Proctor Penetrometer Set, Replacement Resistance Needle Set

Set of nine, screw-on type, replacement needles for use with the H-4137 mortar penetration resistance apparatus. Set includes: (in² (cm²)) 1 (6.45), 3/4 (4.84), 1/2 (3.22), 1/3 (2.15), 1/5 (1.29), 1/10 (.65), 1/20 (0.32), 1/30 (0.22) and 1/40 (0.16).