Information on the most widely used ASTM standards within the materials testing industry
Model: NJS-10X, ISO 9649, ISO 7800
NJS-10X series Metal Wire Reverse Torsion Tester is used to execute metal wire torsion test, measure the metal wire endure of plastic distortion ability in single or double direction torsion condition; check the surface or internal defect. This test determining the ability of metallic wire of diameter dimension from 0,3 mm to 10,0 mm inclusive to undergo plastic deformation during reverse torsion. This test is used to detect surface defects, as well as to assess ductility. Conform with standard ISO 7800, ISO 9649, ASTM A938.
General Introduction
NJS-10X series Metal Wire Reverse Torsion Tester is used to execute metal wire torsion test, measure the metal wire endure of plastic distortion ability in single or double direction torsion condition; check the surface or internal defect. This test determining the ability of metallic wire of diameter dimension from 0,3 mm to 10,0 mm inclusive to undergo plastic deformation during reverse torsion. This test is used to detect surface defects, as well as to assess ductility. Conform with standard ISO 7800, ISO 9649, ASTM A938.
Key Features
A test piece of wire is twisted a specified number of turns through 360° around its own axis in one direction, and then a specified number of turns through 360° in the opposite direction.

| Symbol | Designation | Unit |
| d | Diameter of a round wire | mm |
| L | Free length between grips | mm |
| N1 | Number of turns in one direction | - |
| N2 | Number of turns in the opposite direction | - |
Dependence of free length between the grips on nominal diameter of the wire
| Nominal diameterd (mm) | Free length between grips L (mm) (nominal) |
0.3 ≤ d < 1.0 1.0 ≤ d < 5.0 5.0 ≤ d ≤ 10 | 200d 100d (1) 50d (2) |
(1) 50d may be used by special agreement. (2) 30d may be used by special agreement. | |
ISO 7800 Metallic materials -- Wire -- Simple torsion test
ISO 9649 Metallic materials -- Wire -- Reverse torsion test.
ASTM A938 Standard Test Method for Torsion Testing of Wire
GB/T 239.1, GB/T 239.2 Metallic materials -- Wire – torsion test.
This Standard specifies a method for determining the ability of metallic wire of diameter dimension from 0,3 mm to 10,0 mm inclusive to undergo plastic deformation during reverse torsion. This test is used to detect surface defects, as well as to assess ductility.
Steel: steel wire, steel rod, steel rebar;
Copper: copper wire, copper rod, copper alloy
Aluminum: Aluminum wire, aluminum rod, aluminum alloy;
Other metal: Rod, glass steel, alloy steel etc.
Main Technical Specification
| Model | NJS-10X |
| Specimen diameter range | 0.3-3mm ; 3-10mm |
| Rotate speed (for steel/aluminum) | 0.1~2 (Number of turns per S) / 1 ~ 120 Rpm |
| Rotate speed (for copper) (optional with extra cost) | 0.1~5 (Number of turns per S) / 1 ~ 300 Rpm |
| Moving guide rail parallelism | <0.2mm |
| Distance between two jaws | 500mm |
| Chuck hardness | 55~65 HRC |
| Max. count circles | 999999 |
| Turning direction | Both directions |
| Power | 220V, 50HZ, 1 phase |
| Dimensions | 1400×370×1100mm |
| Weight | 250Kg |
Main Accessories
| Mainframe | 1 set |
| Moving guide rail | 1 set |
| Deceleration motor | 1 set |
| Safety cover | 1 set |
| Measuring system | 1 set |
| LCD display system | 1 set |
| Weight | 1 set |
| Chuck (0.3~3mm, 3-10mm) | 2 sets |
| Documents (Manual, packing list, certificate) | |
Standard
ISO 7800 specify a unidirectional simple torsion test to evaluate the plastic deformation ability of metallic wire under torsional loading in one direction. It applies to round and shaped wire with diameter or characteristic dimension from 0.1 mm up to and including 14 mm.
ISO 9649 Metallic materials - Wire - Reverse torsion test
This International Standard specifies a method for determining the ability of metallic wire of diameter dimension from 0,3 mm to 10,0 mm inclusive to undergo plastic deformation during reverse torsion. This test is used to detect surface defects, as well as to assess ductility.
A test piece of wire is twisted a specified number of turns through 360° around its own axis in one direction, and then a specified number of turns through 360° in the opposite direction.
ASTM A938 test methods covers torsion testing of wire. It provides knowledge of the ductility of a wire when under torsion loading. A torsional test machine with proper gripping solutions is necessary for the test practices of ASTM A938. It is a testing standard that describes the torsion (or twist) testing procedures of metallic wire. The results of torsion tests can be used to assess wire ductility under torsional loading.
The torsion testing machine should have chuck jaws that will remain coaxial during the test. One of the chucks should be easily displaceable in the direction of the wire axis. The wire should be twisted only along the test length, and not at the point of clamping. We recommend UnitedTest metal wire reverse torsion testing machine.
ISO 15630-3 specifies uniform, repeatable test methods for prestressing steel products: bars, wires, and strands used in prestressed concrete structures. Mainly include tensile test, bend test, reverse bending test, wrapping test, Axial force fatigue test etc.,
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