Dual Guide Tool Crosscut Tester

1. Prepare the test specimen and select the area for test as outlined in ASTM D3359. Inspect the tip of the cutter knife and, if dull from prior use, remove top plastic cap and with only one segment of the cutter extending from the protective plastic housing, place cap over end of the blade and snap off the end segment.
2. Select the thickness of the cuts to be used and remove the lower shoulder bolt from the metal shims of the Dual Shim Assembly which are of this thickness.
3. Place the non-slip instrument on test surface, with all shims in the lowered position. Make the first cut drawing the blade downward with light pressure against the shim in a manner similar to making a straight line with a straight edge. Without moving position of instrument on the test surface rotate the first shim upward and out of the way of the second shim so that second cut can be made using second shim as a guide.
4. Repeat this process until all shims have been rotated upward. Since there are ten shims there will be eleven uniform cuts. Next, rotate the instrument 90° on the test surface and repeat the above procedure to place the same number of uniform cuts intersecting those first produced. Proceed with test outlined in ASTM D3359.

The procedure for making 3mm spaced cuts is identical to the above except two of the shims are rotated upward following each cut. Six equally spaced cuts are produced when operating in this mode. Cuts spaced at 2mm are produced by using the 1mm shims, rotated two at a time for each cut. You can have all of the following mm spacings and still have three cuts in each direction in the cross cut pattern: 1, 1.5, 2, 3, 4, 4.5, 5 and 6. According to discussions heard in the ASTM, the larger spacings are required in some “bridge” and industrial work.