| Technical Fit | Machine type | Pneumatic handheld rock drill with an integrated air leg, generally used for drilling downward, horizontal, or inclined blast holes. | Confirms suitability for underground development, tunneling, and small-to-medium-diameter blasting work. | Match the drill to the mine layout, drilling direction, face access, and available compressed-air system. |
| Machine weight | Approximately 25–30 kg for the drill assembly, excluding hoses, drill steel, and accessories. | Affects operator fatigue, positioning time, transport, and productivity in confined headings. | Request the net weight and the operating weight with air leg, lubricator, hose, and drill steel installed. |
| Drilling diameter | Typically about 34–42 mm, depending on rock hardness, bit design, and drill-rod selection. | The hole diameter determines explosive loading, fragmentation, stemming requirements, and drilling speed. | Confirm the recommended bit range, rod diameter, shank specification, and intended rock class. |
| Shank and drill-steel compatibility | Common configurations use a 22 mm shank diameter with approximately 108 mm shank length; exact dimensions must be confirmed. | Incorrect shank dimensions can cause poor impact transfer, premature wear, vibration, or unsafe tool ejection. | Check technical drawings and measure the existing rods, bits, chuck, and retaining components. |
| Impact frequency | Commonly around 35–40 Hz at the rated operating condition. | Higher frequency does not automatically mean higher productivity; rock type, feed pressure, bit sharpness, and air quality also control drilling performance. | Ask for test data at the stated air pressure and compare it with the mine’s actual operating conditions. |
| Air consumption and pressure | Often designed around approximately 0.63 MPa operating pressure, with air consumption commonly about 70–85 L/s, depending on configuration. | Insufficient pressure or flow reduces impact energy, increases drilling time, and may cause unstable operation. | Verify free-air delivery from the compressor, pressure losses through hoses, hose internal diameter, and simultaneous equipment demand. |
| Safety | Water flushing and dust control | Prefer wet drilling with a functional water-feed system; use dust suppression, drainage, and suitable respiratory protection where required. | Reduces respirable crystalline silica exposure and improves visibility at the work face. | Inspect water seals, passages, valves, hose connections, and the site’s water pressure and quality. |
| Noise and vibration exposure | Use the supplier’s measured noise and vibration data; provide hearing protection, anti-vibration gloves where appropriate, job rotation, and exposure-time controls. | Pneumatic rock drilling can create substantial hand-arm vibration and high noise levels. | Request test methods, declared values, and operating limits; compare them with local occupational exposure regulations. |
| Air-line and hose safety | Use correctly rated hoses, locking couplings, whip checks or safety cables, shut-off valves, and fittings secured against accidental separation. | A pressurized hose failure can cause hose whip, impact injuries, and uncontrolled equipment movement. | Check hose pressure rating, coupling retention, inspection intervals, and emergency isolation procedures. |
| Operator controls and ergonomics | Controls should be clearly marked, easy to reach, and capable of shutting down air and water quickly; handles and air-leg controls should permit stable two-hand operation. | Good ergonomics reduce loss of control, awkward postures, and unintended start-up. | Conduct a hands-on trial with the intended PPE and verify the emergency shut-off procedure. |
| Inspection before use | Inspect handles, trigger, air leg, chuck, retainer, hoses, fittings, water system, lubrication system, and drill steel before every shift. | Early detection prevents failures caused by loose parts, worn retainers, blocked passages, or damaged hoses. | Use a documented pre-start checklist and remove defective equipment from service. |
| Maintenance | Air-line lubrication | Use the lubricant specified for the pneumatic motor and maintain a correctly adjusted in-line oiler; never operate with a dry air motor. | Correct lubrication reduces piston, cylinder, valve, and rotation-component wear. | Confirm oil type, oiler capacity, adjustment method, and daily lubrication requirements in the service manual. |
| Water and air cleanliness | Use clean compressed air, drain moisture from the system, and prevent abrasive particles from entering air, water, or lubrication passages. | Contamination accelerates valve sticking, seal damage, corrosion, and loss of impact performance. | Check filtration, separators, water quality, hose cleanliness, and routine drain procedures. |
| Wear parts and serviceability | Key wear parts include piston, cylinder, valve components, seals, chuck, retainer, rifle bar, rotation parts, and air-leg seals. | Availability and ease of replacement directly affect downtime and maintenance cost. | Request a parts list, exploded drawing, recommended replacement intervals, and special-tool requirements. |
| Daily and periodic maintenance | Daily: clean, lubricate, inspect, and drain. Periodically: check fasteners, seals, rotation mechanism, impact components, air leg, and water passages. | A scheduled maintenance plan maintains drilling performance and reduces unplanned failures. | Obtain a maintenance schedule based on operating hours, drilling conditions, and contamination level. |
| Storage and transport | Clean and drain the drill, protect air and water ports, prevent corrosion, and secure the machine during transport. | Moisture and impact damage during storage can shorten the service life of internal components. | Verify storage instructions, protective plugs, corrosion-control recommendations, and lifting or carrying requirements. |
| Supplier Selection | Technical documentation | Complete manual, dimensional drawing, rated operating conditions, parts breakdown, lubrication instructions, and safety guidance. | Clear documentation supports safe commissioning, maintenance, and operator training. | Reject incomplete quotations that provide only headline performance figures without test conditions. |
| Quality and conformity evidence | Look for documented quality-control procedures, material traceability, pressure testing, functional testing, and conformity documents applicable to the destination. | Evidence of controlled manufacturing reduces the risk of inconsistent dimensions and premature failure. | Request sample inspection records, test reports, and applicable certificates rather than relying only on marketing statements. |
| Spare-parts availability | Critical service parts should be available with clear part numbers, interchangeability information, and stated lead times. | A low purchase price can be outweighed by long downtime or unavailable wear parts. | Obtain a recommended two- to six-month spare-parts list based on expected drilling hours. |
| Warranty and after-sales support | Prefer written warranty terms covering duration, exclusions, claim evidence, response time, and technical support channels. | Defined support reduces disputes and helps restore production after equipment problems. | Confirm who handles troubleshooting, replacement decisions, training, and field-service escalation. |
| Factory acceptance and field trial | Use a documented acceptance test covering air pressure, air consumption, rotation, impact operation, water flushing, leakage, controls, and noise or vibration observations. | A controlled trial confirms that the drill performs with the mine’s compressor, hoses, rods, bits, and rock conditions. | Agree on measurable acceptance criteria before placing the order. |
| Total cost of ownership | Compare purchase price, air consumption, drill-steel and bit wear, lubricant use, spare parts, labor, downtime, training, and transport. | Operating cost and availability usually have a greater effect on mine productivity than initial price alone. | Calculate cost per drilled meter using the same rock type, hole diameter, shift length, and maintenance assumptions. |
