Standard 25 mm
Pneumatic Vice Action Grip
Constant, gentle air pressure across a flat face — enough to hold a thin-wall cannula without collapsing it, which a serrated wedge would.
SpecificationsTesting standard
ISO 7864
Sterile hypodermic needles for single use — Requirements and test methods
Written and technically reviewed by Dak System Inc. engineeringLast reviewed
ISO 7864 sets requirements and test methods for sterile single-use hypodermic needles. The most consequential is the cannula-to-hub bond: the joint is loaded axially until it separates, because a cannula that pulls out of its hub during withdrawal is a serious adverse event rather than a quality defect.
At a glance
- Test type
- Tensile — the specimen is pulled apart
- Published by
- ISO
- Runs on
- Series 7200 and Series 9000
What the test does
A finished needle is subjected to several mechanical checks. The bond between the cannula and its hub is loaded axially until it separates, giving the pull-out force. The cannula is loaded transversely to check stiffness and resistance to breakage, the point is examined and tested for penetration performance, and the hub is checked for correct fit to a conical fitting.
What it measures, and why it matters
The most consequential figure is the cannula-to-hub bond strength: a needle whose cannula pulls out of its hub during withdrawal leaves the cannula in the patient, which is a serious adverse event rather than a quality defect. Penetration force describes how sharp the point is, and it rises as a grind degrades or a coating is missing. Stiffness governs whether a fine-gauge needle can be inserted without bending.
The bond figure is checked against a limit that scales with gauge, and that scaling is the part most often misread. A fine needle is not permitted a weaker bond because it is less important; it is permitted one because the bonded annulus is physically smaller, and the limit reflects the geometry rather than the risk. The risk is identical at every gauge, which is why the acceptance limits are absolute rather than proportional to what a manufacturer can achieve.
The needle as supplied
- Specimen
- Finished sterile needles from unopened packs
- Gauge and length
- RecordedBond strength requirements scale with cannula diameter — a fine needle is held by a much smaller bonded area, and the acceptance limits reflect that.
- Handling
- The point is not touchedContact blunts it measurably, and penetration force is one of the reported quantities.
- Cannula grip
- Must hold without crushingA thin-wall tube collapses under a serrated jaw, the bond is then loaded unevenly, and the pull-out force reads low.
Test speed
- Bond pull-out
- Constant axial rate to separation
- Penetration
- Constant slow rate into a specified substrate
- Forces
- Very smallResolution at the bottom of the load cell's range decides whether the test means anything.
What comes out
Cannula-to-hub bond strength—
Peak axial force to separate the cannula from the hub, N
Compared against a limit that scales with gauge. It is a pass-or-fail against the specification rather than a material property.
Penetration force—
Force to drive the point through the specified substrate, N
Rises as a grind degrades or a coating is missing, which makes it a good process monitor as well as a product requirement.
How the bond test runs
- 01Take needles from unopened packs and record gauge, length and batch.
- 02Handle by the hub so the point is never touched.
- 03Grip the hub in a fixture that holds it without distorting it.
- 04Grip the cannula in soft or profiled jaws that will not crush the tube.
- 05Pull axially at the constant specified rate.
- 06Record the peak force at separation.
- 07Inspect whether the cannula pulled out cleanly or the hub fractured.
- 08Run the stiffness, penetration and hub-fit procedures as the specification requires.
Crushing the cannula is the classic fault. The tube deforms, the adhesive bond is then loaded unevenly along its length, and the recorded pull-out force is lower than the bond can actually carry — a false failure that looks like a manufacturing problem.
Watch the test
Grips and fixtures for this method
TJ-139
Attachment For Needle Piercing Force Measurement
A fixture built for needle work, holding the hub while force is applied along the cannula axis.
SpecificationsWhat the report has to contain
- Reference to ISO 7864
- Needle identification, GAUGE, length and batch
- How the cannula and hub were gripped
- Rate of loading
- Cannula-to-hub bond strength, against the limit for that gauge
- Whether separation was a clean pull-out or a hub fracture
- Penetration force where measured, and the substrate used
- Stiffness and hub-fit results where run
- Number of needles tested
What the machine must be capable of
Very small forces and short travels, so resolution at the bottom of the load cell's range decides whether the test means anything. For pull-out the hub must be held without gripping the cannula, and the cannula gripped without crushing it — a thin-wall tube collapses under a serrated jaw. Penetration testing needs a controlled substrate and a constant, slow rate.
The cell must resolve a few newtons cleanly and the fixture must solve two opposite problems at once: hold a hub without distorting a moulded plastic taper, and hold a thin-wall stainless cannula without collapsing it. Soft-faced or profiled jaws are the practical answer to the second. Penetration testing adds a third requirement, a substrate presented consistently, since penetration force is as much a property of what is being pierced as of the point.
What goes wrong in practice
Crushing the cannula in the grip is the classic fault: the tube deforms, the bond is loaded unevenly, and the pull-out force reads low. Touching the point before a penetration test blunts it. And testing a needle from a pack that has been opened and re-closed introduces handling damage the packaging exists to prevent.
Aside from crushing the cannula, two faults recur. A hub gripped at the wrong point can flex enough that the bond is peeled progressively rather than loaded in tension, which reads low. And needles taken from a pack that has been opened and resealed frequently show blunted points and occasionally bent cannulae, so the pack condition is recorded as part of the specimen history rather than assumed.
The needle and syringe pair
| ISO 7864 | ISO 7886-1 | ISO 9626 | |
|---|---|---|---|
| Covers | The finished needle | The finished syringe | The stainless steel tubing |
| Key mechanical test | Cannula-to-hub bond | Plunger force | Tube stiffness and resistance to breakage |
| Specimen | As supplied | As supplied | Tubing before assembly |
The three sit in sequence: ISO 9626 qualifies the tubing, ISO 7864 the assembled needle, ISO 7886-1 the syringe it fits. A failure at any level can look like a failure at another, which is why they are separate documents.
Questions we are asked about this test
What is ISO 7864?
It is the international standard for sterile single-use hypodermic needles, setting requirements and test methods for the cannula-to-hub bond, cannula stiffness and resistance to breakage, point penetration performance and hub fit.
Why is the cannula-to-hub bond the most important test?
Because of what its failure means. A needle whose cannula separates from its hub during withdrawal leaves the cannula in the patient — an adverse event requiring intervention rather than a quality complaint. Every other requirement in the standard is about performance; this one is about a specific serious harm.
Why do bond strength requirements depend on gauge?
Because a finer cannula is held by a much smaller bonded area. A 30-gauge needle simply cannot develop the bond force a 18-gauge one can, so a single limit would either be unachievable for fine needles or meaningless for coarse ones. The acceptance limits scale accordingly.
Why did my pull-out force come out low?
Most often because the cannula was crushed in the grip. A thin-wall tube deforms under a serrated jaw, the bond is then loaded unevenly along its length rather than uniformly, and it lets go early. Soft or profiled jaws that hold without distorting the tube remove the problem.
Why must the point not be touched?
Because contact blunts it, and penetration force is one of the reported quantities. A needle handled at the point before testing gives a higher penetration force for a reason that has nothing to do with how it was manufactured — and blunting is not visible without magnification.
Why does a needle bend during insertion?
Usually gauge rather than quality. A fine cannula is inherently flexible, and the stiffness requirement in the standard sets a floor rather than promising rigidity. A needle that bends well inside its gauge's expectation points instead at the tubing, which is qualified separately under ISO 9626 — that is the document to reach for when stiffness is the complaint.
Can penetration force be compared between laboratories?
Only where the substrate is the same. Penetration force is as much a property of what is being pierced as of the point, so a result on one medium does not transfer to another. Within a laboratory it is a good process monitor — a rising force across a production run is a grind degrading — but between laboratories it needs the substrate stated and matched.
Running ISO 7864 on the Series 7200 and Series 9000
Dak verifies against whichever standard the method names, and where a class applies our frames sit a class tighter than it asks.
| The method asks for | Dak supplies | |
|---|---|---|
| Capacity | Very low. Bond strength limits scale with cannula gauge, so resolution decides whether the test discriminates. | Load cells from 1 kg to 60 ton on the Series 7200, and 0.5 to 100 kN on the Series 9000 |
| Force accuracy | ISO 7500-1 Class 1 | ISO 7500-1 Class 0.5 — a class tighter than the method asks |
| Gripping | A hub holder and soft or profiled jaws that grip the cannula without collapsing the tube. | Wedge, vice-action, pneumatic and hydraulic grips, built to the specimen |
| Environment | Ambient, from unopened sterile packs. | 3009 series chambers, −150 °C to +400 °C — temperature only |
This page describes the method as practised. The governing text is the current edition from the issuing body. Tell us what you are testing and we will answer with the machine, the fixture and a quotation.