Soil Pocket Penetrometer

Model: HM-500
Price: $55.00
Product Files

Gilson Soil Pocket Penetrometer also called a hand penetrometer is constructed of stainless steel. It is a simple, lightweight, handheld device made for instant estimates of the unconfined compressive strength of cohesive soils. Although it does not replace laboratory Unconfined Compressive Strength Test Systems for the determination of unconfined shear strengths, the Pocket Penetrometer is a valuable tool for providing approximate values quickly.

It is specified by OSHA for soil strength estimates when evaluating the stability and safety of trench excavations. Such evaluations can determine the need to modify slope angles or to reinforce excavations with shoring. The penetrometer can be purchased in the Soil Classification Set which includes various tools and instruments for field evaluation and classification of soil characteristics.

The 0.25in (6.4mm) diameter penetration piston is pushed into the soil surface to a groove machined on the piston at 0.25in (6.4mm) depth. Penetration resistance from the calibrated spring is registered on an integrated scale engraved on the penetrometer barrel. Scale units are shown in tons per square foot (tsf) or kg/cm², and a sliding indicator ring retains the reading until reset.

Stainless steel heavy-duty construction of the pocket penetrometer ensures a long, corrosion-free service life. The calibrated steel spring is plated for rust resistance. An optional adapter foot attachment increases the piston diameter from 0.25in (6.4mm) to 1in (25mm), increasing the surface area 16 times for testing very soft soils.

See our full line of Soil Penetrometers.


  • Rapid estimates of unconfined compressive strength of cohesive soils
  • The engraved scale reads directly in tsf or kg/cm² units
  • Indicator ring retains maximum reading
  • Stainless steel construction
  • Meets OSHA regulations for soil trench stability evaluations

Included Items:

  • Soil Pocket Penetrometer
  • Carrying Pouch


  • HMA-15 Adapter Foot Attachment increases the probe diameter to 1in (25mm) for 16 times the piston area for readings in very soft soils.

Related blogs:

Range 0–4.5tsf
Product Dimensions 0.75 x 6.6in (19 x 168mm), Dia.x L
Net Weight 6.8oz (193g)
Estimated Shipping Weight 1.0lb (0.45kg)

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Range 0–4.5tsf
Product Dimensions 0.75 x 6.6in (19 x 168mm), Dia.x L
Net Weight 6.8oz (193g)
Estimated Shipping Weight 1.0lb (0.45kg)
Meets Standard(s):
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