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ISO 1421
Tensile Strength and Elongation of Rubber- or Plastics-Coated Fabrics

Universal Grip ISO 1421 vise grip jaw faces for coated fabric tensile tests

Downloads: ISO 1421 Vise Grip Jaw Faces for Coated Fabric Tensile Tests – Universal Grip Data Sheet (PDF)

Written by Chris Thomas, Universal Grip Company · Reviewed by Frank Bertini · Updated October 24, 2026

ISO 1421 is the tensile test for rubber- or plastics-coated fabrics: PVC tarpaulins and architectural membranes, polyurethane-coated nylon for inflatables and protective clothing, rubber-coated conveyor and technical textiles. It gives two methods. Method 1, the strip test, pulls a 50 mm wide strip held across its full width at 100 mm/min and reports both the maximum force and the elongation; Method 2, the grab test, clamps only the central 25 mm of a 100 mm wide piece and reports maximum force only. The results are reported in newtons for the warp (longitudinal) and weft (transverse) directions separately, and they are the numbers on nearly every coated-fabric specification sheet in Europe and Asia.

This guide covers the current edition, ISO 1421:2016, and what changed from 1998; the complete parameter set for both methods with their tolerances (which most equipment pages get wrong); the 2/5/10 N pre-tension table and slack mounting; the jaw-separation options; the slip and jaw-break rejection rules; the three bases for elongation; rounding and reporting; why strip and grab results are not comparable; a worked example; common errors; a numeric comparison with ISO 13934-1 and -2 for uncoated fabrics and with ASTM D751; and the jaw faces, grips and machines Universal Grip supplies for the test.

In this guide: What ISO 1421 Measures and Why Coated Fabrics Have Their Own Standard · Editions: 1977, 1998 and ISO 1421:2016 · Method 1: The Strip Test · Method 2: The Grab Test · Machine, Clamps, Conditioning and Time After Manufacture · Rejection Rules: Slippage and Jaw Breaks · Elongation: Three Gauge Bases · Step-by-Step Procedure (Strip Test) · Worked Example · Common Errors and How Much They Matter · ISO 1421 vs ISO 13934-1, ISO 13934-2 and ASTM D751 · Equipment: Jaw Faces, Grips and Machines from Universal Grip · FAQ

What ISO 1421 Measures and Why Coated Fabrics Have Their Own Standard

A coated fabric is a woven, knitted or nonwoven textile with a continuous rubber or plastic coating on one or both sides. The coating changes how the material behaves in a tensile test: it is slippery or tacky in the jaws, it stops the yarns sliding against each other, and it is usually tested as a finished product rather than as a textile. ISO 13934-1, the uncoated-fabric strip test, says explicitly that it is usually not applicable to coated fabrics, and ISO 1421 is the method written for them. Its two methods report:

  • Maximum force (N): the highest force reached while extending the test piece to break, per 50 mm strip (Method 1) or per 100 mm grab piece (Method 2). ISO 1421 reports force, not stress, because the thickness of a coated fabric is not a meaningful denominator.

  • Force at break (N): the force at the moment of rupture, which can be lower than the maximum when one element (coating or one set of yarns) fails first.

  • Elongation at maximum force and elongation at break (%): Method 1 only, expressed as a percentage of the nominal gauge length.

  • Direction: every result is given separately for the longitudinal (warp, machine) and transverse (weft, cross) directions, because coated fabrics are rarely balanced; a 2:1 ratio is common.

Both methods need a constant-rate-of-extension (CRE) machine: the crosshead moves at a uniform speed and the force is whatever the test piece demands. Pendulum (CRT) and constant-rate-of-loading machines are not permitted. The related standards on our site are the ISO 13934-1 strip test for uncoated fabrics, ASTM D751 for coated fabrics in the US system, and ASTM D5034 for the grab test on textiles; the textiles testing page gives the overview.

Editions: 1977, 1998 and ISO 1421:2016

The first edition dates from 1977, the second from 1998, and the current third edition, ISO 1421:2016, was published in November 2016. It was confirmed by systematic review in 2021 and again in June 2026, so it stays current. The European adoption is EN ISO 1421:2016, published nationally as BS EN ISO 1421:2017 and DIN EN ISO 1421:2017. The 2016 foreword lists the changes from 1998:

  • Gauge length and reference points defined. Nominal gauge length is the length between the jaw nips, or between two reference marks, under the specified pre-tension with the clamps in the start position; reference points are two lines, usually 100 mm apart and equidistant from the mid-point, that let elongation be measured on the specimen itself rather than from crosshead travel.

  • Conditioning clause split and clarified by reference to ISO 2231:1989.

  • New clause on time between manufacture and testing, so that results on freshly made material are not compared with aged production.

  • Two narrower strip widths, 30 mm and 10 mm, added to the strip test with pre-tension forces revised to suit, for narrow tapes and webbings that cannot yield a 50 mm strip.

  • Procedure for test pieces with reference marks incorporated into the strip method, and the handling of abnormal results (slippage, jaw breaks) revised.

Equipment pages that title the method ISO 1421:1998 are describing a superseded edition. The 50 mm strip, 100 mm/min, 200 mm jaw separation and the pre-tension table carried over unchanged, so the numbers on those pages are usually still right; the 10 and 30 mm widths and the reference-mark elongation are what they miss.

Method 1: The Strip Test

The strip test grips the full width of a parallel-sided strip and extends it to break. The complete parameter set:

  • Test pieces: at least 5 in the longitudinal and 5 in the transverse direction, cut from the sample away from the edges and distributed across the width. Width 50 ± 0.5 mm (the 2016 edition also allows 30 mm and 10 mm strips by agreement, with their own pre-tensions). On a woven base the strip is cut slightly wider and frayed down to 50 mm where the coating allows; on a knitted base the strip follows a wale or course; on a nonwoven base it is a clean rectangular cut.

  • Length: enough for a jaw separation of 200 ± 1 mm plus the gripped length at each end, about 50 mm per jaw, so 300 to 330 mm. When the elongation at break exceeds 75 %, the jaw separation is reduced to 100 ± 1 mm so the test finishes within the machine's travel; the shorter gauge must be reported.

  • Pre-tension: applied before the test to straighten the strip, chosen by mass per unit area and limited to 5 % elongation: 2 N for fabrics up to 200 g/m², 5 N for 200 to 500 g/m², 10 N above 500 g/m². Alternatively the strip is mounted slack and the force–extension curve is started at 0.5 N, the extension up to that point being added to the gauge length.

  • Rate of separation: 100 ± 10 mm/min unless otherwise agreed. On a 200 mm gauge that is 50 % of gauge length per minute; on a 100 mm gauge, 100 %/min.

  • Jaws: at least as wide as the test piece and preferably at least 60 mm; faces that hold without slipping or damaging the piece; capstan or other self-locking jaws are permitted and their use reported.

  • Wet testing: immerse at least 1 h at room temperature in water with up to 0.1 % wetting agent, blot, mount with half the pre-tension and test within one minute.

The strip test is the method that gives usable stress–strain data: the whole width is loaded uniformly, the elongation is measurable, and the result can be converted to force per unit width (N/50 mm, N/cm or kN/m) for design. It is also the method that produces jaw breaks on hard, slippery coatings, which is the whole reason the grab test exists as a fallback.

Method 2: The Grab Test

  • Test pieces: at least 5 per direction, 100 ± 2 mm wide and at least 150 mm long, with a line drawn 37 mm from one long edge along the full length; the piece is mounted with that line against the edge of the narrow jaw face so the central 25 mm of the width is gripped.

  • Jaw faces: one face of each clamp 25 ± 0.5 × 25 ± 0.5 mm; the opposing face at least 25 mm wide and preferably 50 mm, so the ungripped margins of fabric either side of the gripped strip can carry load into it.

  • Jaw separation: 100 ± 1 mm, or 75 ± 1 mm by agreement (the ASTM distance).

  • Rate: 100 ± 10 mm/min, the same as the strip test. Note that the grab test of ISO 13934-2 for uncoated fabrics runs at 50 mm/min and ASTM D751 at 300 mm/min; the ISO 1421 grab rate matches neither.

  • Result: maximum force only, mean per direction. No elongation is reported because the strain field in a grab piece is non-uniform.

Because the ungripped margins add an undefined contribution, grab forces are not convertible to force per unit width and cannot be compared with strip results. Published work on PVC-coated polyester membranes puts the strip maximum force at about 1.5 times the grab force in both directions at the standard geometries, with polyurethane-coated fabrics behaving differently again; grab tests also tend to fail at the clamp and to deform out of plane. The standard's own guidance is to use the strip test, and to move to the grab test only when every strip specimen breaks at the jaws despite careful gripping.

Machine, Clamps, Conditioning and Time After Manufacture

  • Testing machine: CRE type, class 1 per ISO 7500-1, force error within ± 1 %, jaw-separation error within 1 mm, rate uniform within 5 % after the first 2 s, data acquisition at 8 points per second or faster, and scales chosen so the breaking force falls between 15 % and 85 % of full scale.

  • Clamps: hold without slipping or damaging the piece; strip jaws ≥ piece width and preferably ≥ 60 mm; grab jaws 25 × 25 mm against ≥ 25 (preferably 50) mm; capstan or self-locking jaws allowed. Smooth faces, knurled faces, rubber or paper packing are all used depending on the coating; serrations that cut the coating cause jaw breaks.

  • Conditioning: one of the standard atmospheres of ISO 2231:1989, in practice 23 °C / 50 % RH or 20 °C / 65 % RH, for long enough to reach equilibrium (24 h is the usual figure), and the test run in the same atmosphere. Coated fabrics are hygroscopic through the base textile, so a strip tested straight from a damp warehouse can read several percent low.

  • Time after manufacture: the 2016 edition adds a clause fixing a minimum interval between coating and testing, so that incompletely cured or plasticiser-migrating coatings are not reported as finished product; the 1998 note to test within three months of manufacture for representative results still applies as good practice.

Rejection Rules: Slippage and Jaw Breaks

A result is discarded, and the piece replaced from the same part of the sample, if the piece slips asymmetrically in the jaws or by more than 2 mm, or if it breaks within 5 mm of a jaw face (a jaw break). The reasoning is that a jaw break reports the stress concentration at the nip, not the fabric, and typically reads 5 to 15 % low. Slippage is detected by marking the piece at the nips before the test and checking the marks afterwards, or from a force–extension curve that shows a sudden drop and recovery.

When all the strip specimens are jaw breaks despite changing faces, packing and clamping force, the standard sends you to the grab test, where the gripped width is only a quarter of the piece and the margins relieve the nip. In our experience the sequence that cures most jaw breaks on coated fabrics is: switch from knurled to smooth faces with a thin rubber or emery packing, reduce clamping force to the minimum that holds, then move to pneumatic grips whose force stays constant as the coating compresses; capstan jaws are the last resort for very strong membranes. The jaw-break guide goes through the diagnosis in detail.

Elongation: Three Gauge Bases

ISO 1421 defines elongation as the increase in length and percentage elongation as that increase divided by the nominal gauge length, but there are three legitimate gauge lengths and they give different numbers:

  • Pre-tensioned, jaw-to-jaw: the nominal gauge length is the jaw separation at the start, 200 mm (or 100 mm), after the pre-tension has been applied. 1 mm of crosshead travel is 0.5 % elongation at 200 mm.

  • Slack-mounted: the curve starts when the force reaches 0.5 N; the extension up to that point is added to the jaw separation to give the gauge length, and elongation is measured from there.

  • Reference marks (2016): two lines 100 mm apart centred on the piece, followed by a video extensometer or measured manually; this removes jaw slippage and the deformation of the gripped ends from the elongation and is the basis of choice when elongation is a specification value.

Elongations are recorded to the nearest 1 mm and the mean percentage rounded to 0.2 % below 8 %, 0.5 % from 8 to 50 % and 1 % above 50 %. Forces are recorded per piece and the means per direction rounded to the nearest 1 N or 1 % of the value, with coefficient of variation and confidence limits when required.

Step-by-Step Procedure (Strip Test)

  • 1. Sample and cut. Take at least 5 longitudinal and 5 transverse pieces from the conditioned sample, away from the edges and staggered across the width, 50 ± 0.5 mm wide (frayed to width on wovens) and about 320 mm long. Weigh a sample to get the mass per unit area and pick the pre-tension.

  • 2. Condition in the ISO 2231 atmosphere and keep the test in it.

  • 3. Set the machine: jaw separation 200 ± 1 mm (100 mm for > 75 % elongation), speed 100 ± 10 mm/min, load range chosen so the expected maximum falls at 15 to 85 % of scale, acquisition ≥ 8 Hz.

  • 4. Mount the piece centrally and square in the jaws, apply the 2, 5 or 10 N pre-tension (or mount slack and start the curve at 0.5 N), and mark the nips if slippage is to be checked.

  • 5. Extend to break, recording force against extension.

  • 6. Check validity: discard and replace pieces that slipped > 2 mm or asymmetrically, or broke within 5 mm of a jaw.

  • 7. Calculate: maximum force and force at break per piece; elongation at maximum force and at break as % of the gauge length; means per direction with the rounding rules; CV and confidence limits if required.

  • 8. Report: standard and method, sampling, number of pieces, atmosphere, gauge length and mounting (pre-tension or slack), dry or wet state, machine type and capacity, forces and elongations per direction, deviations, date.

Worked Example

A 650 g/m² PVC-coated polyester tarpaulin is tested in the warp direction by the strip method. Mass per unit area above 500 g/m² gives a 10 N pre-tension; at 10 N the strip extends 0.6 mm, 0.3 % of the 200 mm gauge, inside the 5 % limit. Five strips reach maximum forces of 2,610, 2,545, 2,680, 2,590 and 2,635 N at crosshead extensions of 46.0, 44.8, 47.2, 45.6 and 46.4 mm; all break in the gauge length more than 5 mm from the jaws.

  • Mean maximum force: (2,610 + 2,545 + 2,680 + 2,590 + 2,635) ÷ 5 = 13,060 ÷ 5 = 2,612 N → reported as 2,610 N per 50 mm (rounded to 1 % of value). Per width this is 52.2 N/mm or 52.2 kN/m, a figure the standard does not require but membrane designers use.

  • Elongation at maximum force: 46.0 ÷ 200 = 23.0 %; the five values 23.0, 22.4, 23.6, 22.8, 23.2 % average 23.0 %, in the 8 to 50 % band, so reported as 23.0 %.

  • Coefficient of variation: standard deviation 50 N on 2,612 N → 1.9 %.

  • Load cell: 2,680 N must sit between 15 and 85 % of scale → a 5 kN cell (54 %) is correct; a 10 kN cell (27 %) is acceptable; a 2.5 kN cell would be overloaded.

  • Grab check: the same fabric by Method 2 reads about 1,750 N maximum, two-thirds of the strip value, in line with the 1.5:1 ratio reported for PVC-coated polyester; the two numbers describe different things and are not interchangeable.

  • Test time: 46 mm at 100 mm/min is about 28 s, so a full direction of five pieces takes under five minutes of machine time.

Common Errors and How Much They Matter

  • Wrong tolerances. Several equipment pages give the strip width as 50 ± 5 mm and the grab width as 100 ± 5 mm; the standard says ± 0.5 mm and ± 2 mm. A strip 5 mm oversize reads 10 % high.

  • Grab test at the uncoated-fabric or ASTM rate. ISO 1421 grab is 100 mm/min; ISO 13934-2 is 50 mm/min and ASTM D751 is 300 mm/min. Coated fabrics are rate-sensitive through the coating, and the three rates do not give the same force.

  • Comparing strip and grab. Strip reads roughly 1.5 times grab on PVC-coated polyester and the ratio changes with coating and construction; the two are not comparable at all and should never appear in the same specification column.

  • Elongation from jaw travel when the piece slipped. 2 mm of slip on a 200 mm gauge is 1 % of elongation; on a 100 mm gauge it is 2 %. Mark the nips, or use reference marks and a video extensometer.

  • No pre-tension, or too much. Slack strips give elongations that include the straightening of the strip; a pre-tension that elongates the piece more than 5 % removes real elongation. Pick the force from the g/m² table.

  • Knurled faces on soft coatings. Diamond knurls bite through PU and soft PVC coatings and start jaw breaks, which read 5 to 15 % low; use smooth faces with packing, or rubber-lined faces.

  • Reporting stress. ISO 1421 reports newtons for a 50 mm strip. Dividing by thickness to get MPa is meaningless for a coated textile; dividing by width to get N/50 mm, N/cm or kN/m is fine if the width is measured.

  • Mixing directions. Longitudinal and transverse results are reported separately; averaging them hides a ratio that is often 1.5:1 to 2:1.

ISO 1421 vs ISO 13934-1, ISO 13934-2 and ASTM D751

The figures for ASTM D751 match our ASTM D751 guide; the ISO 13934 figures match the ISO 13934-1 guide.

  • ISO 1421 Method 1 (strip, coated): 50 ± 0.5 mm (30 and 10 mm options), jaw separation 200 mm (100 mm if > 75 %), pre-tension 2/5/10 N, 100 ± 10 mm/min, ≥ 5 per direction, jaws ≥ 60 mm preferred, max force, force at break, elongations; ISO 2231 conditioning.

  • ISO 1421 Method 2 (grab, coated): 100 ± 2 × ≥ 150 mm, line 37 mm from the edge, 25 × 25 mm face opposite ≥ 25 (50) mm, separation 100 (75) mm, 100 mm/min, max force only.

  • ISO 13934-1 (strip, uncoated): 50 ± 0.5 mm ravelled strip, 200 mm (100 mm if > 75 %), pre-tension 2/5/10 N, 20 mm/min below 8 % elongation, 100 mm/min above, ≥ 5 per direction, ISO 139 atmosphere 20 °C / 65 % RH; states it is usually not applicable to coated fabrics.

  • ISO 13934-2 (grab, uncoated): 100 ± 2 mm wide, 25 × 25 mm faces, line 38 mm from the edge, separation 100 (75) mm, 50 mm/min.

  • ASTM D751 Procedure A (grab, coated): 100 × 150 mm piece, front jaw 25 × 25 mm, rear 25 × 50 mm, gauge 75 mm, 300 mm/min; Procedure B cut strip 25 mm wide at 75 mm and 300 mm/min with elongation by bench marks; ≥ 5 per direction.

A laboratory that runs both ISO and ASTM coated-fabric work therefore keeps two grab jaw sets (ISO 25 × 25 against 50 mm; ASTM 25 × 25 against 25 × 50 mm, functionally the same hardware), two gauge settings (100 and 75 mm) and two speeds (100 and 300 mm/min), and never puts the two results in the same table. ISO 1421 and ISO 13934-1 strip tests share hardware and gauge but differ in speed for low-elongation fabrics (100 versus 20 mm/min) and in conditioning atmosphere.

Equipment: Jaw Faces, Grips and Machines from Universal Grip

Universal Grip's ISO 1421 vise grip jaw faces (part UGC-ISO1421-VG) are interchangeable jaw faces for screw-action vise grips used in tensile testing of coated fabrics. A smooth face and a diamond-knurled face can be paired to suit the coating, holding wide strips firmly without slippage or premature failure at the jaw edge. Per the data sheet: diamond-knurled face for hard or slippery coatings, smooth face for soft coatings or with cushioning, wide faces that accept strip and grab specimens, counterbored holes for fast exchange on the vise body, hardened steel for long service life; 5 kN standard capacity, higher on request; surfaces diamond-knurled or smooth, rubber-lined on request; jaw width approximately 80 mm typical, others on request; fits the matching vise grip body. Applications on the sheet: PVC- and PU-coated fabrics, rubber-coated technical textiles, tarpaulins, awnings and inflatables, conveyor and protective-clothing fabrics.

For the strip test the 80 mm faces exceed the standard's preferred 60 mm minimum and cover the 50 mm strip with margin, and the smooth-plus-knurled pairing is the standard's own recipe for holding a coated strip without jaw breaks. For the grab test the standard requires a 25 × 25 mm face on one side of each clamp opposite a face at least 25 mm (preferably 50 mm) wide; the 80 mm face serves as the wide back face and we recommend ordering a 25 × 25 mm grab insert for the front face so the same vise body runs both methods.

  • Grips: screw-action vise grips with these faces for strips up to 5 kN; pneumatic grips with 60 to 100 mm faces where the constant clamping force is needed to stop slippage on thick PVC or creep on PU coatings, and for high-throughput QC; capstan grips for architectural membranes above 5 kN per 50 mm.

  • Testing machines: a Mark-10 tester for awning and apparel fabrics up to 1.5 kN, the 5 kN benchtop UTM for tarpaulins and inflatables, and 10 to 25 kN frames for truck-side curtains and structural membranes; all with 100 mm/min within ± 10 % and 8 Hz or faster acquisition.

  • Elongation: a video extensometer reading the 100 mm reference marks removes jaw slippage from the elongation and is the clean way to meet the 2016 reference-point method.

  • Specimen preparation: 50 mm and 100 mm strip cutters and cutting dies, a 37 mm marking gauge for grab pieces, and a balance for mass per unit area to pick the pre-tension.

  • Conditioning and wet tests: environmental chambers for tests at service temperature, and an immersion tank for the one-hour wet soak.

  • Related guides: ISO 13934-1, ASTM D751, ASTM D5034, ISO 2062 for yarns, the textiles testing page and the ISO standards library.

ISO 1421 FAQ

What is the test speed in ISO 1421?

100 ± 10 mm/min for both the strip test and the grab test, unless otherwise agreed. That is 50 % of gauge length per minute on the 200 mm strip gauge and 100 %/min on the 100 mm gauge used for fabrics that elongate more than 75 %.

What are the ISO 1421 strip test specimen dimensions?

50 ± 0.5 mm wide (30 mm and 10 mm permitted since 2016), long enough for a 200 ± 1 mm jaw separation plus about 50 mm in each jaw, so roughly 300 to 330 mm. At least 5 pieces in the longitudinal and 5 in the transverse direction.

What are the grab test dimensions in ISO 1421?

100 ± 2 mm wide and at least 150 mm long, with a line 37 mm from one edge aligned to the jaw so the central 25 mm is gripped; one jaw face 25 ± 0.5 × 25 ± 0.5 mm opposite a face at least 25 mm (preferably 50 mm) wide; jaw separation 100 mm or 75 mm by agreement; maximum force only.

How much pre-tension does ISO 1421 specify?

2 N for fabrics up to 200 g/m², 5 N for 200 to 500 g/m² and 10 N above 500 g/m², limited so that it produces no more than 5 % elongation. Alternatively the piece is mounted slack and the curve started at 0.5 N. Wet pieces get half the pre-tension.

What is a jaw break in ISO 1421 and what happens to it?

A break within 5 mm of a jaw face. The result is discarded and the piece replaced; so is any piece that slips more than 2 mm or asymmetrically. If every strip specimen is a jaw break despite careful gripping, the standard directs you to the grab test.

Which is the current edition of ISO 1421?

ISO 1421:2016, the third edition, confirmed in 2021 and June 2026; the European version is EN ISO 1421:2016 (BS EN ISO 1421:2017). It added defined gauge length and reference points, 30 mm and 10 mm strip widths, a time-after-manufacture clause and revised abnormal-result handling over the 1998 edition.

Are strip and grab results comparable?

No. The grab test loads only the central 25 mm of a 100 mm piece and the ungripped margins add an undefined contribution. On PVC-coated polyester the strip maximum force is about 1.5 times the grab force; the ratio differs for other coatings. The standard treats grab as the fallback when strip pieces only give jaw breaks.

What unit does ISO 1421 report?

Force in newtons, as the mean maximum force and force at break for the 50 mm strip (or 100 mm grab piece) per direction, rounded to 1 N or 1 % of the value, plus elongation in %. It does not report stress in MPa; dividing by the measured width to give N/50 mm, N/cm or kN/m is common practice for design.

What jaw faces should I use for coated fabrics?

Faces at least as wide as the strip and preferably 60 mm or more: smooth faces with rubber or paper packing for soft PU and PVC coatings, diamond-knurled faces for hard or slippery coatings, rubber-lined faces when both slip and jaw breaks are a problem, and capstan or self-locking jaws (permitted and reported) for very strong membranes. For the grab test one face per clamp must be 25 × 25 mm.

How does ISO 1421 differ from ISO 13934-1?

ISO 13934-1 is the strip test for uncoated fabrics and says it is usually not applicable to coated fabrics. Both use a 50 mm strip and 200 mm gauge with 2/5/10 N pre-tension, but ISO 13934-1 runs at 20 mm/min for fabrics below 8 % elongation and conditions at 20 °C / 65 % RH, while ISO 1421 runs at 100 mm/min for everything and conditions per ISO 2231.

How does ISO 1421 compare with ASTM D751?

ASTM D751 Procedure A is a grab test on a 100 × 150 mm piece with a 25 × 25 mm front jaw, a 75 mm gauge and 300 mm/min; Procedure B is a 25 mm cut strip at 75 mm and 300 mm/min. ISO 1421 uses a 50 mm strip at 200 mm and a grab at 100 mm, both at 100 mm/min. Same hardware, different gauges and a threefold speed difference, so results are not interchangeable.

What load cell and machine do I need for ISO 1421?

The breaking force must fall between 15 % and 85 % of scale on a class 1 CRE machine: a 1 kN cell for awning and apparel fabrics, 5 kN for tarpaulins and inflatables (a 2,600 N strip reads at 52 %), and 10 to 25 kN for architectural membranes and truck curtains. Acquisition must be at least 8 points per second.

Need vise grips, pneumatic grips or a complete tensile system for ISO 1421 coated fabric testing? Contact Universal Grip with your fabric type, coating, expected breaking force and machine connection and we will quote the right setup.

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