JB-NX Digital Torsion Testing Machine for Metallic Materials (Jiubin Instruments)

Overview

The JB-NX Digital Torsion Testing Machine, engineered by Jiubin Instruments, is a precision-engineered, horizontal-axis electromechanical system designed for static and quasi-static torsional characterization of metallic materials and mechanical components. Based on the fundamental principles of torsional mechanics—governed by the relationship between applied torque (T), angular displacement (θ), and material shear modulus (G)—the JB-NX delivers repeatable, traceable measurements of torsional stiffness, yield torque, ultimate torsional strength, and plastic deformation behavior under controlled rotational loading. Its rigid cast-frame architecture, high-fidelity torque transduction via symmetrical strain-gauge sensors, and high-resolution angular measurement using optical rotary encoders ensure metrological integrity aligned with ISO 7500-1 (Class 1) and ASTM E143 for torsion testing systems. The machine operates in closed-loop mode, enabling both torque-controlled and angle-controlled test protocols essential for evaluating fasteners, drive shafts, springs, and structural connectors.

Key Features

• Horizontal卧式 Design with Rigid Cast Frame: Minimizes gravitational bending moments and ensures axial alignment stability during high-torque loading; frame constructed from stress-relieved grey iron casting for long-term dimensional stability.
• Dual-Mode Control Architecture: Supports both torque-setpoint and angle-setpoint operation via the embedded TESTSMART digital control system, facilitating compliance with multi-step torsion protocols (e.g., preload–hold–twist sequences per ISO 898-7).
• High-Fidelity Transduction System: Symmetrical bridge-type torque sensor with ±1% full-scale accuracy and 1/20000 resolution; absolute-angle measurement via 2,000-line-per-revolution optical encoder (0–1000 rad range, ±1% accuracy).
• Variable-Speed Drive System: Integrated high-precision reduction gearbox coupled with a frequency-inverter-controlled AC motor (Delixi brand), delivering smooth, non-impact loading across a wide speed range with ±1% speed regulation accuracy.
• Human-Centered Operator Interface: Full-color LCD display with native Chinese GUI; intuitive menu navigation structured around standardized test workflow logic—parameter setup → specimen mounting → test execution → data review → report export.
• Comprehensive Safety Integration: Hardware-level overload cutoff, current-limiting circuitry, emergency stop interlock, and software-enforced torque/angle limits prevent mechanical overtravel or sensor saturation.

Sample Compatibility & Compliance

The JB-NX accommodates cylindrical metallic specimens with diameters ranging from 8 mm to 25 mm and adjustable gauge lengths from 0 mm to 300 mm—enabling evaluation of standard test bars (per ISO 7800), threaded fasteners (M6–M24), torsion springs, and small-diameter shafts. Chucks are fabricated from vacuum-hardened 40CrNiMoA alloy steel (HRC 45–50), ensuring wear resistance and consistent clamping force distribution. The system supports testing under ambient laboratory conditions (10–35 °C, ≤80% RH) on vibration-isolated foundations. While not certified to GLP or GMP out-of-the-box, its deterministic control architecture, audit-ready parameter logging, and deterministic calibration traceability make it suitable for internal QC labs operating under ISO/IEC 17025 quality management frameworks. Data outputs comply with ASTM E1392 requirements for digital test record retention.

Software & Data Management

The embedded TESTSMART firmware provides real-time acquisition of torque (N·m), angular displacement (rad), and rotational velocity (rad/s), with synchronized timestamping at ≥100 Hz sampling rate. Test profiles—including ramp rates, hold durations, and limit-triggered actions—are programmable via on-device interface. Raw data exports in CSV format support post-processing in MATLAB, Python (NumPy/Pandas), or Excel. Optional PC-based software (sold separately) adds advanced features: multi-curve overlay, derivative analysis (dT/dθ for stiffness mapping), statistical reporting (mean, SD, CV%), and customizable PDF report generation with lab header, operator ID, calibration certificate references, and test standard citations (e.g., “Test conducted per ISO 7500-1:2018 Annex B”). All system configurations and test logs are stored internally with time/date stamps for traceability.

Applications

• Mechanical property validation of cold-formed and heat-treated steel rods, wires, and pins
• Torsional fatigue pre-screening of automotive suspension components and driveline couplings
• Quality conformance testing of bolts, screws, and threaded inserts per ISO 898-7 and SAE J429
• Characterization of torsional spring rate and hysteresis in precision instrumentation springs
• R&D evaluation of new aluminum alloys and titanium grades under pure shear loading
• Educational demonstration of Saint-Venant’s torsion theory and warping effects in non-circular sections

FAQ

What torque ranges does the JB-NX support?
The JB-NX is available in two standard configurations: 50 N·m and 100 N·m maximum capacity. Both models maintain 1% accuracy across 1–100% of full scale.
Can the system perform angle-controlled tests?
Yes—the TESTSMART controller allows precise angular positioning and dwell control, enabling tests such as torsional relaxation, creep, and stepwise angular loading.
Is calibration documentation provided with shipment?
Each unit ships with a factory calibration certificate referencing traceable standards (NIM or CNAS-accredited secondary standards); annual recalibration is recommended per ISO/IEC 17025 guidelines.
Does the JB-NX meet international standards for torsion testing?
Its mechanical design, measurement uncertainty budget, and control repeatability align with ISO 7500-1 Class 1 requirements; users must validate protocol-specific compliance (e.g., ISO 898-7) through method verification.
What maintenance is required for long-term reliability?
Routine inspection of chuck surfaces, encoder coupling alignment, and gearbox lubrication every 6 months; no consumables beyond standard industrial grease and periodic sensor zero-checks.