Standard Proctor Mold Compaction 6in for Soil Compaction Testing

The Standard Proctor Compaction Mold – 6in is a precision-engineered tool used for soil compaction testing in laboratories and field testing facilities. Designed to meet industry standards, this mold plays a critical role in determining maximum dry density and optimum moisture content of soil samples using the Standard Proctor Test.

Constructed from heavy-duty steel with a plated exterior, the mold offers excellent rust and corrosion resistance, ensuring long service life even under repeated compaction cycles. Studs and wing nuts secure the detachable collar and base plate firmly, allowing easy assembly and quick specimen removal without disturbing the compacted sample.

Purpose of the Proctor Compaction Test

The Proctor Compaction Test evaluates how soil responds when compacted at varying moisture levels. Soil is compacted into the mold in layers using a specified hammer weight and controlled drop height. The number of blows and compaction energy directly influence the test outcomes, making accurate testing tools essential.

Results are plotted on a compaction curve showing dry unit weight versus moisture content. This curve helps engineers identify the optimum moisture content required to achieve maximum density — a critical factor for pavement design, foundation performance, and stable earthwork projects.

Design and Construction Features

The Standard Proctor Mold – 6in includes several design features that enhance accuracy and ease of use:

• Detachable Collar and Base Plate: Provides stable positioning and easy trimming of specimens
• Wing Nut Clamping System: Enables fast assembly and removal
• Plated Steel Construction: Improves durability and corrosion resistance
• Studded Mold Body: Ensures secure attachment during testing

This mold is designed to withstand repeated impacts from soil compaction hammers without deformation, ensuring consistent test results.

For slightly different mold sizes and configurations, you can view the Standard Compaction Mold, 4in, which offers similar build quality and features for smaller diameter Proctor testing. Certified MTP

Available Sizes and Specifications

This Proctor mold is commonly available in standard dimensions suitable for laboratory testing:

• 6in Internal Diameter
• Mold Volume: 1/30 ft³ (0.0333 ft³ / 943 cm³)
• Material: Heavy-duty plated steel
• Base Plate: Detachable steel plate for stability

Precise mold volume and internal dimensions are critical for calculating accurate unit weights during compaction testing.

For alternative mold configurations that allow simpler specimen removal, the Soil Density Split Mold Set, 6in provides a split-body design that eases sample extraction after compaction.

Soil Molds and Sample Preparation

Soil molds are essential in geotechnical testing for determining density and moisture relationships. Proper sample preparation — such as conditioning soil in sealed containers before testing — ensures reliable and repeatable results.

Proctor molds are widely used due to their robustness and compatibility with standard testing methods, including manual Proctor hammers and mechanical compactors. For example, the Manual Modified Soil Compaction Hammer, 18in Drop, 10 lb is a key accessory used to apply uniform blows during compaction tests. 

Required Proctor Test Equipment

In addition to the mold, the Proctor Test typically requires:

• A Proctor compaction hammer with specified weight and drop height
• A laboratory scale for accurate mass measurements
• Moisture determination tools

Each layer of soil is compacted using a specified number of hammer blows to apply uniform energy.

To measure permeability in compacted soil specimens, test facilities often use a 6in Compaction Permeameter, which works with both 4in and 6in mold setups for detailed hydraulic testing. 

Applications

The Standard Proctor Compaction Mold – 6in is used in:

• Geotechnical laboratories
• Construction quality control
• Pavement and foundation design
• Educational and research facilities

By ensuring accurate soil density measurements, this mold supports stronger, safer, and more durable construction outcomes.

For labs needing to perform both compaction and density testing efficiently, complete solutions like the Soil Density Mold Set, 6in provide all key components — body, collar, and base plate — in one kit.

The Standard Proctor Compaction Mold – 6in is a reliable, durable, and industry-approved solution for soil compaction testing. With its detachable components, corrosion-resistant construction, and precise volume, it delivers consistent results for professionals and students alike.