ASTM D2261
Tongue Tear Test
Downloads: ASTM D2261-07a standard, 2007 edition (PDF)
Written by Chris Thomas, Universal Grip Company · Reviewed by Frank Bertini · Updated October 23, 2026
ASTM D2261-13(2024) measures the tearing strength of textile fabrics by the tongue (single rip) procedure on a constant-rate-of-extension (CRE) tensile tester. A slit cut into the specimen forms two tongues; each tongue is clamped in a jaw and the tear is pulled along the fabric. Because the tear is started before the test, the result is the force needed to continue a tear, not to start one.
The method dates from 1964 and is under subcommittee D13.60. It covers most fabrics: woven, knit, nonwoven, layered, pile, napped, blanket and airbag fabrics, treated or untreated, tested wet or dry. It is accepted for acceptance testing of commercial shipments, although tear values are comparative rather than an absolute minimum strength.
ASTM D2261 at a glance
Current edition: D2261-13, reapproved 2024: D2261-13(2024)
Machine: CRE tensile tester (a CRT tester only by purchaser/supplier agreement, per the appendix)
Specimen: 75 × 200 mm (3 × 8 in) ± 1 mm
Slit: 75 ± 1 mm (3 in) cut from the centre of the 75 mm edge, forming two 37.5 mm tongues
Jaw distance at start: 75 ± 1 mm (3.0 ± 0.05 in)
Speed: 50 ± 2 mm/min (2 ± 0.1 in/min); 300 ± 10 mm/min (12 ± 0.5 in/min) only by agreement
Clamp faces: at least 25 × 75 mm (1 × 3 in), long side perpendicular to the pull
Specimens: 5 machine-direction + 5 cross-machine-direction per test condition
Conditioning: standard textile atmosphere per ASTM D1776/D1776M
Result: single-peak force, or the average of the five highest peak forces, in N (lbf)
Note: The default speed is 50 mm/min. 300 mm/min is an option only when purchaser and supplier agree, and the speed used must be reported.
What D2261 measures and who uses it
Tear resistance decides whether a small cut, snag or puncture stays small or runs across a garment, tarp, airbag cushion or upholstery panel. The tongue tear isolates that behaviour: the tear front advances through the fabric one yarn or bond at a time, and the tester records how much force each step takes.
Fabric mills and converters: lot acceptance and comparison against purchase specifications
Apparel, home furnishing and upholstery makers: incoming inspection and supplier qualification
Technical and industrial textiles: airbag, protective, coated and filtration fabrics
Nonwoven producers: checking how bonding and fibre orientation affect tear propagation
R&D labs: comparing weaves, finishes and coatings, which can change tear strength significantly
Because tear force depends on how yarns bunch and slide at the tear front, a tight, heavily finished fabric can tear at a lower force than a looser fabric with weaker yarns. That is why tongue tear is specified alongside, not instead of, a tensile test.
Specimens and cutting
Cut each specimen 75 × 200 mm (3 × 8 in) ± 1 mm with a die or template. Make a 75 ± 1 mm (3 in) slit at the centre of one short edge, parallel to the long side. The slit creates two 37.5 mm wide tongues and leaves 125 mm of untorn fabric for the tear to travel through.
Take 5 specimens in the machine direction and 5 in the cross-machine direction for each test condition
Label each specimen by direction exactly as the standard defines it; the short direction is the direction of test
Take specimens from across the width of the laboratory sample, away from the selvages
Avoid creases, folds and visible defects in the tear path
For lot sampling, take a full-width swatch about 1 m (1 yd) long from each roll sampled
Lot sampling follows the standard's table: all rolls for lots of 1–3 rolls, 4 rolls for 4–24, 5 rolls for 25–50, and 10 % (maximum 10 rolls) above 50.
Grips and data acquisition
D2261 requires parallel, flat clamps with gripping faces at least 25 × 75 mm (1 × 3 in), with the 75 mm side perpendicular to the pull. Each 37.5 mm tongue must sit fully inside the jaw face, so narrow tensile jaws do not work.
Pneumatic clamps: the most common choice. Constant clamping force on every specimen, fast loading, and no operator-to-operator torque variation
Manual vise-type clamps: allowed if the fabric does not slip
Faces: rubber faces for smooth or coated fabrics, serrated faces for heavy or slippery fabrics; medium-grit emery cloth lining is a long-standing option for slippage (check the current edition for details)
Width: faces of 50 × 75 mm or larger give more grip area and are typical of recommended clamps
Slippage shows as a gradual force drop with the tongue sliding out of the jaw, often leaving polished marks on the fabric. Jaw damage shows as cut yarns at the jaw edge. Both invalidate the specimen.
Tongue tear forces are low, usually well under 5 kN, so a small-capacity load cell gives the best resolution. Set the force range so the maximum force falls between 10 % and 90 % of full scale. Sample fast enough to capture every peak: the tear advances yarn by yarn, and a slow data rate clips the peaks and under-reports the result.
Conditioning
Bring specimens to moisture equilibrium in the standard atmosphere for testing textiles, 21 °C and 65 % RH within the tolerances of ASTM D1776/D1776M, unless the material specification or contract says otherwise. Textile labs use 65 % RH, not the 50 % RH used for plastics. Wet testing is permitted; follow the wet-specimen procedure in the current edition and report that the specimens were tested wet.
Test procedure, step by step
Condition specimens and test in the standard textile atmosphere
Set the jaw distance to 75 ± 1 mm (3 in) and the speed to 50 ± 2 mm/min (or 300 mm/min if agreed)
Select a force range so the peak falls between 10 % and 90 % of full scale
Clamp one tongue in the upper jaw and the other in the lower jaw, with the cut edges on the centreline of the jaws and the untorn end hanging free
Start the test and propagate the tear through the specimen, following the stop marks given in the standard's figure
Watch the tear path: note any tear that runs out of line, yarn pull-out or jaw slippage
Record the force–extension curve and calculate the single-peak or five-highest-peaks result
Repeat for 5 specimens in each direction
Calculating the result and worked example
A tongue tear curve is a series of peaks and valleys. Each peak is the force at which a yarn (or group of yarns or bonds) resists the tear before rupturing; each valley is the force between ruptures. The standard states that the highest peaks reflect the strength of the components that stop the tear and that the valleys have no specific significance.
Single-peak force: for specimens that show only one peak, record the maximum force
Average of the five highest peaks: for specimens with multiple peaks, average the five highest peak forces during the tear
The standard sets out how a peak is identified, which parts of the curve to exclude and what to do with specimens that give fewer than five peaks. Check those rules in the current edition and set them in your software before testing. Report the result in N (lbf). It is a force, not a stress, so do not divide by width or thickness.
Worked example
Machine-direction specimen 1, five highest peaks: 42.1, 40.8, 41.2, 39.5 and 38.9 N
Sum = 202.5 N; average = 202.5 / 5 = 40.5 N (9.1 lbf)
Specimens 1–5 give 40.5, 38.7, 41.9, 39.6 and 40.8 N; sum = 201.5 N
Machine-direction tear strength = 201.5 / 5 = 40.3 N (9.1 lbf)
Repeat for the cross-machine direction and report the two directions separately. Never average across directions.
Invalid tears and troubleshooting
Tear runs out of line or across one tongue (transverse tear): common in loosely woven fabrics with strong yarns; record it and report it as an abnormal tear
Yarn pull-out instead of rupture: the yarns slide out of the weave; the result reflects fabric construction rather than yarn strength and should be noted
Slippage in the jaws: increase clamping force or change faces; discard the result
Break at the jaw edge: soften the faces or reduce clamping pressure
Peak force outside 10–90 % of the force range: change the range and retest
Check the current edition for exactly how abnormal tears must be reported. A report typically includes the edition, fabric identification, direction, wet or dry, speed, clamp type and faces, the calculation option used, individual and average values, and any abnormal tears.
50 mm/min vs 300 mm/min
The default rate in D2261 is 50 ± 2 mm/min. The 300 mm/min rate is permitted only when purchaser and supplier agree, and it gives different values from the default rate, so results at the two speeds are not interchangeable. Some published summaries, including older text on this site, listed 300 mm/min as the D2261 speed; that is the agreed option, not the default.
In practice: run 50 mm/min unless a contract or customer specification names 300 mm/min in writing, keep the agreed speed on the test report, and do not compare data across speeds. If you inherit a historical database, check which speed it was built at before using it as a baseline.
D2261 vs D5587, D1424 and ISO tear tests
ASTM D2261 (tongue tear): two tongues pulled apart along a pre-cut slit at 50 mm/min on a CRE tester; result from the highest peaks
ASTM D5587 (trapezoid tear): a 75 × 150 mm specimen marked with a trapezoid and clamped along its non-parallel sides at a 25 mm gauge, tested at 300 mm/min
ASTM D1424 (Elmendorf): a falling pendulum tears the specimen in one swing; no tensile machine is used
ISO 13937-2 (single tear, trouser shape): the closest ISO method, but with a different specimen geometry and speed
There is no exact ISO equivalent, and results do not convert between methods. For fabric tensile strength, see the grab test ASTM D5034 and the strip test ASTM D5035. Our tear testing page compares the tear methods, and the textile testing blog post covers a complete fabric lab setup.
D2261 equipment from Universal Grip
Universal Grip makes textile vise grips and supplies Galdabini universal testing machines for fabric testing. A D2261 system typically includes:
A low-capacity frame with a load cell sized for the fabric, usually well under 5 kN
Flat-faced pneumatic grips or textile vise grips wide enough for 75 mm jaw faces
Rubber or serrated faces matched to the fabric
Software with peak detection for single-peak and five-highest-peaks results
The same frame and grips run D5034, D5035 and D5587 with a change of faces and settings. See our textiles page for the full range, and tell us your fabric type and the methods you run. Contact us for a quote.
ASTM D2261 FAQ
What is the ASTM D2261 tongue tear test?
ASTM D2261 is a tongue (single rip) tear test for fabrics run on a constant-rate-of-extension tensile tester. A 75 mm slit cut into a 75 × 200 mm specimen forms two tongues, one clamped in each jaw, and the tear is pulled through the fabric. The result is the force to continue a tear, not the force to start one.
What is the specimen size for ASTM D2261?
The specimen is 75 × 200 mm (3 × 8 in) ± 1 mm with a 75 ± 1 mm (3 in) slit cut at the centre of one short edge, parallel to the long side. The slit forms two 37.5 mm wide tongues. Test five specimens in the machine direction and five in the cross-machine direction for each condition.
What test speed does ASTM D2261 use?
The standard speed is 50 ± 2 mm/min (2 ± 0.1 in/min). A speed of 300 ± 10 mm/min (12 ± 0.5 in/min) may be used only if the purchaser and supplier agree. Results at the two speeds are not interchangeable, so always report which speed was used.
What is the jaw distance for ASTM D2261?
The distance between the clamps at the start of the test is 75 ± 1 mm (3.0 ± 0.05 in). One tongue is clamped in each jaw with the cut edges on the centreline of the jaws, and the untorn part of the specimen hangs free between them as the tear propagates.
How is tongue tear strength calculated?
For specimens with a single peak, the result is the maximum force. For specimens with multiple peaks, the result is the average of the five highest peak forces during the tear. The valleys between peaks are ignored. Results are reported in newtons or pounds-force for each direction separately, as a force rather than a stress.
What is the difference between tongue tear and trapezoid tear?
Tongue tear (ASTM D2261) pulls two tongues apart along a pre-cut slit at 50 mm/min. Trapezoid tear (ASTM D5587) clamps a specimen along the non-parallel sides of a marked trapezoid at a 25 mm gauge and pulls at 300 mm/min. The geometries load the yarns differently, so the results are not interchangeable.
What is the difference between ASTM D2261 and the Elmendorf test?
ASTM D2261 uses a tensile machine running at a constant rate of extension and records a full tear curve, from which the highest peaks are taken. The Elmendorf test, ASTM D1424, uses a falling pendulum that tears the specimen in one swing and reports a tearing force derived from the energy it loses. The results are not interchangeable.
What grips are used for ASTM D2261?
Flat, parallel clamps with gripping faces at least 25 × 75 mm, with the long side perpendicular to the pull. Pneumatic clamps with 50 × 75 mm or larger rubber or serrated faces are typical. Manual clamps are allowed if the fabric does not slip, and emery cloth lining can help with slippery fabrics.
Is there an ISO equivalent to ASTM D2261?
There is no exact ISO equivalent. ISO 13937-2, the single-tear trouser-shaped method, is the closest, but it uses a different specimen geometry and test speed. Results from the two methods do not convert, so test to the method named in your specification.
Does ASTM D2261 apply to nonwovens and knits?
Yes. The scope covers most textile fabrics, including woven, knit, nonwoven, layered, pile, napped, blanket and airbag fabrics. Fabrics may be treated or untreated and tested wet or dry. Report any specimen in which the tear runs out of line rather than along the slit.
How should ASTM D2261 specimens be conditioned?
Bring specimens to moisture equilibrium in the standard atmosphere for testing textiles defined in ASTM D1776/D1776M, which is 21 °C and 65 % relative humidity within the tolerances that standard sets, unless the material specification or contract specifies otherwise. Test in the same atmosphere, and report any wet testing.
What is the current version of ASTM D2261?
The current edition is ASTM D2261-13, reapproved in 2024 and designated D2261-13(2024), under subcommittee D13.60 on fabric test methods. The method was first published in 1964. Older editions such as D2261-07a are still in circulation, so confirm the edition your specification requires.