SH129 Grease Drum Stability Tester for Grease Mechanical Shear Stability Test ASTM D1831 The SH129 Grease Drum Stability Tester meets ASTM D1831 and SH/T 0122, the grease roller‑stability testing specification. For operation, load a defined grease specimen and run a 2‑hour room‑temperature cycle on this drum test unit, then compare the worked penetration values of grease pre‑test and post‑test. Designed to evaluate consistency variation of grease after drum‑type mechanical