HOME„Sand equipment > Greemsamd Mold Hardness Tester

An easy-to-use hardness tester for green sand mold surfaces
Greemsamd Mold Hardness

SummarySpecial Features of GREAT SAVER

Manual

Hardness test methodHardness Measurement

  1. The precision of this hardness tester has been calibrated in the upright position. In other positions certain errors could occur in the mechanism of the tester. Ensure to use the tester only in the upright position.
  2. For measurement, hold the hardness tester firmly in the hand and press it at a constant speed vertically with the flat surface of the tester parallel to the sand mold surface. As soon as the flat surface comes in direct contact with the sand mold surface, read the indicated maximum value. Note that measurement in titled or horizontal directions involves inaccuracy.
  3. The hardness tester is equipped with limiters to define the upper and the lower tolerance. If a hardness range of "505" is defined, for example, you can set the limiters to the upper limit (55) and the lower limit (45), so that you can confirm easily that the measured values are within the tolerance.
  4. The hardness tester has also a (red) stay-in-place needle to show the maximum value of each measurement. Follow the procedures below for setting and reading.
    1. Turn the knob in the middle of the scale counterclockwise and position the red stay-in-place needle near the 0-position.
    2. Make measurements in this condition. When the flat surface of the hardness tester is released from the specimen, the indicator returns to 0 with the stay-in-place needle showing the maximum value (the highest hardness indicated).
Mold Condition Hardness Reading
Very soft rammed sand mold to 20
Soft rammed sand mold from 20`to 35
Normal rammed sand mold from 35 to 60
Hard rammed sand mold from 60 to 75
Very hard rammed sand mold 75 and up

 

Instructions for correct use

The green sand mold hardness tester is a precision measurement device. The following safety and operating instructions must be read carefully to avoid failure or malfunctions.

  1. Avoid disassembling of modification. Avoid loosening the screws.
  2. Avoid shocks like falling or excessive force, etc.
  3. Avoid the use or storage in the direct sunshine, at extreme high or low temperatures, exposure to humidity, dust, oil or water.
  4. void pressing the tester against hard substances such as glass or metal for other purposes than testing or inspection.
  5. Avoid cleaning with organic substances (benzene, thinner, etc.) Avoid lubrication.
  6. Avoid giving perpendicular forces or shocks to the hemispheric needle (gauge head).
    Follow the procecures below for setting and reading.

Maintenance

  1. Ensure that the hemispheric needle (gauge head) and the flat surface are free of impurities before you start measurement.
  2. If the cover is dirty and the scale is hard to read, wipe the cover with a dry or neutral-detergent-dipped cloth.
  3. In case that repair or adjustment is necessary due to failures of the stay-in-position needle, spring load, etc., please contact the sales office or relevant agent of our company. Please note, however, that the hardness tester will not be guaranteed, if repair work or adjustment has been made by someone, who is not authorized by our company.

Periodic Inspections

The green sand mold hardness tester needs regular inspections

  1. Height of hemispherical needle (sensing element)...The tester is to indicate 0 if no load is applied. When the flat surface of the tester is pressed against a flat and rigid surface, the reading should be 100 0/-1
  2. The rounded part of the hemispherical needle (sensing element) should have no excessive wear.
  3. Spring Force...By giving defined loads to the hemispherical needle (sensing element), the respective indication of the needle is to be checked. The values 25, 50, 75 are the checking points.
Check Point Loat
25 1.353N (138gf)
50 1.677N (171gf)
75 2.001N (204gf)
Measurement tolerance is 1 scale unit (1.32gf)

Specification

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Type NK-021(stay-in-place-needle)
Spring Load 1.030 N `@42.324 N
(105 gf - 237 gf)
Press Needle 5.08mm (hemispheric)