Neometrix / Materials Testing Machines / Universal Testing Machine / NMX-UTM-101

NMX-UTM-101 · ENGINEERED-TO-ORDER CLASS — DUTY · FRAME AND HYDRAULICS · GRIPS AND MEASUREMENT · CONTROL AND GUARD · BUILD · PROVE

Universal Testing Machine. The rate is part of the result.

Name: Universal Testing Machine
Brand: Neometrix
SKU: NMX-UTM-101

A universal testing machine pulls, squeezes or bends a specimen until it fails, and records the force and the stretch together. A hydraulic frame carries the load, a cylinder makes it, a load cell and an extensometer measure it, and a controller sets the rate. Neometrix engineers it as a system: the frame, the hydraulics, the alignment, the guard and the proof.

So the machine has to hold the rate it is told, load the specimen along its own axis, and keep people clear of a specimen that fails.

Discuss a universal testing machine Capability note (PDF)

A hydraulic universal testing machine on a plain white studio background: a tall pale grey load frame with a heavy base, four polished steel columns, a fixed upper crosshead and a moving lower crosshead, a load cell under the upper crosshead, two wedge grips holding a slender steel specimen with a clip-on extensometer on its middle, a hydraulic cylinder in the base, a pale grey power unit with a black motor joined by two black hoses, a plain pale grey control cabinet on small wheels with a blank front, and no people

Fig · 01 — A hydraulic universal testing machine: a stiff frame with a moving crosshead, a specimen in grips with an extensometer, a power unit and a control cabinet — illustrative render.

The result

a curve you can trustforce against stretch, to failure

The rate

held at the set valuethrough the yield, when the load stops rising

The line

along the specimen's axisso that it is not bent as it is pulled

The force

verified, not assumedagainst a reference force transducer

Status

engineered to orderno delivery is claimed

ISO 9001ISO 14001ISO 6892-1 reference for tensile testing of metalsISO 7500-1 reference for verifying testing machines

Overview

What a universal testing machine has to get right, and what goes wrong when it does not.

Because the number that comes out is the strength of a material, and a wrong number is trusted.

The gripping zone of a universal testing machine on a plain white studio background: an upper and a lower steel wedge grip holding a slender flat steel specimen with a narrow gauge section, a small steel clip-on extensometer with two thin arms on the gauge section, a load cell above the upper grip, the top of a chrome ram below the lower grip, and no people

Fig · 02 — The grips: a specimen with a narrow gauge section held by two wedge grips, with an extensometer clipped on its middle — illustrative render.

The rate is part of the result.

What the machine is for

It loads a specimen slowly until it fails, and records the force and the stretch together. From the curve come the yield, the strength, the elongation and the stiffness of the material. It serves test laboratories, quality departments and research centres.

How it tests

A specimen is held between two grips. A hydraulic cylinder moves one grip, a load cell measures the force, and an extensometer clipped on the specimen measures the stretch.

Why the rate is part of the result

Most materials are stronger when they are stretched faster, and soft materials such as rubber and plastics change a great deal. So the standards set the rate, and a result taken at another rate is a different result.

Why the machine has to hold the rate through the yield

At the yield the load stops rising and the specimen stretches fast. A machine that only pushes at a set speed lets the strain rate change just there. So the controller reads the extensometer and holds the strain rate, and the loop is closed.

Why the pull is along the axis

A specimen that is pulled off its axis is bent as well as stretched, and the result reads wrong. So the frame is aligned, the grips are set square, and the alignment is checked on a test specimen.

Why the grips matter

A specimen that breaks in the grip is not a valid test. The grips hold the ends without crushing them or letting them slip, and they are chosen for the shape and the material of the specimen.

Why the force is verified

The number the machine reports is only as good as the force measurement behind it. So the force system is verified against a reference force transducer, and the machine is classed by how closely the two agree.

Why a shield stands in front of the grips

A specimen that breaks releases the energy stored in the specimen and the frame at once, and a brittle specimen can fly apart. So a shield stands in front of the grips, and a relief valve and an emergency stop limit the hydraulics.

Why a hydraulic frame

Hydraulics give a large force from a compact cylinder, and they suit metals and structural parts. Soft materials and light loads are often tested on screw-driven frames, and the drive is chosen with the customer.

The method

Duty, frame and hydraulics, grips and measurement, control, build and prove.

Six steps in a fixed order. The rate and the proof are the two that a quick job skips.

1 · Duty

The materials, the specimens, the standards the tests follow, the range of force, the range of rate, and the temperatures are noted.

2 · Frame and hydraulics

A stiff frame, a cylinder and a power unit are matched to the force, with a relief valve that limits it. The frame is stiff, so that it stores little energy.

3 · Grips and measurement

Grips for each specimen, a load cell and an extensometer are chosen, and the force system is verified against a reference.

4 · Control and guard

The controller holds the rate, from the force or from the stretch, and a shield and an emergency stop protect the operator.

5 · Build

The frame, the cylinder, the power unit and the shield are built and fitted, and the load train is aligned.

6 · Prove

The machine tests proving specimens, the rate and the alignment are checked, the force is verified, and the record goes with it.

Which fault, which safeguard

What can go wrong	Why it happens	What the machine does about it
The result is not repeatable	the rate was not held	closed-loop control of the rate, from the extensometer or from the force
The yield reads high or low	the strain rate ran away at the yield	a controller that reads the specimen, and not only the crosshead
The specimen breaks in the grip	the grip crushes it or lets it slip	grips chosen for the specimen, and set square
The stress reads wrong	the specimen is bent as well as pulled	an aligned load train, checked on a test specimen
The force reads wrong	the force system has drifted	a load cell verified against a reference force transducer
A specimen flies apart	stored energy is released at once	a shield in front of the grips, a stiff frame and an emergency stop
The cylinder is overloaded	the pump is stronger than the frame	a relief valve set for the rating of the frame

The step people underrate is the rate. A machine can be strong, and still give a different answer on every day that it is run.

Work content

What the machine contains, element by element.

Read it as a checklist: a machine missing a row will break a specimen, but it will not tell you the truth about it.

A set of universal testing machine accessories laid out on a plain white studio background: a round and a flat steel tensile specimen, a specimen broken in two pieces with a rough fracture, a pair of toothed wedge grip inserts, a steel clip-on extensometer with two thin arms, and a split collet grip in two halves, and no people

Fig · 03 — The accessories: specimens of two shapes and one broken in two, wedge grip inserts, an extensometer and a split collet grip — illustrative render.

Element	What it does	What matters
Load frame	carries the load	a stiff frame with a fixed upper crosshead and a moving lower one, that stores little energy and holds the load train in line
Cylinder and power unit	make the force	a cylinder and a pump matched to the force, with a relief valve that limits it, and a return that is controlled
Control valve	sets the rate	a valve that lets the controller move the cylinder slowly and steadily, and hold it
Load cell	measures the force	a load cell in the load train, verified against a reference force transducer
Extensometer	measures the stretch	an extensometer clipped on the gauge section of the specimen, so that the stretch is the specimen's own
Grips	hold the specimen	wedge grips and inserts for each specimen, that hold the ends without crushing them or letting them slip
Alignment fixtures	keep the pull in line	a way to set the grips square and to check, on a test specimen, that the specimen is not bent
Controller and software	hold the rate and record the curve	closed-loop control from the force or from the stretch, and a record of force against stretch to failure
Temperature chamber	tests hot or cold	a chamber around the specimen, for tests at a temperature other than the room's (optional)
Shield	keeps people clear	a shield in front of the grips, and an emergency stop within reach
Testing & documentation	prove the machine first	proving specimens, a check of the rate and the alignment, a verification of the force, a test of the shield and the relief valve, and a record the customer can inspect

The elements that decide the result are the controller and the alignment. The first holds the rate, and the second keeps the specimen from being bent.

Full specification — expand

System	A stiff load frame with a fixed upper crosshead and a moving lower crosshead; a hydraulic cylinder and power unit with a relief valve, or a servo-hydraulic drive with a control valve; grips for each specimen; a load cell and an extensometer; a controller and software that hold the rate and record the curve; alignment fixtures; an optional temperature chamber; a shield and an emergency stop; and proving specimens, force verification and documentation before handover
The One Idea	The rate is part of the result.
Why The Rate Matters	Most materials give a different result at a different rate, and soft materials change a great deal, so the standards set the rate; at the yield the load stops rising and the specimen stretches fast, so the controller reads the extensometer and holds the strain rate
Why Alignment Matters	A specimen that is pulled off its axis is bent as well as stretched and the result reads wrong, so the frame is aligned, the grips are set square, and the alignment is checked on a test specimen
Standards	ISO 6892-1 covers tensile testing of metallic materials at room temperature, and ISO 7500-1 covers the calibration and verification of tension and compression testing machines. This page prints none of their requirements, and no edition year. Approval of a machine rests with the customer and the authority they name; none is claimed here
Configurations	A hydraulic load frame, a servo-hydraulic frame, and a frame with a temperature chamber
Scope Boundary	This page is the universal testing machine, which loads a specimen slowly to failure. It is not a fatigue machine, which cycles a load many times (see servo-hydraulic fatigue testing machine), not a compression testing machine for concrete and masonry (see compression testing machine), not an impact machine, which breaks a notched bar in one blow (see materials impact testing machine) and not a force calibrator, which checks a load cell (see force calibration machine). It does not decide the test standard or the specimen, and it does not replace the operator's own judgement. No certification or accreditation is claimed here
Status	Neometrix has quoted against successive universal testing machine and tensile testing machine requirements, and no delivered universal testing machine is claimed.

Configurations

One method, three ways to build the machine.

The method, the alignment, the guarding and the proof are shared. What changes is how the rate is held, and the temperature at which the specimen is tested.

Hydraulic load frame

A stiff frame, a cylinder and a motor-driven pump

For a laboratory that tests metals and structural parts: a frame, a cylinder and a power unit matched to the force, with the rate set from the force and the curve recorded.

Servo-hydraulic frame

A control valve and a closed loop, so that the rate is held from the stretch

For work where a standard fixes the rate: the controller reads the extensometer and holds the strain rate, through the yield, whatever the specimen does.

Frame with a temperature chamber

A chamber around the specimen, for tests hot or cold

For tests at a temperature other than the room's: a chamber on the frame, with the grips and the extensometer chosen to work inside it.

And the part that is not equipment at all, yet decides all three: the test plan and the standard. They are written from the customer's own materials and tests, not from the machine.

The drawings

A reference set, drawn as real CAD sheets.

Two sheets of one reference configuration: the arrangement of a hydraulic universal testing machine with three details, and its hydraulic and control circuit. They show the load frame, the curve and the rate, the alignment, the shield, the servo valve and cylinder, the two feedbacks and the control loop. They carry tags and letters only. Every force, rate, speed, stroke and quantity is fixed by design for the customer's tests.

Reference drawing sheet one, the arrangement and details of a hydraulic universal testing machine. A front elevation shows the base, the cylinder and ram, the moving crosshead, two columns, the fixed crosshead, the load cell, two grips holding a specimen with a clip-on extensometer, the power unit and the controller. Detail A shows an engineering curve of stress against strain with the yield, the maximum and the fracture marked, and the rate held along it. Detail B shows a load train on one axis against one with an offset that bends the specimen, and Detail C a plan with a shield on three sides and the operator behind it. An item list numbers eleven parts. A title block stamped reference configuration, not for construction

Fig · 04 — Sheet 01, the arrangement: the load frame in elevation, the curve and the rate, the alignment of the load train, and the shield. Reference configuration, letters only.

Reference drawing sheet two, the hydraulic and control circuit of a universal testing machine. A power unit with a reservoir, a motor and pump, a filter, an accumulator, a relief valve and a gauge feeds a servo valve that drives a double-acting cylinder. The rod carries a load cell and the specimen, and an extensometer is clipped on the specimen. A controller takes the force and the stretch as signals and drives the valve. A block diagram shows the control loop with the set rate, the comparison, the controller, the valve and cylinder, the specimen and the extensometer feeding back, with the load cell as the alternative. A table of what each step does, and a title block stamped reference configuration, not for construction

Fig · 05 — Sheet 02, the hydraulic and control circuit: the servo valve and cylinder, the load cell and the extensometer feeding the controller, and the loop that holds the rate. Reference configuration, tags only.

Every real machine is drawn for its own materials, its own specimens and its own tests. These sheets are the arrangement and the order of working that a project set starts from. Approval of any drawing rests with the customer and the authority they name; none is claimed here.

PDF · two sheets

Reference drawings — arrangement and hydraulic and control circuit

PDF · capability sheet

universal testing machine — what Neometrix engineers

Where it is used

Wherever a material is tested to failure, and the number has to be trusted.

The common thread is a specimen, a standard that sets how it is loaded, and a decision that rests on the number that comes out.

Test laboratories

Where many materials and many specimens are tested to a standard, and the result must repeat from one day to the next.

Quality departments

Where incoming material and finished batches are checked against a specification, and a wrong number costs a lot.

Research and development centres

Where new materials are characterised, and the whole curve matters and not only the strength.

Training institutes

Where students learn what a stress and strain curve is, and the machine is guarded so that they can learn safely.

Watch

See it in motion.

A short walkthrough video of the Universal Testing Machine.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 What does a universal testing machine actually do?

It loads a specimen slowly until it fails, and records the force and the stretch together. The specimen is held between two grips, a hydraulic cylinder moves one grip, a load cell measures the force, and an extensometer on the specimen measures the stretch. The controller holds the rate, and from the curve come the yield, the strength, the elongation and the stiffness of the material. The machine does not decide which test is run or which specimen is cut. That comes from the standard and the customer's own procedure, and the machine is built, set and proved to carry it out.

Q · 02 Why is the rate part of the result?

Because most materials give a different answer at a different rate. Most metals are stronger when they are stretched faster, and rubber and plastics change a great deal. So the standards set the rate, and two machines that test at different rates will give different results for the same material. The hard part is the yield. There the load stops rising and the specimen stretches fast, so a machine that only pushes at a set speed lets the strain rate change just where it matters. The controller reads the extensometer and holds the strain rate, so that the result belongs to the material and not to the machine.

Q · 03 Why does the specimen have to be pulled along its axis?

Because a specimen that is pulled off its axis is bent as well as stretched, and the bending adds to the strain on one side and takes from it on the other. The stress then reads wrong, and a brittle material can break early. So the frame is aligned, the grips are set square, and the alignment is checked on a test specimen fitted with strain gauges, so that the bending is known and kept small. A specimen that breaks in the grip is not a valid test, so the grips are chosen to hold the ends without crushing them or letting them slip.

Q · 04 Why does the machine need a shield, and what happens when a specimen breaks?

Because a specimen that breaks releases the energy stored in it and in the frame at once. A stiff frame stores little, but a brittle specimen can still fly apart, so a shield stands in front of the grips and an emergency stop is within reach. A relief valve limits the force that the pump can put on, and the rating of the machine is the rating of the whole load train, and not of the cylinder alone.

Q · 05 Is this the same as a fatigue machine, a compression machine, an impact machine or a force calibrator?

No, and the differences are worth stating precisely. The servo-hydraulic fatigue testing machine page covers cycling a load many times. The compression testing machine page covers crushing concrete and masonry. The materials impact testing machine page covers breaking a notched bar in one blow. The force calibration machine page covers checking a load cell. This page is the universal testing machine, which loads a specimen slowly to failure in tension, compression or bending. It does not replace any of them, and it does not claim what they claim a second time.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix has quoted against successive universal testing machine and tensile testing machine requirements, and no delivered universal testing machine is claimed. What stands behind the offer is adjacent: Neometrix engineers a servo-hydraulic fatigue testing machine (see the servo-hydraulic fatigue testing machine page), a compression testing machine (see the compression testing machine page) and a force calibration machine (see the force calibration machine page). The grips, the load cell, the extensometer, the control valve, the controller and the software are catalogue items, bought in, not invented. What Neometrix engineers is the machine around them: the frame, the hydraulics, the alignment, the guard and the proof. So the honest position is that the machine is engineered to order, the neighbouring disciplines are in the building, and the first machine of this exact kind will be built around the customer's own materials and tests rather than taken off a shelf.

Q · 07 Which standard applies, and what can the machine not do?

ISO 6892-1 covers tensile testing of metallic materials at room temperature, and ISO 7500-1 covers the calibration and verification of tension and compression testing machines. This page prints none of their requirements, and no edition year: those come from the standard the customer names. The machine loads a specimen slowly to failure. It does not decide the test standard or the specimen, it does not cycle a load, and it does not replace the operator's own judgement. This page claims no certification or accreditation. No force, rate, speed, stroke, stress, strain, capacity or temperature figure is printed here, and approval of a machine rests with the customer and the authority they name; none is claimed here.

Q · 08 What do you need from us to quote?

Six things, and most of them describe your tests rather than the machine. First, the materials: what is tested, whether metal, composite, rubber or plastic. Second, the specimens: their shape and size, and the standard they follow. Third, the force: the largest force, and the smallest that must still be measured well. Fourth, the rate: the range, and whether it is set from the force or from the stretch. Fifth, the temperature: whether tests are run hot or cold. Sixth, the place: the floor, the power supply and the access. From that we come back with a machine concept, a test plan you can check, and a budgetary price.

The neighbouring pages, and how they differ from this one.

Three neighbours: one cycles the load, one crushes concrete, one checks a load cell.

↗ The fatigue machine

Servo-Hydraulic Fatigue Testing Machine

Cycles a load many times - where this page loads a specimen slowly to failure.

↗ The compression machine

Compression Testing Machine

Crushes concrete and masonry - a different job from a tension test on a metal specimen.

↗ The force calibrator

Force Calibration Machine

Checks a load cell - where this page uses one, and has its force system verified.

Browse all Neometrix product lines.

Get a quotation

Tell us the material,
and the test it has to pass.

The projects desk replies within two working days with a machine concept, a test plan you can check, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — universal testing machine Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — UNIVERSAL TESTING MACHINE DUTY · FRAME AND HYDRAULICS · GRIPS AND MEASUREMENT · CONTROL AND GUARD · BUILD · PROVE — THE RATE IS PART OF THE RESULT. ENGINEERED IN NOIDA · INDIA