GYZJ 934-1 for soft metals such as aluminum and its alloys, brass, copper, and some of the harder plastics and fiberglass. Approximate range 25 to 150 Brinell (10 mm ball 500 kg load). This unit meets American Society for Testing and Materials (ASTM) Standard D­2583.

GYZJ 934-1-0-1 a variation of the 934-1 that has a "flat bottom" shaped support leg. This is used to sit on top of the crest of the round rung of a ladder such as a fire department ladder. Approved by the NFPA, National Fire Protection Agency.

GYZJ 935 for the softer plastics and very soft metals.

GYZJ 936 for extremely soft materials such as lead, linoleum and leather.

Continental Industries will be glad to recommend the most suitable model for your application, if you wish to send a sample of your material to our Barber-Colman facility in the USA. "Barcol" is an abbreviation for "Barber-Colman" and the use of the Barcol readings has been an industry standard for over 50 years.

The Impressor is best suited for testing homogeneous materials. Materials of granular, fibrous or coarse structure will produce a wide variation in hardness readings because of the small diameter of the indenter point.

For accurate readings, material should be at least 1/32" thick for alloys or 1/16" for softer materials and large enough for a minimum distance of 1/8" in any direction from the indenter point to the edge of the specimen. The testing area should be smooth and free from mechanical damage.

Simply exert alight pressure against the instrument to drive the spring-loaded indenter point into the material. The indenter point must be perpendicular to the surface being tested.

On very soft metals, the highest reading should be used since cold flow permits the spring loaded indenter point to continue penetration.

Note: Physical characteristics of very soft materials are such that uniform correlation between different hardness measuring systems cannot be established. For this reason, no conversion curves are offered for the 935 and 936 models. We recommend that Impressor hardness limits for each material be established by test.