ASTM D903 Complete Guide: 180° Peel Strength Test, Specimens, Speed, Fixtures and Calculations
ASTM D903 is the classic 180° peel test for adhesive bonds: a flexible strip bonded to a rigid strip is folded back on itself and pulled off at a steady rate, and the average force per unit width is the peel strength. It looks like the simplest test in the adhesives lab, which is why it goes wrong so often. The most common mistake is the speed: D903 runs the moving grip at 305 mm/min (12 in/min) so the bond separates at 152 mm/min (6 in/min), and many labs set the crosshead to 152 mm/min and peel at half the specified rate. Others average the wrong part of the trace, let the specimen swing out of plane, or peel only a few centimetres of the bond. This complete guide covers the specimen and its dimensions, preparation and conditioning, the speed rule, which testing machine to use (a Mark-10 tensile tester or a Galdabini universal testing machine), peel grips and fixtures, why you do not need an extensometer (and where a video system still helps), the procedure, how to calculate average peel strength from the trace with a worked example, D903 vs. ISO 8510-2, D3330 and T-peel, troubleshooting and a full FAQ.
For the standard reference page with fixture photos and downloads, see our ASTM D903 180° peel test page. If both of your adherends are flexible, the T-peel test is usually the better method; our companion ASTM D1876 T-peel complete guide covers it in the same depth.
ASTM D903 at a glance
Full title: Standard Test Method for Peel or Stripping Strength of Adhesive Bonds (D903-98, reapproved without technical change, most recently in 2025).
What it measures: the average load per unit width of bond line needed to separate a flexible member progressively from a rigid (or second flexible) member at about 180°.
Specimen: a flexible adherend 25 mm (1 in) wide by 305 mm (12 in) long, bonded over 152 mm (6 in) to a second adherend 25 mm wide by 203 mm (8 in) long.
Adherend thickness: enough to carry the pull, but no more than 3 mm (1/8 in).
Speed: the moving grip travels at 305 mm/min (12 in/min), giving a separation (peel) rate of 152 mm/min (6 in/min).
Peel length: at least half of the bonded area, about 76 mm (3 in) of bond.
Machine: constant rate of jaw separation, load accurate within 1 %, a continuous load-separation record, and test loads between 15 % and 85 % of capacity.
Conditioning: 7 days at 23 ± 1 °C and 50 ± 2 % RH, unless the adhesive manufacturer specifies otherwise.
Specimens: at least ten per adhesive.
Result: average peel load divided by width for each specimen, with the series mean, maximum and minimum, in N/mm or lbf/in.
What ASTM D903 measures and who uses it
Peel is how most flexible adhesive joints fail in service. A lap shear test such as ASTM D1002 loads the whole bond area at once; a peel test concentrates the load on a thin line at the separation front and drives that line through the bond. Two adhesives with the same shear strength can differ tenfold in peel, so peel strength is the property that matters for fabric, rubber, vinyl, foam, film, foil, leather and flexible laminates bonded to metal, wood, plastic or glass.
D903 is deliberately generic. It fixes the specimen geometry, angle, rate and conditions, but not the adherends or adhesive. That makes it a comparative test: it ranks adhesives, surface preparations, primers, cure schedules and suppliers under identical conditions. It does not give a design property, and values from different adherend combinations are not comparable. Adhesive manufacturers use it for data sheets and batch release; automotive, construction, footwear and consumer product suppliers use it for trim, flooring, membranes, laminated panels and sole bonds; quality labs use it to approve adhesive lots and check bonding processes.
For pressure-sensitive tapes and labels, ASTM D3330 usually applies instead, and when both adherends are flexible, ASTM D1876 (T-peel) is normally the better choice.
ASTM D903 specimen: dimensions and construction
D903 uses one specimen design for every material combination. The values below are nominal; take tolerances from the current edition.
Flexible adherend: 25 mm (1 in) wide by 305 mm (12 in) long. The first 152 mm (6 in) are bonded; the remaining 152 mm is the tail that is folded back and gripped.
Second adherend (rigid or flexible): 25 mm wide by 203 mm (8 in) long, bonded over 152 mm, leaving about 51 mm (2 in) unbonded for the lower grip.
"Flexible" defined: an adherend that can be bent back about 180° under the expected load without cracking or failing. At least one adherend must qualify.
Thickness: no more than 3 mm (1/8 in). The standard lists typical values of about 1.6 mm (1/16 in) for metal and plastic, 3 mm (1/8 in) for wood and 1.9 mm (0.075 in) for rubber, with a heavy cotton duck as the reference fabric.
Extensibility: the flexible member must be relatively non-extensible at the peel load so the separation rate stays as set. If it stretches, back it with a non-extensible material and describe the backing in the report.
Cutting specimens from bonded panels
The standard recommends bonding panels about 152 mm (6 in) wide and cutting them into five 25 mm specimens. Every specimen from a panel then shares the same surface preparation, adhesive spread, pressure and cure, so the scatter you measure belongs to the adhesive.
Cut cleanly, without heat: a fine saw or shear for rigid adherends; a sharp blade or cutting die on an arbor press for rubber, fabric and film. Crushed or frayed edges start the peel early.
Measure the width: peel strength is divided by width, so a 24 mm strip reads 4 % high against a nominal 25 mm.
Trim panel edges where squeeze-out and edge effects make the bond unrepresentative, and mark specimens by panel so a bad panel shows up as a group.
Bonding, preparation and conditioning
D903 hands the bonding procedure to the adhesive manufacturer, and that hides most of the variability in the test. Write your procedure down: surface preparation (a change from solvent wipe to abrade-and-wipe can double the peel value on metal), coat weight and open time for contact and solvent-borne adhesives, bonding pressure or roller passes, masking so no adhesive bridges into the tail, and the actual cure schedule.
Condition for 7 days at 23 ± 1 °C (73.4 ± 2 °F) and 50 ± 2 % RH, or until equilibrium. Desiccators with a saturated salt solution can provide the atmosphere; saturated calcium nitrate gives about 51 % RH.
The adhesive manufacturer may state that ageing is unnecessary or a shorter period is enough, and purchaser and supplier can agree special conditioning. Record what you did.
Test as soon as possible after conditioning, preferably in the same atmosphere. Wood, paper, fabric and polyamide adherends change quickly with humidity.
ASTM D903 test speed: 305 mm/min crosshead, 152 mm/min peel
This is the most misunderstood number in D903. The standard defines peel strength at a separation rate of 152 mm/min (6 in/min) and requires the power-actuated grip to travel at 305 mm/min (12 in/min) to produce it. In a 180° peel the tail is folded back on itself, so each millimetre of bond that separates lets the grip move two millimetres. The crosshead runs at twice the peel rate.
Set the crosshead to 305 mm/min. At 152 mm/min the bond peels at 76 mm/min, and most adhesives read low at a lower rate.
Hold the rate through the stick-slip. The frame must keep a constant speed under a fluctuating load, from the first millimetre. Motorized frames with closed-loop speed control do this; hand-cranked stands do not.
Clarify old wording. Some specifications say "D903 at 6 in/min" without saying it is the separation rate. Confirm with your customer and report the crosshead speed you used.
Machine requirements and sizing
The standard calls for a constant rate of jaw separation, load accurate within 1 %, grips that never slip, no maximum-load hold, a continuous (autographic) record of load against separation, and a maximum test load between 15 % and 85 % of rated capacity. Today the record is the load-travel trace stored by the software.
Load cell: most D903 specimens peel at a few newtons to a few hundred newtons. A 100 N peel needs a cell of roughly 120 to 670 N to satisfy the 15 to 85 % rule; a 20 N peel needs about 24 to 130 N. Size the load cell, not just the frame.
Travel: peeling half the bond (76 mm) takes about 152 mm of crosshead travel; peeling all 152 mm takes about 305 mm, plus take-up.
Data rate: sample fast enough to resolve peaks and troughs; a slow, filtered signal smooths stick-slip and can bias the average.
Which testing machine for ASTM D903: Mark-10 or Galdabini?
D903 is a low-force, constant-speed test, which makes it an excellent fit for a Mark-10 motorized tester. A Galdabini universal testing machine is the better choice when peel is one test among many in an advanced adhesives lab, or when you need testing at temperature.
Mark-10 tensile testers: the natural fit for D903 QC
100 lb (F105): 100 lbF (about 450 N) capacity suits nearly every D903 specimen and gives the best low-force resolution. 18 in (457 mm) of travel and a standard speed range to 13 in/min (330 mm/min), so 305 mm/min needs no speed option.
300 lb (F305) and 500 lb (F505): the same travel and speed range, for stands that also run lap shear or other higher-force tests.
750 lb (F755) and 1,500 lb (F1505): 32 in (813 mm) of travel and 10 to 600 mm/min, for labs that also run long-travel tests or full-length T-peels.
All F-series frames hold speed to ±0.2 % of setting and sample load at 5,000 Hz, which captures every peak and trough in a peel trace.
Pick the load cell so your peel loads sit between 15 % and 85 % of its capacity, and use software that stores the full trace so you can average the peel region. A manual tensile tester cannot hold a constant 305 mm/min, so it suits quick shop-floor checks but not D903 results. Compare the two machine families in Mark-10 test frame vs. universal testing machine, or see every model on the tensile testers page.
Galdabini universal testing machines: advanced adhesive labs
2.5 kN Quasar: single column, up to 1,000 mm/min and 1 m of stroke. The open front makes loading folded peel specimens easy.
5 kN Quasar: dual column with 175 mm of column clearance, the usual choice with an environmental chamber.
10 kN Quasar: for labs that also run ASTM D1002 lap shear and other structural adhesive tests.
With UTM test software you save a D903 method at 305 mm/min, define the averaging window by peel distance and report individual, mean, maximum and minimum values automatically. See the universal testing machine buyer's guide and the benchtop UTM range.
Choose a Mark-10 for production QC, incoming adhesive inspection and supplier approval, where you need compliant speed, a clean trace and a small footprint.
Choose a Galdabini UTM for adhesive development, multi-method labs, testing from −80 to +280 °C, or one frame that also runs lap shear, tensile and flexure.
Peel grips and fixtures for ASTM D903
A D903 setup needs a grip that holds the rigid adherend without slipping, a grip that holds the folded-back flexible tail squarely across its full width, and a way to keep the specimen in the plane of the clamps, a requirement many setups ignore. Our peel test fixtures and peel testing applications page show the options.
Holding the rigid adherend
Screw-action vise grips with serrated faces are the usual choice for the 51 mm unbonded end of a metal, plastic or wood strip. Mechanical wedge grips tighten as load rises and hold thin metal strips securely; they are more grip than D903 needs but convenient if the frame already carries them for lap shear. Pneumatic grips add fast, operator-independent clamping for high-volume QC. The standard also allows an alignment plate on the stationary clamp: the rigid adherend rests against it so the bond line stays in the grip plane and the angle stays near 180°.
Holding the flexible tail
Pneumatic grips: the preferred grip for fabric, rubber, film and foil tails, with constant air-set clamping across the full width and a foot pedal that frees both hands to align the tail. Our 2.4 kN centric and 2.6 kN grips for elastomers and films match peel loads well.
Roller grips: self-tightening eccentric grips that clamp harder as the pull rises, so a slippery coated fabric or rubber tail cannot creep out. No air supply is needed, which suits Mark-10 frames; sizes run from 100 N mini grips to 20 kN.
Vise grips: adequate for stiff, non-slippery tails at low force if the jaw is wider than the strip and tightened evenly.
Alignment: keeping the peel at 180°
If nothing holds the rigid member in line, it swings away from the axis as the peel runs, the angle drops below 180° and the load drifts. The standard gives two remedies: hang the minimum weight needed on the free end to keep the specimen in the plane of the clamps (and allow for it when evaluating the load), or hold the specimen against an alignment plate. Either way, centre the strip on the grip axis, clamp the tail symmetrically and without twist, use jaws at least 25 mm wide, and check from the side that the tail runs straight back along the bond. Our grips fit Mark-10, Instron, MTS, ZwickRoell, Shimadzu and Tinius Olsen frames with the right grip adapters; see the tensile grips page, the adhesive testing page and our peel test fixtures guide.
Do you need an extensometer for ASTM D903?
No. D903 peel strength is a force divided by width, and crosshead travel gives the separation directly (halved for a 180° peel). There is no strain to measure, and a clip-on or long-travel extensometer has nothing useful to attach to. You do not need an extensometer to comply with D903.
A camera does add value in documenting how the bond failed, which matters as much as the number:
Recording failure mode. D903 asks you to report the type of failure. Video of the peel front shows whether the bond failed adhesively at one surface, cohesively in the adhesive, by tearing the substrate, or by switching modes partway along the bond, and lets you match those changes to steps in the trace.
Checking angle and alignment. A side view shows whether the tail stayed at 180° or the rigid member swung out of plane, the usual cause of a drifting trace.
Measuring an extensible tail. Tracking a mark on the tail with a video extensometer shows whether it stretches enough to need the backing the standard calls for.
Testing in a chamber. A non-contact camera watches the peel front through the chamber window without opening the door.
If you already own a video extensometer for tensile work, such as the UGC-VE-2109 with its 220 mm field of view at ISO 9513 Class 0.5, it can record your peel tests too. If peel is all you run, a simple camera and good lighting is enough. The video extensometer buying guide and types of extensometers explain when a full system is worth it.
ASTM D903 test procedure, step by step
Step 1: Bond panels to the adhesive manufacturer's procedure, cure, and cut at least ten 25 mm specimens. Discard panel edges and flawed specimens.
Step 2: Condition for 7 days at 23 ± 1 °C and 50 ± 2 % RH, or as agreed.
Step 3: Measure each width at several points along the bond and record the average, the adherends and any backing.
Step 4: Set the crosshead to 305 mm/min (12 in/min), fit a load cell that puts the expected load between 15 % and 85 % of capacity, and zero it.
Step 5: Separate the free end of the flexible member by hand for about 25 mm (1 in).
Step 6: Clamp the free end of the 203 mm adherend in one grip. Fold the flexible tail back 180° and clamp it symmetrically, without twist, in the other.
Step 7: Keep the specimen in the plane of the clamps with an alignment plate or the minimum hanging weight. Remove slack without preloading the bond.
Step 8: Zero travel, start the test and record load against separation continuously.
Step 9: Peel at least half the bonded area (about 76 mm of bond, roughly 152 mm of crosshead travel); peel the full bond if the trace is erratic.
Step 10: Inspect both surfaces, record and photograph the failure mode along the bond, then calculate the results.
How to calculate average peel strength from the trace
D903 asks you to "draw the best average load line" through the peel portion of the chart and report that load per unit width. On a modern machine, that line is the mean load over a defined part of the trace. The standard leaves the window to the operator, so define it in your method and apply it identically to every specimen.
Reading the trace and choosing the window
Take-up and initial peak: the load rises as the folded tail straightens, often to a peak as the front starts, especially if adhesive bridged into the tail. This is not peel.
Peel region: the load settles into a band around a steady level. Smooth adhesives give a narrow band; tough, rubbery and filled adhesives give a saw-tooth stick-slip pattern.
Start the window after the initial peak, typically after the first 25 mm (1 in) of peel, and end it before the last 25 mm of bond or the end of the recorded peel.
Convert travel to peel distance: at 180°, peel distance = crosshead travel ÷ 2. A window from 25 to 76 mm of peel (50 to 152 mm of travel) always fits inside the minimum peel; longer is better.
Which average?
Mean load over the window (recommended): the closest digital equivalent of the best average load line, and what most software calls average peel load.
Mean of peaks and mean of troughs: useful for saw-tooth traces and required by some specifications. ISO 6133 describes methods for analysing multi-peak traces.
Never report the maximum as peel strength. The maximum is reported separately.
The calculation
Peel strength: P = F ÷ b, where F is the average load over the window and b is the measured width.
Units: N/mm (equal to kN/m), N/25 mm or lbf/in. D903 still prints kilograms per millimetre (pounds per inch), meaning kilogram-force: 1 kgf/mm = 9.807 N/mm.
Conversions: 1 lbf/in = 0.1751 N/mm; 1 N/mm = 5.710 lbf/in.
Tare: if you hung an alignment weight, zero with it hanging or correct the average for it.
Series: report each specimen and the arithmetic mean as the average value, with the maximum and minimum.
Worked example. A canvas strip is bonded to a 1.6 mm steel strip with a contact adhesive; the measured width is 25.0 mm. After take-up and an initial peak of 168 N, the trace settles into a stick-slip band between about 100 and 125 N. The window runs from 25 to 125 mm of peel (50 to 250 mm of crosshead travel), and the mean load over it is 112.5 N. P = 112.5 ÷ 25.0 = 4.50 N/mm, which is 4.50 kN/m, 112.5 N/25 mm, or 4.50 × 5.710 = 25.7 lbf/in (0.459 kgf/mm in the standard's legacy units).
Series example. Ten specimens give 4.50, 4.85, 4.12, 4.71, 4.33, 4.60, 3.98, 4.79, 4.41 and 4.71 N/mm. The mean is 45.00 ÷ 10 = 4.50 N/mm (25.7 lbf/in), minimum 3.98 and maximum 4.85 N/mm. The standard deviation is about 0.29 N/mm, a coefficient of variation of 6.4 %, which is good for peel. If the low specimen also failed adhesively at the steel while the others failed cohesively, that is a surface preparation problem, not scatter, and it belongs in the report.
Typical values
Treat these as orders of magnitude, not targets; peel strength depends on the adhesive and both adherends.
Pressure-sensitive tapes and labels peel at a fraction of 1 N/mm and are normally tested to ASTM D3330.
Contact cements and rubber-based adhesives bonding fabric, rubber or vinyl to metal or wood commonly fall around 1 to 10 N/mm (roughly 6 to 60 lbf/in).
When the substrate tears before the bond fails, the value is a lower bound on the bond; report it with the failure mode.
Precision and scatter
D903 has no interlaboratory precision and bias statement, because the round-robin resources were not available. Treat results as comparative within one lab, one specimen construction and one procedure. Coefficients of variation of 5 to 15 % are common in a well-run series, and more if the failure mode changes along the bond. Most scatter comes from bonding and alignment rather than the machine: surface preparation, coat weight, bond pressure, width, tail alignment and the averaging window. Ten specimens from at least two panels average that out.
Peel testing at high and low temperature
Many specifications require peel at service temperature, such as cold peel for automotive trim or hot peel for roofing and under-hood products.
Fit an environmental chamber around the grips; ours run from −80 to +280 °C. Condition the specimens to temperature and test inside the chamber.
Check the height: the specimen hangs about 200 mm from the lower grip, and the folded tail and upper grip need room above the bond. Use jaw faces rated for the temperature.
Size the chamber with our temperature chamber buyer's guide.
What to report
The standard and edition, and any agreed deviations.
Adhesive (type, maker, batch), both adherends (material, thickness, surface preparation) and any backing on the flexible member.
Bonding procedure, cure, conditioning, and test temperature and humidity.
Number of specimens, crosshead speed (305 mm/min), separation rate (152 mm/min) and the averaging window.
Each peel strength and the average, maximum and minimum, in N/mm or lbf/in, with the traces.
The type of failure for each specimen (adhesive, cohesive, substrate or mixed), ideally with photos.
Common ASTM D903 problems and how to fix them
Crosshead at 152 mm/min: that is the separation rate. Run the crosshead at 305 mm/min (12 in/min).
Averaging the whole trace: take-up and the initial peak are not peel. Average a defined window in the steady region, set in peel distance (travel ÷ 2).
Peeling too little: D903 requires at least half the bonded area.
Specimen swinging out of plane: the angle drops below 180° and the load drifts. Use an alignment plate or the minimum hanging weight.
Tail off-centre or twisted: one edge leads and the front tears diagonally. Centre and square the tail.
Tail stretches or breaks: back it with a non-extensible material or use a stronger adherend, and report it.
Slipping tail: a falling plateau or sudden drops. Switch to pneumatic or roller grips or change jaw faces.
Load cell too big: a 20 N peel on a 5 kN cell is 0.4 % of capacity, far outside the 15 to 85 % rule.
Testing too early: contact and solvent-borne adhesives gain strength for days. Condition 7 days unless the manufacturer says otherwise.
ASTM D903 vs. ISO 8510-2, D3330, D6862 and the T-peel test
ISO 8510-2: the international 180° peel test for flexible-to-rigid adhesive assemblies and the closest counterpart to D903, but with a different crosshead speed (100 mm/min) and specimen details, so values are not interchangeable. ISO 8510-1 is the 90° version; see our ISO 8510-1 page.
ASTM D3330: peel adhesion of pressure-sensitive tape from a standard steel panel at 300 mm/min. For tapes and labels, not bonded joints.
ASTM D6862: 90° peel on a sliding table fixture, for flexible members that would crease or yield if folded back 180°.
ASTM D1876: T-peel of two flexible adherends at 254 mm/min, averaged over 127 mm after the initial peak. See the D1876 complete guide.
ASTM D3167: floating roller peel of a thin metal adherend from a rigid one, for structural metal bonds too stiff to fold back.
ASTM D1781: climbing drum peel for sandwich facings; the result is peel torque per width.
ASTM D413 and ASTM D429: rubber-to-fabric and rubber-to-metal adhesion; see D413 vs. D429 explained.
ASTM F88: seal strength of flexible barrier materials, for heat seals rather than adhesive bonds.
180° peel or T-peel?
If one adherend is rigid, use D903, or D3167 or D6862 when the flexible member is too stiff to fold back. If both are flexible, D1876 is usually better, because the T-peel needs no rigid backing and both arms bend symmetrically. When a customer specifies D903 for two flexible adherends, test the stiffer one as the "rigid" member or bond it to a backing, and report what you did. The D1876 T-peel complete guide explains when the T geometry gives the more meaningful number.
Related adhesive tests
ASTM D1002: lap shear of metal bonds. See the D1002 lap shear complete guide and lap shear vs. block shear.
ASTM D905 and ASTM D4501: block shear of wood and rigid plastic bonds.
ASTM D897 and ASTM D2095: tensile (butt joint) strength of adhesives; ASTM D1062: cleavage of metal bonds.
Every adhesive method is on the adhesive testing page and every standard on the ASTM standards page.
Complete ASTM D903 equipment packages
Basic QC peel station
Mark-10 F105 motorized tester (305 mm/min within the standard speed range), or an F305 if the stand also runs higher-force tests
A low-capacity load cell sized so peel loads fall between 15 % and 85 % of capacity
Vise grip with an alignment plate for the rigid adherend and a roller grip for the tail, or a complete 180° peel fixture, with grip adapters for your frame
Advanced adhesive development lab
Galdabini 2.5 kN or 5 kN universal testing machine with full test-method software
Pneumatic grips with foot pedal for the tail and a vise or wedge grip with alignment plate for the rigid adherend
T-peel, 90° peel, floating roller and climbing drum fixtures from our peel fixtures range
Environmental chamber for −80 to +280 °C and a video extensometer or camera to record failure modes
ASTM D903 FAQ
What is ASTM D903?
The ASTM standard test method for peel or stripping strength of adhesive bonds. A 25 mm wide flexible strip bonded over 152 mm to a second strip is folded back and peeled at about 180°, and the average load per unit width is reported as peel strength.
What is the ASTM D903 test speed?
The moving grip travels at 305 mm/min (12 in/min), giving a separation (peel) rate of 152 mm/min (6 in/min). Setting the crosshead to 152 mm/min peels at half the specified rate.
What are the ASTM D903 specimen dimensions?
A flexible adherend 25 mm (1 in) wide by 305 mm (12 in) long, bonded over 152 mm (6 in) to a second adherend 25 mm wide by 203 mm (8 in) long, with adherends no more than 3 mm thick.
How many specimens does ASTM D903 require?
At least ten per adhesive. A specimen with an obvious flaw that puts it out of line can be discarded and replaced.
How is peel strength calculated in ASTM D903?
Average the load over the steady peel region (the standard's "best average load line"), excluding take-up and the initial peak, and divide by the measured width. Report each specimen in N/mm or lbf/in, plus the series mean, maximum and minimum.
How much of the bond must be peeled?
At least half the bonded area, about 76 mm (3 in) of the 152 mm bond, even if a steady value appears sooner. That takes roughly 152 mm of crosshead travel.
What is the difference between 180° peel and T-peel?
In a 180° peel (D903) a flexible strip is folded back and peeled from a rigid one at a fixed angle. In a T-peel (ASTM D1876) two flexible adherends are pulled apart in a T at 254 mm/min. See our D1876 complete guide.
Can I run ASTM D903 on a Mark-10 tester?
Yes. Every Mark-10 F-series frame reaches 305 mm/min: the F105, F305 and F505 within their standard range up to 330 mm/min, and the F755 and F1505 within 10 to 600 mm/min. Size the load cell so peel loads fall between 15 % and 85 % of capacity.
What grips do I need for ASTM D903?
A vise or wedge grip for the rigid adherend, a pneumatic or roller grip that clamps the folded tail evenly across its width, and an alignment plate or minimum hanging weight to keep the specimen in the grip plane.
Do I need an extensometer for ASTM D903?
No. Peel strength is force per width, and crosshead travel gives the separation. A camera or video extensometer helps record the failure mode and peel angle, especially inside a temperature chamber, but it is not required.
What conditioning does ASTM D903 specify?
7 days at 23 ± 1 °C and 50 ± 2 % RH, or until equilibrium, unless the adhesive manufacturer states a shorter period is enough.
Is ASTM D903 the same as ISO 8510-2?
No. Both are 180° peel tests of flexible-to-rigid bonds, but the speed and specimen details differ, so results are not interchangeable.
Related reading
Get a complete ASTM D903 system
Universal Grip supplies everything for ASTM D903 and the rest of the peel family: 180°, 90°, T-peel, floating roller and climbing drum peel fixtures, vise, wedge, pneumatic and roller grips, grip adapters, environmental chambers, video extensometers for documenting failure modes, and testing machines from a Mark-10 tensile tester to a full Galdabini universal testing machine. Tell us your adherends, expected peel loads and temperature range, and we will configure a compliant D903 system and quote it. Contact us.
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