EN 10226-3:2005

SLOVENSKI STANDARD
01-maj-2005
Cevni navoji za zveze, ki tesnijo z navoji – 3. del: Kontrola s kalibri
Pipes threads where pressure tight joint are made on the threads - Part 3: Verification by
means of limit gauges
Rohrgewinde für im Gewinde dichtende Verbindungen - Teil 3: Prüfung mit Grenzlehren
Filetage de tuyauteries pour raccordement avec étanchéité par le filetage - Partie 3:
Vérification par calibres a limites
Ta slovenski standard je istoveten z: EN 10226-3:2005
ICS:
21.040.30 Posebni navoji Special screw threads
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 10226-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2005
ICS 21.040.30
English version
Pipes threads where pressure tight joint are made on the
threads - Part 3: Verification by means of limit gauges
Filetage de tuyauteries pour raccordement avec étanchéité Rohrgewinde für im Gewinde dichtende Verbindungen - Teil
par le filetage - Partie 3: Vérification par calibres à limites 3: Prüfung mit Grenzlehren
This European Standard was approved by CEN on 22 December 2004.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 10226-3:2005: E
worldwide for CEN national Members.

Contents
page
Foreword.3
1 Scope .4
2 Normative reference .4
3 Terms and definitions .4
4 Symbols .5
5 Design of gauges.6
5.1 General.6
5.2 Taper full form threaded plug gauges (gauges No. 1 and No. 2).7
5.3 Parallel full form threaded ring gauge (gauge No. 3).11
5.4 Taper plain ring gauge (gauge No. 4) .13
5.5 Taper modified thread form check plug gauge (gauge No. 5) .14
5.6 Parallel modified thread form check ring gauge (gauge No. 6) .16
6 Use of gauges and checking of pipe threads .18
6.1 General.18
6.2 Checking of internal taper (Rc) and internal parallel (Rp) threads.19
6.3 Checking of external taper (R) threads.20
7 Gauge dimensions and manufacturing tolerances, checking of new gauges and checking
gauges for wear .21
7.1 Gauge dimensions and manufacturing tolerances.21
7.2 Checking of new gauges.28
7.3 Checking gauges for wear .31
7.4 Marking of gauges .33
Annex A (normative) Summary of gauges .34

Foreword
This document (EN 10226:2005) has been prepared by ECISS/TC 29 “Steel tubes and fittings for steel tubes”, the
secretariat of which is held by UNI.
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 August 2005, and conflicting national standards shall be withdrawn at the latest by
August 2005.
This document is based, with editorial modification, on ISO 7-2: Pipe threads where pressure-tight joints are made
on the threads – Part 2: Verification by means of limit gauges.
EN 10226 consists of the following parts, under the general title Pipe threads where pressure-tight joints are made
on the threads:
 Part 1: Taper external threads and parallel internal threads - Dimensions, tolerances and designation
 Part 2: Taper external threads and taper internal threads - Dimensions, tolerances and designation
 Part 3: Verification by means of limit gauges
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

1 Scope
This document specifies a process using limit gauges, for the validation of taper internal and external threads and
parallel internal threads on piping systems components and other products, the dimensions and tolerances of
which are detailed in EN 10226-1 and prEN 10226-2.
The gauging system described may not be suitable, without special precautions, for gauging of threads on injection
moulded plastic workpieces.
This document does not cover completely all the requirements necessary for full control of thread quality and
dimensions. Additional control of tools and equipment and visual inspection during production are required to
ensure complete compliance with EN 10226-1 and prEN 10226-2, for example the length of useful thread on
internally threaded workpieces should be checked by direct measurement.
Annex A gives a summary of the gauges included in this document, together with details of the thread elements
controlled by each gauge and gauge identification numbers.
In the event of a dispute over compliance with the requirements of EN 10226-1 and prEN 10226-2, the gauges in
this document are to be considered as decisive for the thread elements which they control on the workpiece.
2 Normative reference
The following referenced documents are indispensable for the application 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 10226-1:2004, Pipe threads where pressure-tight joints are made on the threads — Part 1: Taper external
threads and parallel internal threads — Dimensions, tolerances and designation.
prEN 10226-2:2002, Pipe threads where pressure-tight joints are made on the threads — Part 2: Taper external
threads and taper internal threads — Dimensions, tolerances and designation.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 10226-1:2004 and prEN 10226-2:2002
and the following apply.
accommodation length
distance from the face of an internally threaded workpiece to the first obstruction which the externally threaded
workpiece will encounter on assembly.
See Figure 3
4 Symbols
The symbols used and their explanations are given in Table 1.
Table 1 — Symbols
Symbol Explanation
Width of clearance groove at major diameter of parallel full form threaded ring gauges and
b
minor diameter of taper full form threaded plug gauges
Width of clearance groove at major diameter of parallel modified thread form check ring
b
gauges and at minor diameter of taper modified thread form check plug gauges
c Height of tolerance step on plug gauges
D
Major diameter of internal thread at gauge plane
D Minor diameter of internal thread at gauge plane
D Pitch diameter of internal thread at gauge plane
D
Counterbore diameter of parallel full form threaded ring gauge and taper plain ring gauge
d Major diameter of external thread at gauge plane
d
Minor diameter of external thread at gauge plane
d Pitch diameter of external thread at gauge plane
Radial distance from the pitch diameter to the truncated crest, along the centreline of the
F
thread profile
Overall length of taper full form threaded plug gauge and taper modified thread form check
l
plug gauge
l
Length from end face to the gauge plane on taper full form threaded plug gauge
l
Length of tolerance step on plug gauges
Overall length of parallel full form threaded ring gauge, parallel modified thread form check
l
ring gauge and length from gauge plane to small end of taper plain ring gauge
l Length of tolerance step on ring gauges
l Depth of counterbore on parallel full form threaded ring gauge
l
Overall length of taper full form threaded plug gauge with relief
l Width of relief on taper full form threaded plug gauge with relief
l Length from relief on taper full form threaded plug gauge with relief to large end of gauge
l Overall length of taper plain ring gauge
l Depth of counterbore on taper plain ring gauge
Distance from step on gauge Nos. 1 and 2 to face of gauge No. 6 when verifying pitch
l
diameter of new gauge Nos. 1 and 2
Distance from step on gauge No. 5 to face of gauge No. 6 when verifying pitch diameter of
l
new gauge No. 6
Distance from step on gauge Nos. 1 and 2 to face of gauge No. 6 when checking pitch
l
diameter of gauge Nos. 1 and 2 for wear
Table 1 (concluded)
Symbol Explanation
Distance from step on gauge No. 5 to face of gauge No. 3 when checking pitch diameter of
l
gauge No. 3 for wear
P Pitch
T /2 Tolerance on flank angle of full form threads
α
T /2 Tolerance on flank angle of modified form threads
α
Tolerance on pitch diameter for taper modified thread form check plug gauge and parallel
T
CP
modified thread form check ring gauge
T
Tolerance on pitch
P
T Tolerance on pitch diameter and wear allowance for taper full form threaded plug gauges
PL
Tolerance on pitch diameter and wear allowance for parallel full form threaded ring gauge and
T
R
tolerance on diameter and wear allowance for taper plain ring gauge
T Tolerance on the gauge length of an external thread
T Tolerance on position of gauge plane on an internal thread
Permissible wear on diameter of all gauges except taper modified thread form check plug
W
gauges
NOTE  The values of D, D , D , d, d and d shown in Table 2 to Table 7 are basic values and are subject to the
1 2 1 2
manufacturing tolerances specified in Clause 7.
5 Design of gauges
5.1 General
The taper full form threaded plug gauges and parallel full form threaded ring gauges (see 5.2 and 5.3) together with
the taper plain ring gauges (see 5.4) have been chosen as representing the requirements for mating components
or products within the tolerances of EN 10226-1 and prEN 10226-2.
Because of the 1:16 taper of the gauge and/or the threaded workpiece, it is possible to represent the maximum and
minimum limits of diameter by means of tolerance steps within the axial length of the gauges.
The plain ring gauges included in this document, allow a combined check of the major diameter and the length of
useful thread of externally threaded workpieces.
The taper modified thread form check plug gauge (see 5.5) and parallel modified thread form check ring gauge
(see 5.6) for checking the manufacturing tolerances and wear allowances for the parallel full form threaded ring
gauges and taper full form threaded plug gauges respectively, are made to a modified thread form.
Some dimensions given in this document are more precise than the equivalent dimensions given in
EN 10226-1 and prEN 10226-2. This greater precision is only intended to assist the gauge manufacturing process
and is of no practical significance when using the gauges.
NOTE The expression "full form" has been used to describe those threaded plug and ring gauges which may be full form or
al
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