Sandvik / Tamrock
550 091 04a O-Ring
Rock Drill Spare Part
| Part Number | 550 091 04a |
| Description | O-Ring |
| Brand | Sandvik (Tamrock) |
| Assembly | Hydraulic Motor, Gerotor |
| Type | Rock Drill Spare Part |
Quick answer
550 091 04a (also written 55009104a, 550-091-04a, or 550.091.04a) is a Sandvik o-ring spare part used in the Hydraulic Motor, Gerotor assembly of the Sandvik DD321-40. Verified compatible with 25 Sandvik machine models including COMMANDO DC300Ri, DC302R, DD320S. Used in 10 drifter configurations (HFX5, HFX5T, HL500). Available as an aftermarket replacement drill part from BK Drilling — Turkey-based Sandvik and Epiroc spare parts supplier serving mining contractors worldwide. Quote on request via WhatsApp; typical lead time 3-7 days for stock items.
Part code alternate forms: 55009104a, 550 091 04a, 550-091-04a.
Compatible machines
25
Drifter configurations
10
OEM cross-reference
550 091 04a
About Sandvik 550 091 04a O-Ring
A precision-molded sealing element for the Sandvik DD321-40, this O-ring is used in the Hydraulic Motor, Gerotor to create a reliable static or dynamic seal. Even minor O-ring deterioration can lead to system pressure loss, so scheduled replacement during routine maintenance is strongly recommended.
This is an OEM-compatible aftermarket replacement part for the Sandvik DD321-40 (DD321-40). Also compatible with Tamrock branded equipment of the same model series. BK Drilling supplies this part with fast worldwide shipping and competitive pricing.
Frequently asked questions
Why do O-rings fail in drilling equipment?
O-rings fail due to chemical degradation from hydraulic fluid, extreme temperature cycling, excessive pressure spikes, improper installation (twisting or pinching), and age-related hardening. Using the correct material compound for each application is critical.
