Trade.Information

Details on SM1 Torsion Testing Machine (30Nm)

Features

• Torque capacity up to 30Nm (300lbf in)
• Direct readings of torque and strain
• Digital torque meter
• Suitable for specimen testing to destruction
• Forward and reverse loading capability
• Accommodates specimens up to 750mm long
• Specimens gripped by standard hexagonal drive sockets
• Wide range of standard test specimens
• SM2 Torsiometer available for accurate strain measurement
• Two year warranty
• Complies with the latest EEC Safety Directives

Description

The SM1 MkII Torsion Testing Machine has the same basic features as its well known predecessor but has been improved by introducing a digital torque measurement system and extending the length of the unit to allow tests on longer specimens if required. A rigid square aluminium tube is supported at each end by cast aluminium feet and carries a straining head at one end and a torque measuring system at the other. The straining head consists of a 60:1 worm drive reduction gear box mounted on a special extruded aluminium platform which slides long the square tube and can be locked in any position. The output shaft is free to slide on a keyway in the gear box to accommodate any change in length of the specimen during testing and to enable insertion of specimens. Reaction to the torque applied to the specimen is supplied by the torsion shaft which is supported at each end by self aligning bearings. Test specimens are held at each end by hexagonal drive sockets which fit on the gearbox output and torsion shafts. An arm is fitted to each end of the torsion shaft, the one at the far end being located by a turnbuckle and handwheel for adjusting the angular position of the torsion shaft. The arm at the inner end bears on a dial gauge and can be adjusted using the turnbuckle to maintain one end of the specimen in a fixed position during tests. A linear potentiometer is fitted between the two arms and provides an output proportional to the angle of twist of the torsion shaft.

The potentiometer is connected to a digital meter which reads directly in Nm and lbf in. A calibration arm, weight hanger and weights are supplied for checking or recalibrating the meter if required. Strain of the specimen is measured by protractor scales on the gearbox input and output shafts, these scales being locked in position by knurled thumbnuts. A resettable digital revolution counter is also fitted to the gearbox input shaft to provide a record of total input revolutions in any test. Measurements of specimen strain can be obtained when the torsion shaft is adjusted during a test to maintain one end of the specimen in a fixed position. A Torsiometer, SM2, can be supplied as an extra, if required, for greater accuracy in measuring strain, for example, in determining modulus of rigidity.

Instruction manual

A technical manual is supplied giving a summary of relevant theory, detailed operating instructions and typical test results.

Range of Experiments

1. Verification of the elastic torsion equation.

2. Determination of modulus of rigidity and yield shear stress.

3. Determination of upper and lower yield stresses for normalised steel specimens.

4. Investigation of the behaviour of materials under plastic deformation and the phenomenon of work hardening.

5. Determination of modulus of rupture in torsion.

6. Reversed torsion tests to demonstrate the Bauschinger effect and the effects of residual body and textural stresses on torsional strength.

7. If heat treatment facilities are available a wide range of tests can be carried out to demonstrate the effect of heat treatment on residual stresses and torsional strength.

Specification

Nominal Capacity: 30Nm (300 lbf in)

Gearbox Ratio: 60:1

Two protractor scales:

360 in 1 and 0.1 divisions

Digital counter:

5 digit resettable type (1 rev = 6)

Drive shaft ends: 12.7mm (0.5in) square

Drive sockets:

3/16" Whitworth and 12mm AF hexagonal (2 off each supplied))

Torque meter:

TQ E101 digital Torque measuring system with 3 1/2 digit display and Nm and lbf in changeover switch (supplied as standard with each SM1 MkII apparatus).

Calibration arm: 500mm (20in) long.

Calibration weights:

2 off 2kg,

1 off 1 kg

1 off 500g with 500g weight hanger.

Test Specimens

Each SM1 Torsion Testing Machine is supplied with a starter pack comprising:

6 off TR1010 (MT15)

0.1% carbon steel, as drawn

6mm diameter, gauge length 76mm

Extras

SM2 Torsiometer:

Mechanical Torsiometer for use with 6mm diameter specimens in both the elastic and plastic regions.

SM1A Additional specimen kit:

Consisting of 1 off each of the specimens listed below.

TR1010 MT15

0.1% carbon steel, as drawn

TR1011MT15N

0.15% carbon steel, normalised at 900C

TR1020 MT40

0.40% carbon steel, as drawn.

TR1021 MT40N

0.40% carbon steel, normalised at 860C

TR1040 MTX

Brass 70Cu/30Zn, Half hard

TR1050 MTC1

Cast iron grade 180

Noise

The measured sound pressure level of this apparatus is less than 70 dB(A)

Services Required

Single phase earthed a.c. mains electrical supply 220/240V or 110/120V; 50/60Hz for E101 digital meter. Voltage to be specified on all orders.

Space Required

For satifactory use of this apparatus a bench are of 1.6 x 0.6m is recommended. Alternatively the apparatus may span two benches of the same height.

Dimensions and Weights

Nett: 1550 x 360 x 400mm; 33kg

Gross: 0.3m3; 60kg (approx - packed for export)

Tender Specification

A 30Nm (300lbf in) direct reading torsion machine capable of taking specimens up to 750mm long. Forward and reverse torsion testing facility is essential. Digital measurement of torque is given in Nm or lbf in using a changeover switch. The drive shafts (12.7mm (0.5in)) have 3/16" Whitworth or 12mm AF hexagonal drive sockets. Supplied with sample pack of test specimens. An optional Torsiometer must also be available for use in both the elastic and plastic regions.