Model 401 Tension Proof Tester


The Model 401 Tension Proof Tester can test lumber as large as a 2x6 (38x140 mm) with tensile loads up to 100,000 pounds (440 kN).

The Model 401 Tension Proof Tester grips the test specimen, applies a test load with hydraulic cylinders, and measures the load applied. Maximum load attained while the specimen is loaded to failure is displayed. Polycarbonate shields protect personnel from injury. Endwise loading allows testing of material of any length. The standard Model 401 accomodates material from 3/4 in (19 mm), or from 1.25 in (32 mm) to 2.00 in (51 mm) thick. Modified clamps can accommodate other thickness ranges.

Least expensive Metriguard Tension Proof Tester designed for accurate, low-cost evaluation of lumber sizes up to 2x6 in (38x140 mm). Patented wedge-grip design, with two clamp assemblies, securely holds the specimen inside the steel frame. Basic machine set to operate on a fixed gauge length. Length may be increased with optional push-rods, push-rod extensions or with an optional frame which provides eight fixed gauge lengths. Material inserted on-edge from either end of the machine. Initial clamping force provided by a hand-actuated toggle or an optional pneumatic system. Two hydraulic cylinders, powered by a hydraulic pump, apply the tensile load. Applied load and the force at which lumber failure occurs are measured with optional force measurement systems. The hydraulic gauge is the most economical way to measure tensile force, while the electronic load cell force measuring system is the most accurate and versatile method.


Test Gauge Length

24 in (610 mm), or specified

Maximum Tensile Force

100,000 lb (440 kN), via xxxx hydraulic pressure

Tensile Force Measurement

Select from options

Tensile Force Actuation

10,000 psi (69 MPa) xxxxxx hydraulic cylinders

Maximum Tensile Stroke

2 in (51 mm)

Clamp Force Actuation

From tensile force via split inclined plane Initial

Clamp Force

Hand-actuated toggles; one on each clamp

Clamp Grip Length

23 in (584 mm)

Vertical Centering in Clamps

Provided for material widths 1.5, 2.5, 3.5, and 5.5 in xxxx (38, 64, 89, and 140 mm)

Test Material Size Range


Up to 5.9 in (150 mm)


1.25 to 2.00 in (32 to 51 mm)


>70 in (1780 mm) for full grip coverage and standard gauge length. Shorter specimens allowed with shorter gauge length or reduction in maximum force


Electric Power

115 Vac 50/60 Hz, 7.6 amp (approx.)

Hydraulic Pump

1/2 horsepower pump (standard) HYD-PUM-1001

Pump Specifications

Maximum pressure

10,000 psi (69 MPa)

Oil flow at max pressure

17 in3 /min (280 ml/min)

Valve positions

retract, hold, metered advance, and full advance

Electric control

Pendant on/off switch

Electric power

1/2 hp, 50/60 Hz, single phase, 115 Vac standard, 220 Vac 50 Hz motor available

Reservoir capacity

1155 in3 (18.9 l)

Usable capacity

1150 in3 (18.8 l)


45 lbs (20 kg) (without oil)

Duty Cycle

Heating restrictions limit continuous testing to 30 boards followed by a 60% duty cycle

System Dimensions


101 in (2565 mm)


17 in (432 mm)


16 in (406 mm)

Shipping Weight

1300 lbs (590 kg)

Standard Frame

Includes either standard or metric electronic force measurement system, pedestal, and 1/2-horsepower hydraulic pump. (401-BAS-1501)

Optional Frame

Includes the adjustable gauge length machine frame with either the standard or metric electronic force measurement system, pedestal, and 1/2 horsepower hydraulic pump. (401-BAS-1502)

Test Gauge Length

Push rod extensions available for testing material at gauge lengths from 2 ft ( 610 mm) to 8 ft (2440 mm) in 2 ft (610 mm) increments.

Tension Calibration Link

Includes two wood-faced steel paddles for insertion into the clamps; a tension load cell with steel pins for attachment to the paddles; and a readout unit with gauges. The tension calibration link, when inserted into the Model 401 Tension Proof Tester and brought up to load, gives a completely independent measurement of force for checking the force calibration up to 100,000 lbs (440 kN). (SYS-ASM-1001)