Upgraded TensileTurn CNC – Classic Model for Round Specimen Prep

How To Set Up A Universal Testing Machine For Accurate Tensile Results

Treat the UTM as a closed-loop system. Before the run, confirm force calibration is current per ASTM E4 or ISO 7500-1. Warm the electronics, zero load and displacement, set the gauge length to 2 in (50 mm), attach the extensometer, then apply a small seating load around 20 lbf (90 N). Check axial alignment or verify it with an alignment fixture to meet ASTM E1012 bending limits. Select the control mode required by the method. Metals commonly use strain or stress rate per ISO 6892-1, while many plastics follow crosshead separation under ASTM D638. Program the rate used to capture yield, then the rate allowed for elongation. A practical example is 0.05 in/min (1.3 mm/min) through yield, then 0.5 in/min (12.7 mm/min) to fracture when permitted. Verify the actual speed with a rate check or per ASTM E2309 and record it in the test file. Grip choice and hardware sizing affect data quality. Serrated wedge grips limit slip on metals, pneumatic grips reduce damage on thin sheets and films. Match frame capacity to expected loads, such as 11,240 lbf (50 kN) for routine coupons and 134,900 lbf (600 kN) for heavier sections. Select an extensometer with travel near expected elongation, for example 1.0 in (25 mm). If you would like to review available frames and accessories, you can explore details on the All Tensile Testing Equipment equipment page.

When Should a UTM Run in Strain, Displacement, or Load Control?

UTMs can run closed-loop on strain, displacement, or load. Mode selection shapes data quality. For metallic tension per ASTM E8 and ISO 6892-1, use strain control through modulus and yield. Mount a clip-on or non-contact extensometer on a 2 in (50 mm) gauge length. Many labs switch to displacement after uniform elongation to keep the test stable as necking starts. Displacement control suits plastics and composites where standards specify crosshead rate, such as ASTM D638 or ISO 527. Typical rates range from 0.2 to 20 in/min (5 to 500 mm/min) depending on specimen type. Check grip pressure, jaw condition, and alignment to prevent slip, since crosshead feedback references machine motion rather than true strain. Load control fits proof loading, seating, and holds. A common routine is ramp to 5,000 lbf (22.2 kN) and hold 60 s. Select a load cell so the expected peak sits near 60 to 80 percent of capacity. TM-EML frames deliver ±0.5 percent of reading when verified to ASTM E4, and alignment checks to ASTM E1012 limit bending. Calibrate speed and strain channels before each lot. If you would like to compare control features and frame capacities, you can review options on the All Tensile Testing Equipment page.

How Do UTMs Measure Strain Accurately, And When Should I Use An Extensometer Instead Of Crosshead Displacement?

A UTM reads force through a calibrated load cell, then derives deformation either from an extensometer on the gauge section or from crosshead travel. For modulus, yield offset, and uniform elongation in metals per ASTM E8 or ISO 6892, use a classed extensometer and a defined gauge length such as 2 in (50 mm). Crosshead displacement includes frame and grip compliance, so it skews elastic data and early plastic behavior. Operators typically run the clip-on or non-contact extensometer through uniform deformation, then remove it before fracture to protect the sensor. As a rule of thumb, if expected strain is 25%, a 2 in (50 mm) gauge length will extend about 0.5 in (12.5 mm); plan removal just before that travel. After removal, continue under position control to break and record force and crosshead displacement while preserving the elastic data already captured by the extensometer. If the method specifies a strain or extension rate, compute crosshead speed from the target and L0. Example: a 0.05 per minute strain rate on a 2 in (50 mm) gauge translates to 0.10 in/min (2.5 mm/min). Verify the force accuracy class per ASTM E4 or ISO 7500-1 before testing. If you would like to compare electromechanical frames and extensometer options, you can review details on the Tensile Testing Equipment equipment page.

Which UTM Components Most Affect Tensile Test Accuracy?

Start with the force path. Choose a load cell that keeps expected peak load between 10% and 90% of capacity, then verify calibration per ASTM E4 or ISO 7500-1. For example, a 10,000 lbf (44.5 kN) cell provides better resolution for sub-size coupons than a 50,000 lbf (222 kN) cell. Rigid mounting and a clean electrical connection reduce noise during low-force segments of the test. Gripping and alignment drive repeatability. Match jaw faces to the material and thickness, for sheet metals use serrated or wave faces, for softer plastics use rubber-faced inserts. Seat the specimen square in the grips and remove slack before preloading to avoid off-axis bending. Many labs confirm alignment with an ASTM E1012 fixture or use self-aligning grips to keep bending strain within limits. Measure strain with an extensometer that matches the required gauge length, such as 2 in (50 mm) for ASTM E8 metals or 1 in (25 mm) for small plastics. Zero at a modest preload, such as 5 to 10 lbf (22 to 44 N). Set control mode and speed to the standard, typical metals programs run near 0.05 to 0.5 in/min (1.3 to 13 mm/min) unless strain-rate control is specified by ASTM or ISO 6892-1. If you would like to review frames, controllers, and strain measurement options, you can explore details on the Tensile Testing Equipment equipment page.

How Do I Size And Specify A Dual-Column Electromechanical UTM For Metals Testing?

Start with peak force. Select a frame and primary load cell that keep your expected maximum result near 70 to 80 percent of capacity. For high-strength steels, a dual-column unit covering about 11,000 to 225,000 lbf (50 to 1,000 kN) fits most lab programs. Choose grips rated above your peak by at least 20 percent, for example 15,000 lbf (67 kN) wedges for a 10,000 lbf test. Match jaw faces to the specimen surface to limit slip and bending. Specify accuracy to the method. ASTM E4 and ISO 7500-1 Class 0.5 are common targets for metals. Plan verification on the test axis with traceable force standards. Pair the load cell with an extensometer that matches your gauge length and strain range, such as 2 in (50 mm) for ASTM E8 or 50 mm for ISO 6892-1. Align the specimen using crosshead guides, then set travel limits before loading. Check control capability. For method B strain-rate work, you need stable closed-loop control and fine speed resolution down to roughly 0.000002 in/min (0.00005 mm/min). Overload trip near 103 percent protects sensors, and high sampling, for example 1200 Hz, captures yield events without dropouts. If you would like to review capacities, strain-rate control, and grip options, you can explore details on the TM-EML Series D UTM product page.

Upgraded TensileTurn CNC – Classic Model for Round Specimen Prep

What’s New in Classic Upgrade?

What is TensileTurn CNC and Why Does It Matter?

How TensileTurn CNC Simplifies Laboratory Workflows

Technical Features and Specifications

A Complete Solution for Modern Testing Labs

How To Set Up A Universal Testing Machine For Accurate Tensile Results

When Should a UTM Run in Strain, Displacement, or Load Control?

How Do UTMs Measure Strain Accurately, And When Should I Use An Extensometer Instead Of Crosshead Displacement?

Which UTM Components Most Affect Tensile Test Accuracy?

How Do I Size And Specify A Dual-Column Electromechanical UTM For Metals Testing?