ISO 178
Flexural Properties of Plastics: Three-Point Bending

Universal Grip ISO 178 three-point flexure fixture for plastics

Downloads: ISO 178 Three-Point Flexure Fixture for Plastics – Universal Grip Data Sheet (PDF)

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

ISO 178 is the international standard for the flexural properties of rigid and semi-rigid plastics. A bar supported near its ends is loaded at mid-span at a constant rate until it breaks or reaches 5 % outer-fibre strain, and the force-deflection curve gives the flexural strength, the flexural modulus, the stress at a conventional deflection and the strain at those points. It is the ISO twin of ASTM D790, the companion to the tensile test in ISO 527-1, and the test that produces the flexural modulus printed on almost every European and Asian plastics datasheet.

This guide covers the current edition, ISO 178:2019, and the revision now in enquiry; the preferred 80 × 10 × 4 mm bar and the alternative widths; the 16h span rule and the R5 and R2 radii with their tolerances; the full speed table and the strain-rate arithmetic that leads to 2 mm/min; Methods A and B and the four test types that decide whether crosshead deflection is allowed; the 0.05 to 0.25 % chord modulus, the 3.5 % conventional-deflection stress and the 5 % stop; every formula with a checked worked example; the common errors and their size; a numeric comparison with ASTM D790; and the fixtures, deflectometers and machines Universal Grip supplies for the test. The plastics testing page gives the lab overview and the ISO standards hub lists every ISO method we equip.

In this guide: What ISO 178 Measures and Where It Applies · Editions: 2010, 2019 and the Revision in Enquiry · Specimen: the 80 × 10 × 4 mm Bar and the Alternatives · Span, Radii and Fixture Requirements · Test Types I–IV and Deflection Measurement · Test Speed: the Table, the Formula and Methods A and B · Conditioning, Procedure and End of Test · Formulas and a Worked Example · Common Errors and How Large They Are · ISO 178 vs ASTM D790: the Numbers · Equipment for ISO 178: Fixture, Deflectometer, Machine · FAQ

What ISO 178 Measures and Where It Applies

ISO 178 applies to thermoplastic and thermosetting moulding compounds, filled and reinforced, and to rigid sheet, tested as a freely supported beam in three-point bending. It is a materials-testing and quality-control method rather than a design method: the stresses it reports assume a linear-elastic beam, which real plastics are only at small strain, so the numbers are comparative. Rigid cellular materials are tested to ISO 1209 and long-fibre laminates to ISO 14125, which keeps the same geometry but changes the span-to-thickness ratios. The properties defined are:

Flexural stress σf: the nominal outer-surface stress at mid-span, from the elastic beam formula.
Flexural strain εf: the nominal outer-surface strain at mid-span, from the deflection.
Flexural strength σfM: the maximum stress reached during the test, if it occurs before 5 % strain.
Stress at break σfB: the stress at rupture, if rupture occurs before 5 % strain.
Stress at conventional deflection σfC: the stress at a deflection of 1.5 times the thickness, which is 3.5 % strain at a 16h span, reported for materials that neither break nor reach a maximum before that point.
Flexural modulus Ef: the chord slope of the stress-strain curve between 0.05 % and 0.25 % strain, the same window as the tensile modulus in ISO 527.
Strains at strength and at break, reported alongside the stresses, and the 95 % confidence statistics per ISO 2602.

The 2019 edition introduced four test types that decide how accurate the deflection measurement must be: Type I for strength only, Type II for strength plus strains above 1 %, Type III for a repeatable modulus and Type IV for an accurate modulus. The type you declare sets the deflection-measurement class, which is the single thing most labs get wrong, so it is covered in its own section below.

Editions: 2010, 2019 and the Revision in Enquiry

ISO 178:2019 is the sixth edition and the current one. It replaced ISO 178:2010 with its 2013 amendment, and the changes are practical rather than cosmetic: the calibration requirements now depend on the declared test type, the deflectometer was written in as the instrument for Types III and IV, the compliance-correction procedure for crosshead deflection (Annex C, with a steel reference bar) was reinstated, and a new Annex D explains why a correctly measured flexural modulus should be close to the tensile modulus of the same material. JIS K 7171 is the technically identical Japanese adoption.

A seventh edition, ISO/DIS 178, went through its enquiry vote in mid-2026 and will replace the 2019 text when it is published. Nothing in the draft changes the specimen, span, radii or speeds that this guide describes, but a lab certifying to ISO 178 should watch for the publication date and update its designation form. Several equipment pages still cite the 2010 edition, and a few quote values from the 1993 and 2001 texts; where this guide gives a number it is the 2019 value.

Specimen: the 80 × 10 × 4 mm Bar and the Alternatives

The preferred specimen is a rectangular bar 80 ± 2 mm long, 10.0 ± 0.2 mm wide and 4.0 ± 0.2 mm thick. It is the centre section of the ISO 20753 type A1 multipurpose dumbbell used for ISO 527-2, so a single moulding gives both the tensile and the flexural specimen, or it is injection moulded directly to ISO 294-1 or ISO 10724-1, compression moulded to ISO 293 or ISO 295, or machined from sheet to ISO 2818. Within the central third of the length the thickness must not vary by more than 2 % and the width by more than 3 % of the mean, and a specimen whose mean thickness differs from the batch mean by more than 2 % is replaced.

When the material cannot be made 4 mm thick, the standard keeps the width proportional to the thickness so that the beam stays beam-like. The widths, all ± 0.5 mm, are:

Thickness 1 to 3 mm: width 25.0 mm (R2 supports are used at 3 mm and below).
Thickness over 3 to 5 mm: width 10.0 mm, the preferred bar.
Thickness over 5 to 10 mm: width 15.0 mm.
Thickness over 10 to 20 mm: width 20.0 mm.
Thickness over 20 to 35 mm: width 35.0 mm.
Thickness over 35 to 50 mm: width 50.0 mm; materials with coarse fillers use at least 30 mm width at any thickness.

Width is measured to 0.1 mm and thickness to 0.01 mm at mid-length with a micrometer meeting ISO 16012; the thickness matters more than anything else in the test because stress goes as 1/h² and modulus, through the deflection formula, as 1/h³. At least five specimens are tested per direction, and materials whose properties differ by more than 20 % between the two principal directions of a sheet are tested in both. Any specimen that breaks outside the central third of the span is discarded and replaced.

Span, Radii and Fixture Requirements

The support span is L = 16h ± 1 mm, which is 64 mm for the 4 mm bar, measured to 0.5 % (0.3 mm at 64 mm). Three exceptions exist: thick or unidirectionally reinforced bars whose shear strength is low relative to their tensile strength may use spans up to 60 times the thickness so that they fail in tension rather than shear; very thin bars of materials with a modulus below 700 MPa may use 8h; and flexible materials below 700 MPa may use 32h. If you need a long span on a laminate you are usually in ISO 14125 territory, which sets the ratio by material class.

Loading edge: a cylindrical surface of radius R1 = 5.0 mm, longer than the specimen width.
Supports: cylindrical surfaces of radius R2 = 5.0 ± 0.2 mm for thickness above 3 mm and 2.0 ± 0.2 mm for thickness of 3 mm and below. The small radius on thin bars keeps the contact from spanning a significant fraction of the thickness.
Parallelism: the supports and the loading edge are parallel to each other within ± 0.2 mm across the specimen width, and the loading edge sits midway between the supports.
Force measurement: ISO 7500-1 class 1 (± 1 % of reading) for all test types.
Deflection measurement: depends on the test type, below.

The radii are not a detail. A 5 mm loading edge on a 4 mm bar indents soft and semi-crystalline plastics measurably at the modulus loads, which is one reason the standard limits crosshead-based modulus to the lower test types, and worn or chipped radii change both the contact stress and the effective span. Hardened, ground radii that are checked periodically are a legitimate fixture specification, not a sales point.

Test Types I–IV and Deflection Measurement

The deflection s is the mid-span displacement of the bar relative to the supports. The 2019 edition ties the way it may be measured to the purpose of the test:

Type I (strength only): crosshead displacement is acceptable; the deflection is used only to define the end of the test and the conventional deflection.
Type II (strength and strains above 1 %): crosshead displacement is acceptable; the strains reported are large enough that machine compliance is a small fraction of them.
Type III (repeatable modulus): an ISO 9513 class 2 deflection measurement (± 2 % of reading, which is ± 6.8 µm at the 0.34 mm span of the modulus window on the preferred bar), and if the crosshead is used its displacement must be compliance-corrected per Annex C by calibrating the load train against a stiff steel reference bar and subtracting the machine deflection at each force.
Type IV (accurate modulus): an ISO 9513 class 1 measurement (± 1 %, ± 3.4 µm); in practice a deflectometer, a contacting transducer that rides on the underside of the bar at mid-span, or a non-contact video or laser system reading the bar directly.

On the preferred bar the modulus window runs from a deflection of 0.085 mm at 0.05 % strain to 0.427 mm at 0.25 %, a span of only 0.34 mm, which is why the class of the deflection measurement decides whether the modulus is real. Crosshead displacement on a benchtop frame with a 5 kN load cell and a clevis-mounted fixture can include 0.05 to 0.15 mm of load-train compliance at the modulus loads, which would understate the modulus by 15 to 45 % if not corrected. The Universal Grip deflectometers and extensometers and video extensometers are the instruments that satisfy Types III and IV directly.

Test Speed: the Table, the Formula and Methods A and B

The crosshead speeds in Table 1 are 1, 2, 5 and 10 mm/min with ± 20 % tolerance and 20, 50, 100, 200 and 500 mm/min with ± 10 %; 1 mm/min is reserved for bars 1 to 3.5 mm thick. The speed is chosen to give a target outer-fibre strain rate r (in %/min) from the geometry: v = r · L² / (600 · h) with v in mm/min and L and h in mm. For the modulus the target is about 1 %/min, which on the 64 × 4 bar gives v = 1 × 64² / (600 × 4) = 1.7 mm/min, so the nearest table speed, 2 mm/min, is used. For strength the standard offers two routes:

Method A: one speed for the whole test, normally 2 mm/min on the preferred bar. Simple, slow (a 5 % strain test takes about 4 minutes), and the method most QC labs use because it needs no speed change.
Method B: 2 mm/min through the modulus window, then a switch to the speed that gives about 5 %/min (10 mm/min on the preferred bar) for materials that break without a stress maximum, or about 50 %/min (100 mm/min) for everything else. The test takes under a minute after the modulus and the strength is measured at a rate closer to the tensile test.

The speed and method are part of the result designation and must be reported, because flexural strength of a viscoelastic material rises with rate: a polypropylene bar tested at 100 mm/min reads several percent higher than at 2 mm/min. Before the test a small preload seats the bar: for modulus it must not exceed a stress of 5 × 10⁻⁴ times the expected modulus (0.05 % prestrain, the start of the window), for strength 1 % of the expected strength, applied at 1 mm/min, and the test starts within a minute of reaching it.

Conditioning, Procedure and End of Test

Specimens are conditioned and tested in the ISO 291 standard atmosphere of 23 ± 2 °C and 50 ± 10 % relative humidity unless the material standard says otherwise; humidity conditioning may be omitted for materials that are insensitive to it, and polyamides follow their own accelerated conditioning. The procedure is then:

Measure width to 0.1 mm and thickness to 0.01 mm at mid-length; reject specimens outside the 2 %/3 % uniformity rules.
Set the span to 16h ± 1 mm, verify it to 0.5 %, and check that the loading edge is centred and parallel to the supports.
Place the bar symmetrically on the supports with its long axis perpendicular to them; for moulded bars the standard says which face goes down so that the moulding skin, not a machined face, is in tension when that matters to the comparison.
Apply the preload at 1 mm/min, zero the deflection, and start the test at the Method A or B speed within one minute.
Record force and deflection to rupture or to 5 % strain, whichever comes first; on the preferred bar 5 % strain is a deflection of 8.5 mm.
Record the deflection at any stress maximum and at break, and if neither occurs before 1.5h (6.0 mm on a 4 mm bar) record the stress at that conventional deflection.

The 5 % limit is a stop, not a reporting point: a material that is still rising at 5 % strain is reported as having no flexural strength in the sense of the standard, and the stress at 3.5 % (the conventional deflection) is its comparative value. A specimen that breaks outside the central third of the span is replaced.

Formulas and a Worked Example

For a bar of width b and thickness h on a span L, with force F and mid-span deflection s:

Flexural stress: σf = 3 F L / (2 b h²), in MPa with F in N and dimensions in mm.
Flexural strain: εf = 6 s h / L², as a ratio, or 600 s h / L² in percent.
Deflection for a given strain: s = εf L² / (6 h); on the preferred bar s = 0.085 mm at 0.05 % and 0.427 mm at 0.25 %.
Flexural modulus: Ef = (σf2 − σf1) / (εf2 − εf1) between εf1 = 0.0005 and εf2 = 0.0025, or the slope of a least-squares line through the data in that interval.
Conventional deflection: sC = 1.5 h, which at L = 16h is εfC = 6 × 1.5h × h / (256 h²) = 3.5 %.

There is no large-deflection correction in ISO 178; the bracketed correction some pages quote is ASTM D790's. A worked example on a glass-filled polyamide bar measured at 10.0 × 4.0 mm on a 64 mm span: the forces at the two modulus deflections are 8.0 N at 0.085 mm and 40.0 N at 0.427 mm. The stress factor is 3 × 64 / (2 × 10 × 16) = 0.600 MPa per newton, so σf1 = 4.8 MPa and σf2 = 24.0 MPa, and Ef = (24.0 − 4.8) / (0.0025 − 0.0005) = 19.2 / 0.002 = 9,600 MPa. The bar reaches a maximum force of 250 N at a deflection of 5.0 mm before breaking, so σfM = 0.600 × 250 = 150 MPa at a strain of 600 × 5.0 × 4 / 4096 = 2.9 %. Had it not broken, the stress at 6.0 mm would have been reported as σfC, and the test would have stopped at 8.5 mm. Stresses and modulus are reported to three significant figures, strains to two, with the mean, standard deviation and 95 % confidence interval of the five specimens.

Common Errors and How Large They Are

Thickness measured once, or to 0.1 mm. A 0.1 mm error on a 4 mm bar is 2.5 % of thickness, which is 5 % on stress and 7.5 % on modulus, because stress goes as 1/h² and modulus, via the deflection formula, as 1/h³. Three readings to 0.01 mm cost nothing.
Modulus from uncorrected crosshead displacement. Load-train compliance of 0.05 to 0.15 mm inside a 0.34 mm window understates the modulus by 15 to 45 %. Use a deflectometer or run the Annex C correction.
Wrong support radius on thin bars. R5 supports on a 2 mm sheet specimen put the contact across a quarter of the thickness; the standard requires R2 at 3 mm and below.
Span set from a stale scale or the wrong face of the support. 1 mm on 64 mm is 1.6 % on stress and about 5 % on modulus (L³ in the deflection relation). Set 16h ± 1 mm and verify to 0.3 mm.
Strength and conventional-deflection stress mixed up. σfC at 3.5 % strain is reported only when there is no maximum before it, and it is not a strength; datasheets that list it as 'flexural strength' overstate ductile materials.
Preload above the window. A preload that reaches 0.1 % strain deletes half the modulus interval and biases Ef upward.
Method and speed not reported. Method A at 2 mm/min and Method B at 100 mm/min give different strengths on the same compound; the designation must say which.
Bar not centred or not perpendicular. A 2 mm offset of the loading edge changes the bending moment at the contact by 6 % and moves the fracture out of the central third, which invalidates the specimen.
ISO and ASTM bars run on one fixture at one span. The ISO 4 mm bar needs 64 mm; the ASTM 3.2 mm bar needs 51.2 mm; neither result transfers to the other standard.

ISO 178 vs ASTM D790: the Numbers

ASTM D790 is the same three-point test on a different bar, and both standards say the results are not interchangeable. The differences that move the numbers:

Specimen: ISO 80 × 10 × 4 mm; ASTM 127 × 12.7 × 3.2 mm (5 × 0.5 × 0.125 in).
Span: both 16 times the thickness, so ISO 64 mm and ASTM 51.2 mm; ASTM also lists 32:1, 40:1 and 60:1 for composites, ISO lists 8h, 32h and 60h exceptions.
Radii: both R5 on the loading nose and supports; ISO switches to R2 supports at 3 mm and below.
Speed: both target 1 %/min outer-fibre strain for the modulus, which is 2 mm/min on the ISO bar and 1.37 mm/min (Procedure A, Z = 0.01 min⁻¹) on the ASTM bar; ASTM Procedure B at 0.10 min⁻¹ is 13.7 mm/min, ISO Method B is 10 or 100 mm/min.
Modulus: ISO chord or regression between 0.05 and 0.25 % strain; ASTM tangent to the initial linear portion, with secant and chord as options. On the same material the two definitions differ by a few percent on a linear compound and more on a semi-crystalline one.
Deflection measurement: ISO requires class 2 or class 1 instruments or compliance correction for modulus (Types III and IV); ASTM allows crosshead deflection with compliance correction recommended but not required.
End of test: both stop at 5 % strain; ISO additionally reports the stress at the 3.5 % conventional deflection; ASTM applies a large-deflection stress correction above 10 % of span deflection that ISO does not have.
Specimens: ISO at least five per direction; ASTM at least five.
Conditioning: ISO 291 and ASTM D618 both at 23 °C / 50 % RH; ASTM states a 40 hour minimum explicitly.

Round-robin data in the ISO 178 precision annex puts lab-to-lab reproducibility on the modulus of a polycarbonate at roughly 5 % of the mean even when every lab follows the standard, so a difference of that size between an ISO and an ASTM value on the same compound is noise, not information. A lab supplying both markets moulds both bars and runs both tests on one fixture with two span settings.

Equipment for ISO 178: Fixture, Deflectometer, Machine

Three-point flexure fixture

The Universal Grip ISO 178 three-point flexure fixture, part UGC-ISO178-BF, is built to the geometry above: an R5 loading edge applies force at mid-span while two R5 supports slide along a beam with an engraved millimetre scale, and R2 supports are available for bars of 3 mm and below. The scale is symmetric about the centreline so the span is set and the bar centred in one reading, the loading edge and base have quick-release pin connections, the loading edges are hardened steel on an aluminium and steel support beam, and the fixture comes with clevis or threaded adapters for your frame. Capacity is 5 kN standard, higher on request, and the span adjusts along the graduated beam over approximately 0 to 200 mm, which covers 64 mm for ISO, 51.2 mm for ASTM and the 32h and 60h exceptions on thin bars. Specify specimen dimensions, span range, support radius and machine connection when ordering. The bend testing fixtures page and the small bend fixture cover the other spans, four-point configurations and the ISO 14125 and ISO 14130 composite fixtures.

Capacity

Flexural loads on the preferred bar are small: the force at a given stress is F = 2 σ b h² / (3 L), so even a 300 MPa glass-filled compound needs only 2 × 300 × 10 × 16 / (3 × 64) = 500 N, and most unfilled thermoplastics break below 200 N. A 5 kN fixture therefore has ten times headroom, and the load cell matters more than the frame: a 1 or 2 kN cell keeps the modulus forces (8 to 40 N in the example) inside the class 1 range of the cell. The 5 kN, 10 kN and 25 kN benchtop machines on our 5 kN UTM, 10 kN UTM and 25 kN UTM pages run the two-speed Method B sequence and the 0.05–0.25 % regression, and a Mark-10 tensile tester with a compression-rated fixture adapter handles Type I and II strength tests on unfilled materials.

Deflection measurement

Types III and IV: a deflectometer or transducer reading the underside of the bar at mid-span, or a class 1 video extensometer tracking a target on the bar, from the extensometers page; the guided three-point video below shows a deflectometer in use.
Types I and II: crosshead displacement, with the Annex C compliance correction if a modulus is also wanted from the same test.
Elevated and reduced temperature: environmental chambers from −70 to +250 °C with a fixture and transducer rated for the chamber; flexural modulus of most thermoplastics halves between 23 °C and the heat-deflection region.

Specimen preparation

ISO 178 bars are moulded, not die-cut, but sheet materials are machined to ISO 2818 and thin sheet specimens for the 25 mm width class can be cut cleanly on a die press with a straight-edge die. Edges must be free of notches and the moulded skin kept where the standard puts it in tension. The plastics page lists the moulds and cutters for the ISO 20753 multipurpose bar from which the preferred specimen is taken.

ISO 178 FAQ

What is ISO 178?

The international standard for determining the flexural properties of rigid and semi-rigid plastics by three-point bending. A bar, preferably 80 × 10 × 4 mm, is loaded at mid-span on a 64 mm span until it breaks or reaches 5 % strain, giving flexural strength, flexural modulus, stress at a conventional deflection and the corresponding strains. The current edition is ISO 178:2019; a seventh edition is in enquiry.

What specimen size does ISO 178 use?

80 ± 2 mm long, 10.0 ± 0.2 mm wide and 4.0 ± 0.2 mm thick, taken from the centre of an ISO 20753 type A1 multipurpose bar or moulded directly. Other thicknesses use proportional widths: 25 mm for 1 to 3 mm, 15 mm for 5 to 10 mm, 20 mm for 10 to 20 mm, 35 mm for 20 to 35 mm and 50 mm for 35 to 50 mm. At least five specimens are tested.

What is the span in ISO 178?

16 times the specimen thickness, ± 1 mm, so 64 mm for the 4 mm bar, measured to 0.5 %. Exceptions are 8h for very thin low-modulus bars, 32h for flexible materials below 700 MPa and up to 60h for thick or unidirectionally reinforced bars that would otherwise fail in shear.

What radii do the ISO 178 loading edge and supports have?

The loading edge is a 5.0 mm radius cylinder. The supports are 5.0 ± 0.2 mm radius for specimens thicker than 3 mm and 2.0 ± 0.2 mm radius for specimens 3 mm thick and below. All three must be parallel within ± 0.2 mm across the specimen width.

What is the test speed in ISO 178?

Table 1 offers 1, 2, 5 and 10 mm/min (± 20 %) and 20, 50, 100, 200 and 500 mm/min (± 10 %). The speed comes from v = r L² / (600 h) for a target strain rate r; for the modulus the target is about 1 %/min, which is 1.7 mm/min on the 64 × 4 bar, rounded to the 2 mm/min table value. Method A keeps one speed; Method B switches after the modulus to 10 or 100 mm/min.

How is flexural modulus calculated in ISO 178?

Ef = (σf2 − σf1) ÷ (εf2 − εf1) between 0.05 % and 0.25 % flexural strain, as a chord or a least-squares slope, with σf = 3FL/(2bh²) and εf = 6sh/L². On the preferred bar the window is a deflection of 0.085 to 0.427 mm, which is why a class 1 or class 2 deflection measurement is required for test types III and IV.

What is the conventional deflection in ISO 178?

A deflection of 1.5 times the specimen thickness, 6.0 mm on a 4 mm bar, which corresponds to 3.5 % outer-fibre strain at a 16h span. If the specimen has neither broken nor reached a stress maximum by then, the stress at the conventional deflection σfC is reported in place of a flexural strength. The test itself stops at 5 % strain, 8.5 mm on the preferred bar.

What are test types I to IV in ISO 178?

Categories introduced in 2019 that set the deflection-measurement requirement: Type I strength only and Type II strength with strains above 1 % may use crosshead displacement; Type III repeatable modulus needs an ISO 9513 class 2 measurement or compliance-corrected crosshead per Annex C; Type IV accurate modulus needs class 1, in practice a deflectometer or video system.

What is the difference between ISO 178 and ASTM D790?

Both are 16:1 three-point bend tests with R5 radii stopped at 5 % strain, but ISO uses an 80 × 10 × 4 mm bar on a 64 mm span at 2 mm/min with a 0.05–0.25 % chord modulus and a 3.5 % conventional-deflection stress, while ASTM D790 uses a 127 × 12.7 × 3.2 mm bar on a 51.2 mm span at 1.37 mm/min with a tangent modulus and a large-deflection correction. Results are not interchangeable.

What preload is allowed in ISO 178?

For modulus, a stress no higher than 5 × 10⁻⁴ times the expected modulus, which keeps the prestrain below the 0.05 % start of the window; for strength, no more than 1 % of the expected strength. The preload is applied at 1 mm/min and the test starts within one minute.

What machine capacity is needed for ISO 178?

Very little: the force on the preferred bar is F = 2σbh²/(3L), so 300 MPa needs 500 N and most unfilled plastics break below 200 N. A 5 kN fixture on a 5 to 25 kN benchtop frame with a 1 or 2 kN load cell is the usual setup; capacity only matters for wide or thick composite bars.

Which fixture does Universal Grip supply for ISO 178?

The UGC-ISO178-BF three-point flexure fixture: R5 loading edge, R5 supports with R2 supports available, hardened steel edges, supports sliding on a graduated beam with a symmetric scale for span setting over about 0 to 200 mm, quick-release pins, 5 kN standard capacity and clevis or threaded adapters to suit the frame.

Need a three-point flexure fixture, deflectometer or a complete bend-testing system for ISO 178? Contact Universal Grip with your specimen size, span range and machine connection and we will quote the right setup.

Literature

Pricing and Availability

ISO 178 Flexural Properties of Plastics: Three-Point Bending