Hardness is one of the most significant physical properties of elastomeric compounds. The hardness reflects all, or in part, such other qualities as resilience, durability, uniformity, tensile strength, and abrasion resistance.

The Model 306L and 408A Scale Durometers are designed to measure the penetration hardness of rubber, elastomers, and other rubber-like substances such as neoprene, silicone, and vinyl and butyl. It can also be used for soft plastics, felt, leather and similar materials. It is built to meet or exceed American Society for Testing and Materials, Specification D2240-81.

Wherever there is a need for checking and standardizing plastic parts, the models 307L and 409D can be used. These cover the broad spectrum of industrial, commercial and military areas. The models 307-L and 409D are designed for plastics— polystyrenes, vinyls, Formica, Plexiglas— hard rubbers and phenolic molded materials. These durometers are used for applications which vary from checking the hardness of contact lens blanks to bowling balls.

The heat-treated, high carbon steel mainspring is precision centerless ground. Each spring is calibrated to the specified tolerances. A special cam arrangement permits a scale deflection of 100 points when the indenter is displaced exactly 0.100".

The non-glare, brushed aluminum dial scale is extended over 240 circular degrees to provide a reading accuracy well within 1% of the calibration curve.

An 8-32 threaded mounting knob at the top of the durometer permits permanent test stand emplacement.

Each durometer is provided with a test block of steel which is far more independent of temperature changes than in a plastic block.

Purchase item

Technical Data

• 	306 and 307	408 and 409
  Range	0 to 100 points
  Accuracy	±1 point
  Dimensions	4" H x 2¼" W x 1¾" D
  Weight	6 oz	8 oz
  Shipping Weight	2 pounds

  For rubber, rubber-like materials and soft plastics
  Model
  306-L	Durometer with Ancillary Hand (Includes Model 401 test block and carrying case)
  408A	Durometer with Ancillary Hand (Includes Model 401 test block and carrying case)

  For plastic and all semi-hard and plastic-like materials
  Model
  307-L	Durometer with Ancillary Hand (Includes Model 402 test block and carrying case)
  409D	Durometer with Ancillary Hand (Includes Model 402 test block and carrying case)