Test Period
July 2025 – August 2025
Test Personnel
Technician: Mr. Li
Test Objectives
Market Expansion.
Continuous improvement of product quality.
Test Unit & Location
- Test Unit: [Certain] Iron Mine (Hebei).
Test Locations (Levels):
-540m Level (S4-JD-8)
-540m Level (S3-JD-10)
-540m Level (S6-JD-9)
Test Conditions
1. Rock Conditions
Protodyakonov Hardness Coefficient: f13 ~ f15
Corresponding Compressive Strength (UCS): 130 – 150 MPa
(Note: Based on the standard conversion $\sigma_c \approx 100 \times f \text{ kg/cm}^2 \approx 10 \times f \text{ MPa}$, rock with $f=13\text{-}15$ is classified as hard to very hard rock.)
2. Drilling Equipment & Parameters
Jumbo (Drilling Rig): Epiroc (Atlas Copco) Boomer 281
Rock Drill (Drifter) Model: COP 1838HD+
Drilling Parameters:
Feed Pressure (Propulsion): 75–80 bar
Percussion Pressure (Impact): 180 bar
Rotation Pressure: 190 bar
Flushing Water Pressure: 10–12 bar
Test Products & Data
1. Product A: MF Drill Rod (Speedrod)
Specification: ZK23CrNi3Mo H35×4305-T38/R32 (Hex 35mm, Length 4305mm)
Quantity: 8 Pieces
| Serial No. | Service Life / Footage (m) | Failure Mode |
|---|---|---|
| 1# | 3529 | Breakage at Small End Thread (Bit End) |
| 2# | 3753 | Breakage at Small End Thread (Bit End) |
| 3# | 3478 | Breakage at Small End Thread (Bit End) |
| 4# | 3389 | Breakage at Small End Thread (Bit End) |
| 5# | 3645 | Breakage at Small End Thread (Bit End) |
| 6# | 3725 | Breakage at Small End Thread (Bit End) |
| 7# | 3712 | Breakage at Small End Thread (Bit End) |
| 8# | 3549 | Breakage at Small End Thread (Bit End) |
| Average | 3597.5 m | Breakage at Small End Thread (Bit End) – 100% of samples |
2. Product B: Threaded Button Bit
Specification: 9-Button, R32 Thread.
Quantity: 5 Pieces
| Serial No. | Service Life / Footage (m) | Failure Mode |
|---|---|---|
| 1# | 348 | Normal Wear |
| 2# | 352 | Normal Wear |
| 3# | 363 | Normal Wear |
| 4# | 345 | Normal Wear |
| 5# | 356 | Normal Wear |
| Average Service Life: 352.8 m [Data Source: 33] | ||
