Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes a reciprocable pumping rack movable in response to manual movement of a pumping lever, for pumping hydraulic fluid into a passageway of the tester to increase hydraulic fluid pressure in the tester to a level required for metal hardness testing; and a stent located in the passageway for permitting pumped hydraulic fluid to flow through the passageway into a test head portion of the tester to apply hydraulic fluid to the ball contacting the test piece and interferingly stopping the rack upon movement of the rack into the passageway by a preselected amount.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes a reciprocable pumping rack movable in response to manual movement of a pumping lever, for pumping hydraulic fluid into a passageway of the tester to increase hydraulic fluid pressure in the tester to a level required for metal hardness testing; and a stent located in the passageway for permitting pumped hydraulic fluid to flow through the passageway into a test head portion of the tester to apply hydraulic fluid to the ball contacting the test piece and interferingly stopping the rack upon movement of the rack into the passageway by a preselected amount.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes an adjustable valve for relieving hydraulic pressure within the test head where the valve includes a stem, an interior member, and an intermediate member.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes an adjustable valve for relieving hydraulic pressure within the test head where the valve includes a stem, an interior member, and an intermediate member.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes an adjustable valve for relieving hydraulic pressure within the test head where the valve includes a stem, an interior member, and an intermediate member.

Abstract: A portable Brinell metal hardness tester has a test head mounted in a carriage, movable vertically along elevating screws, and includes an adjustable valve for relieving hydraulic pressure within the test head where the valve includes a stem, an interior member, and an intermediate member.

Abstract: Methods and apparatus for performing Brinell hardness test measurements produce hardness numbers and average Brinell indentation diameter readings automatically and minimize operator intervention and hence, operator error. The apparatus uses a light source, a video camera, a video image digitizer and a computer having a display device. In the method of the invention, electromagnetic radiation is applied to the indentation at an acute angle to the surface of the test specimen in which the indentation has been made. The electromagnetic radiation reflected from the indentation and the surrounding area is sensed. Differences in intensity, such as between light and dark, are digitized and the resulting digital field is numerically analyzed to produce a diameter, preferably major and minor diameters, of the Brinell hardness impression. The diameter or major and minor diameters are used to compute a Brinell hardness number which is displayed by the computer.