Specification builder · Tier C
Flexural (bend) testing machine for three- and four-point bending of plastics and medical-device components (ISO 178, ASTM D790, ISO 9626)
A flexural (bend) testing machine pushes on a specimen resting on two supports and measures force against deflection to give flexural strength, modulus and stiffness. Drug and device testing labs, needle, catheter and plastics manufacturers and universities use it for ISO 178 / ASTM D790 tests on plastics, ISO 9626 needle tubing stiffness and breakage, and bending of catheter shafts and guidewires. A universal testing machine fitted with three- and four-point bend fixtures does the same job, so both a dedicated bend tester and a UTM-based set-up are offered here.
What this equipment will do
- Sample types: standard plastics bar specimens of resins and moulded parts (ISO 178, ASTM D790).
- Sample types: hypodermic needle tubing and cannulae, typically 18G to 30G (ISO 9626). (with the optional module)
- Sample types: catheter shafts, guidewires, tubing and small moulded device parts, on a short-span low-force fixture. (with the optional module)
- Three-point bending of plastics: flexural stress, strain, strength and modulus (ISO 178; ASTM D790 Procedures A and B).
- Four-point bending of plastics (ASTM D6272). (with the optional module)
- Needle tubing stiffness: deflection under a set force in three-point bending, pass/fail against the ISO 9626 table (ISO 9626 Annex B). (with the optional module)
- Needle tubing resistance to breakage: bending back and forth for the set number of cycles, break / no-break (ISO 9626 Annex C). (with the optional module)
- Guidewire fracture and flexing tests around rigid mandrels (ISO 11070). (with the optional module)
- Bending of catheter shafts, guidewires and polymer device parts in water or saline at 37 deg C. (with the optional module)
- Bending at controlled temperature from -40 to +150 deg C in an environmental chamber. (with the optional module)
- Direct mid-span deflection measurement, independent of crosshead travel, for more accurate modulus (transducer calibrated to ISO 9513). (with the optional module)
- Tensile and compression testing as well, by changing to tensile or compression fixtures (these fixtures are not part of this pack). (with the optional module)
Not covered: Needle sharpness and penetration force need the needle penetration tester (ISO 7864).; Needle-to-hub bond strength and catheter or tubing tensile strength need tensile grips on a universal testing machine (ISO 7864, ISO 10555-1); this pack supplies bending fixtures only.; Impact strength of plastics (Charpy or Izod, ISO 179 / ISO 180) needs a pendulum impact tester.; Bending fatigue over thousands or millions of load cycles needs the dynamic fatigue testing machine.
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Standards this specification draws on
- IEC 61010-1 Basic electrical safety standard for measurement, control and laboratory equipment, including the testing machine's controller.
- IEC 61326-1 EMC requirements for laboratory equipment so the load-cell signal is not disturbed and the machine does not disturb other instruments.
- ISO 178:2019 International three-point flexural test for plastics (specimen, span, speed, supports and modulus calculation) the machine must be able to run.
- ASTM D790-25 ASTM three-point flexural test for unreinforced and reinforced plastics (Procedures A and B), widely quoted by resin and device-part suppliers.
- ASTM D6272-25 Four-point flexural test for plastics; needs the four-point loading attachment.
- ISO 9626:2016 Stainless steel needle tubing standard; Annex B stiffness (three-point bend) and Annex C resistance-to-breakage tests are done on this equipment.
- ISO 11070:2014 Intravascular introducers, dilators and guidewires (with Amd 1:2018); includes guidewire fracture and flexing tests the lab may run with bending fixtures and mandrels.
- ISO 7500-1:2018 Calibration and verification of the force-measuring system of static testing machines; sets the accuracy class of each load cell.
- ASTM E4-24 US practice for force verification of testing machines, accepted as an alternative to ISO 7500-1.
- ISO 9513:2012 Calibration of extensometers and deflection transducers used to measure specimen deflection.
- ISO/IEC 17025:2017 Accreditation standard for testing and calibration labs; requires calibrated, traceable equipment and controlled records.
- 21 CFR Part 11 / EU GMP Annex 11 Rules for electronic records and signatures when test results are used for batch release or regulatory decisions.
Common mistakes in tenders for this equipment
- Specifying a dedicated 'flexural tester' only, which shuts out universal testing machine makers whose machine with bend fixtures does the same tests; allow either.
- Copying one maker's exact capacity, speed range, test space or load-cell list so only that brand complies; state minimum needs with 'not less than' instead.
- Ordering one large load cell for a lab that tests needles and guidewires at a few newtons, so small-force results are inaccurate.
- Leaving out the ISO 9626 needle stiffness fixture, breakage apparatus and catheter small-span fixtures; the machine then cannot run the device tests it was bought for.
- Accepting a factory calibration sheet without ISO/IEC 17025 accreditation, measurement uncertainty and calibration of every load cell and the deflection transducer.
- Asking for DRAP medical-device registration or ISO 13485 for the tester; it is a laboratory instrument and these demands only confuse bidders.
- Not fixing the yearly calibration and service price after warranty, so recalibration costs rise sharply once the supplier is the only one familiar with the machine.