic radial
C
25
load which may be withstood by a bearing submitted to an oscillatory movement for a defined number
and frequency of oscillation cycles without the dimensional or other characteristics deviating from the
values permitted by the technical specification of the product
Note 1 to entry: One oscillating cycle includes an angular displacement of the inner ring in relation to the outer
ring from 0° to 25° then from 25° to −25° and finally from −25° to 0°.
3.6
adhesion of the liner
area where the adhesive bond is broken, or non-existent, leaving a smooth and clean interface on the
metallic surface
3.7
production batch
batch of products composed of elements which may come from more than one element batch but which
are assembled in the same production series
4 Requirements characteristics, inspection and test method
See Table 1.
Table 1 (1 of 4)
a b
Clause Characteristic Requirements Inspection and test method
Q A
4.1 Material In accordance with the Chemical analysis or X X
product standard or design certificate of compliance
documentation. according to EN 10204,
issued by semi-finished
product manufacturer.
7
---------------------- Page: 9 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.2 Dimensions, In accordance with the Suitable measuring X X
tolerances product standard or design instruments.
documentation.
Measurement of bore and
outer diameter:
— Rings with a width of
≤ 10 mm: in the centre
plane;
— Rings with a width of
> 10 mm: in two planes
parallel to the outer faces
and at a distance of these
faces of twice the
maximum value of the
ring chamfer. The
minimum and maximum
diameters shall be
determined in each
measuring plane.
Measurement of ring width:
— The width of each ring
(distance between the
two faces) shall be
verified at a minimum of
four points.
4.3 Masses In accordance with the Suitable methods. X
product standard or design
documentation.
4.4 Marking In accordance with the Visual examination. X X
product standard or design
documentation.
It shall be legible and shall
not adversely affect the
material or the functioning of
the bearing.
4.5 Surface The bearings shall be visually
free of surface discontinuities
appearance
(examples: scratch, score,
seam, lap) liable to have an
adverse effect on their
characteristics and
endurance.
The liner shall not contain
contaminant products and
shall not show broken or
voided areas.
Lubrication shall not be
permitted.
8
---------------------- Page: 10 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.5.1 Assembled Visual inspection using X X
bearings suitable methods.
4.5.2 Unassembled Magnetic or dye penetrant X X
rings inspection.
4.6 Hardness In accordance with the Suitable processes and X X
product standard or design measuring instruments.
documentation.
4.7 Surface In accordance with the Suitable processes and X X
roughness product standard or design measuring instruments.
documentation.
4.8 Surface In accordance with the Visual inspection. X X
treatment product standard or design
As per surface treatment
documentation.
standard.
Table 1 (2 of 4)
a b
Clause Characteristic Requirements Inspection and test method
Q A
4.9 Behaviour in Bearings shall be able to Manual inspection. X X
rotation and move freely within the
tilt angular limits specified in the
product standards or design
documentation.
4.10 Starting torque
without load
4.10. At ambient In accordance with the Suitable processes and X X
1 temperature product standard or design measuring instruments:
documentation.
— measurement of the
starting torque shall be
preceded by some
rotations and a few
turning movements by
hand;
— measure the torque,
apply gradually to the
inner ring, in both
directions, with the outer
ring held stationary. Read
off the maximum value
required to start up the
inner ring.
4.10. At low Starting torque ≤ twice those Subject the bearing, during X
2 temperature listed in the product standard 4 h at the minimum
or design documentation. temperature ±5 °C.
Immediately after, measure
the torque following 4.10.1.
9
---------------------- Page: 11 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.10. After limit In accordance with Tables 2 Subject the bearing, during X
3 temperatures and 3. 1 h at the minimum
temperature ±5 °C, then 1 h at
the maximum temperature
±2 °C.
Repeat successively × 10
this test.
4 h after these tests, measure
the torque, at ambient
temperature, following
4.10.1.
4.11 Conformity of For fabric type liners no Clad the bearing in plastic X
spherical difference between material identical to that used
surface measurements obtained on for metallurgical mounts.
spherical surfaces shall
Section the bearing on a
exceed 0,08 mm.
diameter and normal to the
race side face.
Grind and polish the exposed
surface.
Measure distance ‘t’, checked
at a minimum of five points
uniformly spaced around the
spherical diameter with the
aid of, for example, an optical
dial indicator (see Figure 1).
For moulded liners: Clad the bearing in plastic X
material identical to that used
— the maximum liner
for metallurgical mounts.
thickness shall occur
between C/10 position; Section the bearing on a
diameter and normal to the
— the minimum liner
race side face.
thickness shall be
Grind and polish the exposed
0,20 mm.
surface.
Table 1 (3 of 4)
a b
Clause Characteristic Requirements Inspection and test method
Q A
Measure distance ‘t’, checked
at a minimum of five points
uniformly spaced around the
spherical diameter with the
aid of, for example, an optical
dial indicator (see Figure 1).
The points shall include the
midpoint and the C/10
positions.
10
---------------------- Page: 12 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.12 Permissible In accordance with the See Annex A. X
static loads: product standard or design
documentation.
— radial: C
s
No maximum total deflection
greater than those listed in
— axial: C
a
Table 4 and Table 5 under
permissible static loads (C ).
s
After removing the loads, no
permanent deformations
greater than those listed in
Table 4 and Table 5.
4.13 Ultimate static After removing the loads, See Annex A. X
loads: there shall be no cracks, no
push out of the inner ring or
— radial
deterioration of the bearing.
— axial
4.14 Dynamic radial In accordance with the See Annex B. X
loads C : product standard or design
25
documentation.
— at ambient
After the removal of the
temperatur
loads:
e
— no metal-to-metal contact
— at low
between inner and outer
temperatur
ring;
e
— the liner wear shall not
— at elevated
exceed the values listed
temperatur
in Table 6;
e
— the peel strength and the
— at extended
bond integrity shall
cycles. conform with 4.16 and
Type C or D.
4.17.
At the end of the test, the Suitable processes and
starting torque under radial measuring instruments.
load shall be measured and
shall conform with values
listed in Tables 7 and 8.
11
---------------------- Page: 13 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.15 Liner At the end of this test, see Check one bearing per fluid: X
compatibility 4.14.
— put the inner ring
with the fluids
perpendicularly to the
outer ring;
— the bearing shall be
immersed for 24 h in the
fluids stated in Annex C at
the following
temperatures:
— (45 ± 3) °C for those
defined in C.1 and
C.2;
— (70 ± 3) °C for those
defined in C.3;
— ambient temperature
for those defined in
C.4.
Table 1 (4 of 4)
a b
Clause Characteristic Requirements Inspection and test method
Q A
Within ½ h after this test, X
proceed to the test defined in
B.2.4.
4.16 Peel strength These requirements and this See Annex D. X X
of the liner test apply only in the case
For acceptance, this test shall
where the manufacturer has
be carried out immediately
established whether the liner
after assembling and curing.
is peelable or non-peelable.
It shall present a mean
peeling resistance > 0,35 N
for each millimetre of the
outer ring reduced by 2 mm
to eliminate the effects of
edges and chamfers.
Mean peeling resistance is
determined using at least
75 % of the values on the
recording curve.
12
---------------------- Page: 14 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
4.17 Bond integrity For peelable liner, the liner: After the peel strength test, X
of the liner evaluate the location and size
— shall not contain any
of any voids.
contamination
substances;
— shall adhere tightly to the
outer ring over at least
90 % of the contact area.
No void shall be allowed
which cannot be
described within a circle
of diameter equal to:
— 25 % of outer ring width;
— 6 mm
whichever is smaller.
For non-peelable liners, a Destructively examine the X X
sectioned bearing shall be liner by chipping, scraping,
examined for bond integrity. abrasion, or other
appropriate means to
The liner:
determine the bond integrity.
— shall adhere tightly to the
outer ring over at least
90 % of the contact area.
No void shall be allowed
which cannot be
circumscribed within a
circle of diameter equal
to:
— 25 % of outer ring width;
— 6 mm
whichever is smaller.
a
Q: Qualification test.
b
A: Acceptance test.
13
---------------------- Page: 15 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
Table 2 — Starting torques without load for bearings, metric series
Metric series
Diameter
Starting torque without load
Code Nom. EN 2584 EN 4038 EN 2585 EN 4039 EN 3048 EN 4037 EN 4040
code N code L
mm Nm Nm Nm Nm Nm Nm Nm
05 5
0,08 to 0,5
0,005 to
06 6 0,005 to 0,01 to 0,2
0,08 to 0,5 0,06
0,06
0,12 to
0,006 to
08 8 0,80
0,08
0,02 to 0,4
10 10
0,008 to
0,008 to
0,1
12 12
0,008 to
0,12 to 0,8
0,1
0,12 to 0,8
0,1
15 15
0,12 to 0,8
0,01 to 0,01 to
17 17
0,12 0,12
20 20
22 22
0,015 to
0,25 to 1
0,015 to 0,015 to
0,25
25 25 0,25 to 1 0,25 to 1
0,25 0,25
30 30
0,02 to 0,4 0,4 to 2 0,02 to 0,4 0,4 to 2 0,02 to 0,4
35 35
0,4 to 2
0,025 to 0,025 to
40 40
0,5 0,5
0,03 to 0,6
45 45
0,6 to 2,7 0,6 to 2,7
0,6 to 2,7 0,03 to 0,6 0,03 to 0,6
50 50
55 55
14
---------------------- Page: 16 ----------------------
SIST EN 2755:2022
EN 2755:2021 (E)
Table 3 — Starting torques without load for bearings, inch series
Inch series
Diameter
Starting torque without load
EN 4613 EN 4614 EN 6096
Code Nominal normal reduced normal reduced normal reduced
code N code R code N code R code N code R
mm Nm Nm Nm Nm Nm Nm
03 4,826 0,06 to 0,34 0,06 to 0,56 0,06 to 0,34
04 6,35
0,0 to 0,11 0 to 0,11 0 to 0,11
05 7,937
06 9,525 0,11 to 0,56
07 11,113
0,11 to 0,56 0,11 to 0,56 0,03 to 0,15
08 12,700
09 14,288 0,03 to 0,15 0,03 to 0,15
10 15,875
0,11 to 0,56 0,03 to 0,15
12 19,050
14 22,225
0,23 to 0,90 0,04 to 0,25 0,23 to 0,90 0,04 to 0,25 0,23 to 0,90 0,04 to 0,25
16 25,400
20 31,750 0,05 to 0,32
24 38,100 0,23 to 1,50
0,23 to 1,50 0,05 to 0,32 0,23 to 1,50 0,05 to 0,32 0,11
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.