🔩 Textile conveyor belts — full thickness tensile strength (greatest force divided by the width of the test piece, N/mm), elongation at break and elongation at the reference force (1/10 of the nominal tensile strength × width of the test piece); test pieces of type A, B, C and D, gauge length 100 mm, extension at (100 ± 10) mm/min; PN-EN ISO 283

Materials and NDT PN-EN ISO 283

Overview

WHAT THE STANDARD COVERS. According to clause 1 of ISO 283:2023 the standard specifies a test method for the determination of the full thickness tensile strength in the longitudinal direction and of the elongation at the reference force and at break of conveyor belts having a textile carcass. The method can also be used to determine the tensile strength in the transverse direction and the elongation at break in that direction — when the purchaser requests the manufacturer to state these values. The standard does not apply to light conveyor belts described in ISO 21183-1. It is a test method only: the table of contents has no clause with requirements — minimum values of strength and elongation are given in product standards. According to the iTeh catalogue, ISO 283:2023 is referred to by, among others, EN ISO 14890:2026 (textile conveyor belts for general use), EN ISO 22721:2023 (belts for underground mining) and EN ISO 1120:2025 (strength of mechanical fastenings) — we have not read these standards. "Scope" field of the PKN card for PN-EN ISO 283:2023-10 (English version, description in Polish): "This document specifies a method for the determination of the tensile strength in the longitudinal direction, the elongation at break and the elongation at the reference load of full thickness conveyor belts having a textile carcass."

ACCORDING TO THE TEXT OF ISO 283:2023 — EDITION, TERMS, APPARATUS (forewords, clauses 1–5). The standard was prepared by ISO/TC 41 (Pulleys and belts), Subcommittee SC 3 (Conveyor belts), in collaboration with CEN/TC 188 (Conveyor belts; secretariat SNV). The fifth edition (2023-03) replaced the fourth (ISO 283:2015) after a technical revision; changes according to the foreword: a requirement for a conditioning period before sampling (assigned in the foreword to 6.1, in the text read the sentence stands in 6.2), clarification of the point at which the width of the test piece is measured (6.3), a requirement to reduce the covers in the grip areas (6.3) and deletion of the humidity requirement (6.5). CEN approved EN ISO 283:2023 on 1 March 2023 without any modification of the ISO text; national implementation and withdrawal of conflicting national standards — at the latest by October 2023; it superseded EN ISO 283:2015. Normative references: ISO 7500-1 (verification of the force-measuring system of testing machines) and ISO 18573 (test atmospheres and conditioning periods for conveyor belts). Terms (clause 3): tensile strength — the greatest force measured during the test divided by the width of the test piece, in N/mm; nominal tensile strength — the specified minimum value of the belt tensile strength, in N/mm; reference force (reference load, in the Polish title "zadane obciążenie") — one tenth of the nominal tensile strength in the longitudinal direction multiplied by the width of the test piece in millimetres; example from the standard: nominal tensile strength 1600 N/mm, one tenth — 160 N/mm, reference force for a 25 mm test piece — 25 mm × 160 N/mm = 4000 N; elongation at break — elongation at the greatest force; elongation at the reference force — elongation in the longitudinal direction at the reference force; both elongations as the percentage increase in the distance between two reference points. Principle (clause 4): a test piece cut from the full thickness of the belt is extended under specified conditions in a tensile testing machine until it breaks. Apparatus (clause 5): a machine of CRE or CRT type, calibrated to Grade 1 according to ISO 7500-1, extending the test piece without interruption at a constant rate of (100 ± 10) mm/min; a device, e.g. an extensometer, with a measuring length of at least 100 mm and an accuracy of 0.1 mm or better, measuring the elongation of the length marked on the test piece — preferably one that records a trace throughout the test; grips that prevent the test piece from slipping — grips with transverse serrations are recommended (Figure 1); a die cutter or power saw — the sides of the test piece shall be perpendicular to its surfaces (Figure 2 — die profiles).

TEST PIECES (6.1–6.2 and Figures 3–5). Shape and dimensions according to Figures 3–6. Reading from the figures (dimensions in millimetres; L — length of both grips; reference lines 100 mm apart): type A — arc radius 1000, end width 35, width at the centre 25 (+1/−2), overall length (220 ± 10) + L; type B — radius 560, ends 100, centre 25 (+1/−2), length (415 ± 10) + L; type C — radius 350, ends 63, centre 25 (+1/−2), length (240 ± 10) + L. Type D (Figure 6) — the shape is drawn on the belt or sample, and from each edge cuts are made with a power saw at five places up to the drawn lines; the standard recommends limiting it to belts with a tensile strength greater than 2000 N/mm. Sampling (6.2): the specimen is taken at least 24 h after manufacture of the belt, and any shorter period has to be recorded; test pieces are cut parallel or at right angles to the axis of the belt, not less than 50 mm from its edge; from a sample cut from the belt — not less than 12 mm from its edge (measured from the longitudinal edge of the test piece); cut or sawn sides perpendicular to the surface; no test piece may contain a ply joint. The rest of clause 6 (6.3 preparation, 6.4 number of test pieces, 6.5 conditioning), clause 7 (procedure), 8 (calculation: 8.1 tensile strength, 8.2.1 elongation at break, 8.2.2 elongation at the reference force) and 9 (test report) are outside the part read — we know only their titles from the table of contents.

STATUS (PKN cards as of 09.11.2026). The card for PN-EN ISO 283:2023-10 (English version) has no withdrawal label: published 03-10-2023, 22 pages, KT 186 for Rubber and Rubber Products, "Implements: EN ISO 283:2023 [IDT], ISO 283:2023 [IDT]", "Replaces: PN-EN ISO 283:2016-01 - English version", ICS 53.040.20. The card for PN-EN ISO 283:2016-01 (English version; implemented EN ISO 283:2015 and ISO 283:2015) — withdrawn 03-10-2023, replaced by PN-EN ISO 283:2023-10; it had itself replaced PN-EN ISO 283:2008 (Polish version). In the PKN search results (query "PN-EN ISO 283", 09.11.2026) the cards of this standard are PN-EN ISO 283-1:2002 (Polish and English), PN-EN ISO 283:2007 (English), PN-EN ISO 283:2008 (Polish), PN-EN ISO 283:2016-01 and PN-EN ISO 283:2023-10 (English) — there is no Polish version of the 2023 edition. iTeh catalogue (read 09.11.2026): ISO 283:2023 — published 30.03.2023, stage "6060 – International Standard published"; ISO 283:2015 — withdrawn (stage 9599); EN ISO 283:2023 — published 11.04.2023, CEN/TC 188, stage 6060; the relations on the cards show no newer edition or draft.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, read 09.11.2026; "Laboratories" tab on labcoda.pl, 09.11.2026). The notation "ISO 283" appears in 4 records at 4 Polish laboratories — AB 005, AB 169, AB 710 and AB 1552, 1 record each, always in the form "PN-EN ISO 283:2023-10", i.e. the current edition. Outside Poland the notation "ČSN EN ISO 283" appears in 1 record of the Czech laboratory 1004 (together with the Czech standard ČSN 26 0370). Not included in the set are 26 records in which the string "283" belongs to another document: "PN-EN 283:1999" — according to the PKN card the standard "Swap bodies — Testing" (implements EN 283:1991), not a standard on belts — at AB 053 (10 records, rail vehicle bodies) and AB 1627 (1 record, load securing elements on vehicles of categories N and O); "ČSN EN 283" at the Czech 1085 (2 records, containers); "ASTM E283/E283M" at AB 023 (8) and AB 1054 (1); 4 Czech records with the number 283 in an article page number, a procedure designation and the number of a Czech regulation. The "Laboratories" tab ("PN-EN ISO 283", matching from the start of the notation) shows 5 laboratories — these 4 Polish ones and the Czech 1004 — with the same number of items as the copy (5) (tab query on labcoda.pl, 09.11.2026). We have not compared the current PCA scope documents of these laboratories with the copy.

WHAT THE LABORATORIES TEST (copy of the database, complete items — 4). AB 005 — conveyor belts and other laminated materials up to 40 mm thick: tensile strength, maximum load 300 kN. AB 169 — conveyor belts with a textile carcass and drive belts: tensile strength, elongation at break, elongation at the reference load; force up to 100 kN, elongation up to 250 mm. AB 710 — conveyor belts with a textile carcass: tensile strength, elongation at 10 % of the nominal strength, maximum force 100 kN, test pieces of type A, B and C. AB 1552 — conveyor belts: tensile strength, elongation at break, elongation at the reference load; force (1–1000) kN, displacement (0–98) mm. Czech item 1004 — conveyor belts with textile plies, determination of tensile properties. Drive belts (AB 169) and other laminated materials (AB 005) are not mentioned in clause 1 of the standard.

WHERE AN APPARENTLY CORRECT RESULT IS EASY TO GET. Sampling: a test piece cut earlier than 24 h after manufacture of the belt without recording that time, closer than 50 mm to the edge of the belt, with a ply joint or with sides not perpendicular to the surface does not meet 6.2 — the result looks like an ordinary measurement but concerns a different test piece. Measurement: the reference force is calculated from the NOMINAL tensile strength (the value specified for the belt), not from the measured greatest force — recalculating it from the result of the same test piece gives a different force and a different elongation; the elongation at the reference force applies to the longitudinal direction only. Elongation is measured by a device on the length marked on the test piece (at least 100 mm, 0.1 mm) — the displacement of the machine grips is not this quantity. The rate shall be constant and uninterrupted, (100 ± 10) mm/min. Calculation: the tensile strength is given in N/mm — force per unit width of the test piece, not stress per cross-section (MPa); for a 1600 N/mm belt and a 25 mm test piece the reference force is 4000 N (example in 3.3), and the force corresponding to the nominal tensile strength is 40 000 N (1600 N/mm × 25 mm, calculation from definition 3.1) — the machine and grips have to carry the force that breaks the test piece. Edition: ISO 283:1990 (second edition, "Specifications and method of test") also contained requirements (e.g. elongation at the reference load at most 4 %, at break at least 10 %), sampling at least 5 days after manufacture and conditioning for 3 days at (23 ± 2) °C and (50 ± 5) % relative humidity — the 2023 edition is a method only, sampling takes place after 24 h, and the humidity requirement in 6.5 was deleted; carrying numbers over from the old edition gives an assessment according to a text that is no longer valid. The result concerns a belt without a ply joint; the strength of mechanical fastenings is tested by another standard (according to the iTeh catalogue EN ISO 1120:2025 — not read).

WHAT WE DO NOT GIVE. Parts read: the iTeh sample of SIST EN ISO 283:2023 (title page, European foreword, ISO foreword, table of contents, clauses 1–3.3) and the iTeh sample of ISO 283:2023 (English and French versions: clauses 1–6.2 with Figures 1–5). We do not give the content of 6.3–9: the point at which the width is measured, the reduction of the covers in the grip areas, the number of test pieces, the conditioning atmosphere and period (ISO 18573 from the normative references — not read), the distance between the grips, the manner of reading, the treatment of a test piece breaking outside the reference lines or slipping out of the grips, the formulae and rounding of the result, or the contents of the test report — we have not read these clauses. We do not give the dimensions of Figure 6 (type D) in the 2023 edition or the dimensions of Figures 1 and 2. A description of the procedure by a manufacturer of tensile testing machines (page on ISO 283, read 09.11.2026) agrees with the clauses read (rate, 100 mm gauge length, reference force); we do not carry further numbers over from it, because it is not the text of the standard. Referenced standards (PKN cards, 09.11.2026): PN-EN ISO 7500-1:2018-05 (Polish version, published 23-11-2022, implements EN ISO 7500-1:2018 and ISO 7500-1:2018) — no withdrawal label; ISO 18573 — no card in the PKN search (query "ISO 18573"), status not established; ISO 21183-1 — the search shows the card for PN-EN ISO 21183-1:2006 (English version), whose status we have not checked. We have not read the product standards (ISO 14890, ISO 22721, ISO 1120).

Method principle

A test piece cut from the full thickness of the belt (type A, B, C or D) is extended in a CRE or CRT machine of Grade 1 according to ISO 7500-1 at a constant rate of (100 ± 10) mm/min until it breaks; the tensile strength is the greatest force divided by the width of the test piece (N/mm), the elongation at break and at the reference force (1/10 of the nominal tensile strength × width of the test piece, longitudinal direction only) is the increase of the 100 mm length between the lines on the test piece in per cent (ISO 283:2023, clauses 3–6.2; clauses 6.3–9 — only titles in the part read).

Applications

• Conveyor belts with a textile carcass — strength and elongations in the longitudinal direction, in the transverse direction at the purchaser's request (ISO 283:2023, clause 1)
• Method referred to in product standards for textile conveyor belts — according to the iTeh catalogue, among others EN ISO 14890:2026 and EN ISO 22721:2023
• Does not apply to light conveyor belts described in ISO 21183-1
• In accreditation scopes: 4 Polish laboratories — tensile strength, elongation at break and at the reference load, forces up to 100, 300 and 1000 kN

Key parameters

Standard

Standard number

PN-EN ISO 283:2023-10 (English version; implements EN ISO 283:2023 and ISO 283:2023 [IDT])

Title (PL)

Taśmy przenośnikowe z rdzeniem tekstylnym — Wytrzymałość na rozciąganie taśmy o całkowitej grubości, wydłużenie przy zerwaniu oraz wydłużenie przy zadanym obciążeniu — Metoda badania

Title (EN)

Textile conveyor belts — Full thickness tensile strength, elongation at break and elongation at the reference load — Test method

Step-by-step procedure

1. Sampling

   At least 24 h after manufacture of the belt (record a shorter period); parallel or at right angles to the axis, ≥ 50 mm from the belt edge, ≥ 12 mm from the edge of the cut sample; no ply joint; sides perpendicular to the surface (6.2).

2. Shape of the test piece

   Type A, B, C or D according to Figures 3–6; width at the centre 25 (+1/−2) mm, two reference lines 100 mm apart; type D (saw cuts at five places from each edge) — recommended for belts with a tensile strength > 2000 N/mm (6.1–6.2).

3. Preparation and conditioning

   According to 6.3–6.5 (width measurement, reduction of covers in the grip areas, number of test pieces, conditioning; the normative references include ISO 18573 — test atmospheres and conditioning periods) — we have not read these subclauses.

4. Extension

   Constant rate of (100 ± 10) mm/min without interruption until break; in the longitudinal direction, reading of the elongation at the reference force (1/10 of the nominal tensile strength × width of the test piece); greatest force and elongation at it (clauses 3–5; procedure according to clause 7 — not read).

5. Result

   Tensile strength in N/mm (greatest force / width), elongations in % of the length between the reference lines (clause 3; formulae and rounding — clause 8, not read). PN-EN ISO 283:2023-10 — current (PKN card as of 09.11.2026; English version).

Required equipment and apparatus

Health and safety (OHS)

• Break of a belt test piece at a force of tens of kN — guards around the extension zone, nobody in line with the grips
• Cutting thick belts with plies with a power saw and die cutter — tool guards, hand protection
• TECHNICAL NOTE: the reference force is calculated from the nominal tensile strength, not from the measured one; the standard gives no requirements for belts — only the method

Frequently asked questions