Short answer: jackleg, stoper, sinker and drifter describe how a percussive rock drill is supported and fed into the rock—not simply four power levels. A jackleg uses an angled pneumatic leg for face drilling; a stoper is leg-fed for upward or overhead holes; a sinker is normally hand-held for downward drilling; and a drifter is mounted on a mechanical feed beam or rig. The names are useful for defining the machine class, but they do not prove that drill steels, chucks, controls or spare parts are interchangeable.
For mines, tunneling contractors, quarry crews and distributors, the practical job is to translate a regional equipment name into a complete configuration: drilling direction, support and feed, hole requirement, power source, flushing, shank, site clearance and operator controls. This guide provides that translation.
Jackleg vs stoper vs sinker vs drifter at a glance
| Term | Typical support and feed | Typical drilling direction | Primary distinction |
|---|---|---|---|
| Jackleg / air-leg drill | Rock drill on an angled telescopic pneumatic leg | Horizontal and inclined face holes; some upward angle | The articulated leg supports weight and applies thrust toward the face. |
| Stoper | Rock drill aligned with a telescopic leg beneath it | Upward or overhead holes | The tool-and-leg arrangement feeds toward the back or roof. |
| Sinker / plugger | Hand-held, commonly with T-handles; operator provides feed | Downward and down-angle holes | Portability and direct manual feed rather than a dedicated leg or feed beam. |
| Drifter | Carriage-mounted on a feed beam, rig, column or jumbo | Direction set by the feed and carrier | Machine feed and mounting separate it from hand-held and leg-mounted classes. |
These are functional descriptions, not universal standards. Suppliers and regions may use “air-leg,” “pusher-leg,” “jackleg,” “sinker,” “plugger” or “stoper” differently. The drawing, model, operating manual and interfaces should control the purchase—not the nickname alone.
What is a jackleg rock drill?
A jackleg is a rotary-percussive rock drill supported by a pneumatic feed leg. The leg is normally braced on the floor and angled toward the rock face. As the leg extends, it supports much of the drill’s weight and supplies feed force while the drill piston delivers impacts, the rotation mechanism turns the steel between blows and the flushing circuit removes cuttings.
Jacklegs are closely associated with underground development headings, narrow-vein mining and small tunnels because they can drill face holes without a full drill jumbo. “Jackleg” and “air-leg rock drill” often point to the same functional class, but they are not guaranteed model synonyms. One supplier may sell the drill body and leg as a matched assembly; another may list multiple leg lengths or suffixes.
A buyer should confirm the leg connection, retracted and extended dimensions, feed-control arrangement, drilling direction, water-flushing configuration and drill-steel shank. The active PerfoMax example in this class is the YT28 Air-Leg Pneumatic Rock Drill for 34–42 mm holes. That product reference does not make YT28 components interchangeable with every drill marketed as a jackleg.
What is a stoper rock drill?
A stoper is configured for upward drilling. Its telescopic leg is positioned beneath the drill so the assembly feeds the steel toward the roof or back. The name comes from underground stoping work, although stopers may also appear in raise work, overhead blast-hole drilling and some ground-support operations.
The spelling stoper is the established industry term; stopper drill also appears in searches and quotations. Treat the two words as a language clue, then verify the actual machine. A true stoper configuration needs controls and geometry that can be operated in the intended overhead position. A long air leg fitted to a normal face drill is not automatically a stoper.
Overhead drilling adds falling-rock, water, hose-control and operator-position hazards. Equipment classification never replaces the mine’s ground-control plan, exclusion zones, task training or manufacturer instructions. If the job occurs under unsupported ground, the correct decision may be mechanized bolting or another engineered method rather than a hand-operated stoper.
Stoper feed-travel calculation: can the planned steel change fit?
A stoper can be the correct drill class and still be paired with the wrong steel-change length. The feed cannot use its full nominal travel as drilling advance because part of the steel remains inside the chuck or fronthead. Use the approved machine drawing and steel definition to calculate the usable change before specifying the drill-steel set.
- T = documented stoper feed travel.
- C = length of drill steel retained inside the chuck or fronthead in the working configuration.
- R = any additional reserve required by the manufacturer or site procedure.
- U = maximum usable steel change for planning.
Planning formula: U = T − C − R.
Do not substitute the tool’s extended overall length for feed travel, and do not assume that “H22 × 108” defines the steel-change length. H22 × 108 identifies an interface class; effective length, overall length, collar reference, chuck engagement and bit-end configuration remain separate drawing-controlled inputs.
Worked example
The Compressed Air and Gas Institute air-tools handbook illustrates the relationship with a 25 in feed and approximately 7 in of steel held in the stoper chuck:
- T = 25 in = 635 mm.
- C = 7 in = approximately 178 mm.
- For the handbook arithmetic, R = 0.
- U = 25 − 7 = 18 in, or approximately 457 mm.
This is a method example, not a universal stoper dimension or a PerfoMax model rating. The current machine drawing controls T and C; deduct any required reserve before selecting a steel change. If the proposed change exceeds U, the result is RESELECT, even when the shank fits the chuck.
Stoper and steel-set release gate
| Decision | Evidence required | Next action |
|---|---|---|
| RELEASE FOR RFQ | Exact stoper model and intended upward application are approved; T, C and any reserve are documented; the proposed effective steel change is within U; shank, collar, retainer, taper/bit and flushing path match. | Quote the identified stoper configuration and steel set using drawing-controlled length definitions. |
| CONTROLLED SITE TRIAL | Interfaces and travel calculation pass, but the heading clearance, support point, steel sequence or rock condition is new. | Trial the approved setup under the mine’s ground-control, exclusion-zone and operating procedures. |
| HOLD FOR DATA | Only overall tool length or a nominal rod length is known, or the chuck-engagement and length reference are unclear. | Obtain the machine and steel drawings before selecting a change length. |
| RESELECT | The planned steel change exceeds U, the stoper cannot be supported in the available envelope, or the application lies outside the approved configuration. | Choose a different approved steel sequence, feed length, drill class or mechanized method. |
Copy-ready stoper steel-change record
- stoper make, model and exact fronthead/retainer configuration;
- application: production drilling, raise work, roof bolting or other approved upward task;
- hole direction, target diameter and required depth;
- documented feed travel T and source drawing;
- steel length retained in chuck/fronthead C and reference method;
- required reserve R;
- calculated usable change U;
- proposed steel sequence with each length defined as effective, overall or another controlled basis;
- shank, collar, taper/bit and flushing compatibility;
- available retracted/extended working envelope and support point;
- decision: RELEASE / CONTROLLED SITE TRIAL / HOLD FOR DATA / RESELECT.
Feed travel is only one release gate. Upward drilling also requires site approval for ground condition, falling-material exposure, operator position, hose routing, water return, ventilation and emergency isolation.
What is a sinker rock drill?
A sinker is generally a hand-held pneumatic rock drill used for downward or down-angle holes. The operator controls the tool through handles and supplies feed by body position and tool weight. “Plugger” is another regional name encountered for the same broad class. Small sinkers are used in quarry, construction, utility and secondary drilling tasks where portability matters.
A sinker is not merely a jackhammer pointed at the ground. A rock drill intended to create a borehole combines percussion with controlled rotation and cuttings removal. A demolition breaker normally drives a chisel without continuous drilling rotation or a borehole-flushing circuit. Confusing those outputs leads to the wrong tool, steel and safety plan.
The active Y19A hand-held pneumatic rock drill illustrates PerfoMax’s hand-held route, but a buyer should describe the intended direction and support rather than assuming that every hand-held drill is sold under the word “sinker.” The published hand-held vs air-leg rock drill guide explains the practical Y19A and YT28 distinction.
What is a drifter rock drill?
A drifter is a heavier rock drill mounted on a carriage that travels along a feed beam. The carrier may be a pneumatic column, crawler, quarry drill, tunneling jumbo or another rig. Feed force and alignment come from the machine feed rather than from a hand-held leg. Modern drifters may be pneumatic or hydraulic, so “drifter” does not by itself identify the power source.
Because the feed beam can be positioned by the carrier, a drifter may drill horizontal, inclined, vertical or overhead holes. Direction alone therefore cannot distinguish a drifter from a jackleg or stoper. The decisive features are the rigid machine mounting, guided travel and mechanical feed system.
Do not request a drifter by comparing only impact rate or air consumption with a hand-held drill. A drifter purchase also depends on feed-beam interface, shank adapter, rotation system, hydraulic or pneumatic services, flushing, control system, rod handling and carrier capacity. Those interfaces place it in a different procurement class.
Why drilling direction is useful—but not sufficient
Direction is the fastest first filter: face drilling suggests jackleg, overhead work suggests stoper, and downward hand-held work suggests sinker. However, four additional questions can change the answer:
- Who or what supplies feed? Operator weight, a pneumatic leg and a feed beam create different control and reaction-force conditions.
- How long and accurate must the hole be? A rigid guided feed generally offers more repeatability than a hand-held arrangement.
- How much working space is available? A leg needs a bracing point and extension envelope; a rig needs carrier access and setup room.
- What does the site safety system permit? Ground conditions, unsupported areas, vibration, noise, dust, water and hose routing may rule out a nominally suitable tool.
Machine class is therefore a boundary decision, not a substitute for an application review.
Can one drill body become a jackleg, stoper or sinker?
Some established product families have jackleg, stoper and sinker versions built around related internal architecture. That does not mean a buyer can convert any one into another by adding or removing a leg. Variants can differ in backhead, handles, control location, leg connection, exhaust, flushing parts, chuck, retainer, lubrication path and safety features.
Parts that look alike can also carry different revisions or tolerances. Before approving a conversion or spare-part substitution, obtain the complete model and suffix, serial or production range when available, exploded parts list, leg model, shank specification and photos of the interfaces. Follow the OEM’s approved configuration; do not create an improvised support arrangement.
Buyer decision table: which class should enter the RFQ?
| Job statement | Directionally correct class | Critical confirmation |
|---|---|---|
| Face holes in a narrow underground heading, with a stable floor bracing point | Jackleg / air-leg drill | Leg length and connection, working angle, hole requirement, shank and flushing. |
| Upward holes into the back or roof | Stoper or mechanized bolting/drilling system | Ground-control boundary, overhead controls, leg stroke, clearance and approved method. |
| Short downward holes in accessible stable stone | Sinker / hand-held rock drill | Operator handling limit, hole depth, flushing, shank, air supply and dust control. |
| Repeated production holes requiring guided feed and carrier positioning | Drifter on rig or feed beam | Carrier interface, feed, power system, shank adapter, rods, controls and rod handling. |
Configuration release gate: approve the drilling class, not the nickname
Before a quotation or replacement order is released, treat the proposed class as a controlled decision. A familiar trade name is not enough: the drilling direction, source of feed force, available setup envelope, interfaces, flushing method and site-control boundary must point to the same configuration. If one critical input is unknown, hold the request for evidence rather than selecting the nearest-sounding machine.
| Control input | Evidence required | Release condition | Hold or reselect condition |
|---|---|---|---|
| 1. Hole direction and angle range | Planned minimum and maximum angle, not only “face,” “roof” or “downhole” wording | The proposed support/feed arrangement is approved for the complete working-angle range | The job includes an angle the quoted configuration cannot safely support or control |
| 2. Feed-force source | Operator-applied, pneumatic leg, in-line stoper leg or guided mechanical feed | The source of thrust is defined and matches the drill body, controls and task | A leg or feed is being added by assumption, or an improvised support is proposed |
| 3. Setup and travel envelope | Floor/bracing condition, retracted and extended dimensions, clearance and escape path | The assembly can be positioned, advanced and withdrawn without trapping the crew or losing control | No stable bracing point exists, clearance is insufficient, or movement enters a prohibited zone |
| 4. Hole and production requirement | Diameter, finished depth, straightness, repetition and cycle expectations | The selected class can meet the requirement within its controlled configuration and site method | The task needs guided repeatability, reach or output that points to a feed beam or mechanized system |
| 5. Drill-string and service interfaces | Shank, steel and bit system; air connection; loaded air demand; water or dry-flushing arrangement | Every interface is identified against the quoted model and revision | Compatibility relies on a generic family name, external appearance or an unverified cross-reference |
| 6. Controls and operator position | Control location, intended working posture, hose route and line-of-fire review | Controls remain reachable and the operator can stay in the approved working position | Overhead, inclined or confined use makes the controls inaccessible or puts the operator in an unacceptable exposure path |
| 7. Site-method boundary | Ground-control release, dust/water controls, manual, training and competent-person approval | The site method permits the proposed hand-operated or leg-supported class | Unsupported ground, incomplete controls or site rules require mechanization or another engineered method |
Use one of four release decisions
- RELEASE JACKLEG / HAND-HELD CONFIGURATION: all critical inputs are controlled and the active commercial class matches the full job.
- CONDITIONAL RELEASE: the class is suitable, but the quotation must state a controlled condition such as a verified leg, working-angle limit, hose package or drill-string interface.
- HOLD FOR EVIDENCE: a critical drawing, model suffix, dimension, loaded-air measurement, site approval or application input is missing.
- RESELECT / MECHANIZE: the task exceeds the controllable envelope of the proposed hand-held or leg-supported system, or the site method prohibits it.
Copy-ready class approval record
Job / location: ____ Hole direction and angle: ____ Diameter / depth: ____
Proposed class: jackleg / stoper / sinker-hand-held / drifter-mechanized Feed source: ____
Drill model and revision: ____ Leg or feed model: ____ Shank / steel / bit: ____
Loaded air and hose evidence: ____ Flushing method: ____ Setup envelope checked: yes / no
Site-method approval reference: ____ Decision: release / conditional / hold / reselect
Conditions or missing evidence: ____ Approved by / date: ____
This gate does not approve a stoper or drifter that PerfoMax does not actively list. It defines when the current rock-drill range is a natural match and when the inquiry must remain open for a different engineered solution.
Common terminology mistakes that create purchasing loss
- Ordering by nickname: “Send a jackleg” omits the drill model, leg, shank, hose and flushing interfaces.
- Equating hole direction with machine class: a rig-mounted drifter can drill downward, but that does not make it a sinker.
- Treating air-leg as universal compatibility: the leg connection and suffix must match the drill configuration.
- Assuming shared family parts are interchangeable: similar external shape is not a controlled cross-reference.
- Confusing drilling with breaking: a rock drill creates a borehole using percussion, rotation and cuttings removal; a breaker delivers impact to a chisel.
- Ignoring the complete air system: compressor delivery, hose pressure loss, lubrication and water supply affect whether the selected machine can operate as specified.
RFQ checklist for pneumatic rock drill class and configuration
- Use case: development face, stoping, roof/raise, quarry, construction or another defined task.
- Drilling direction and angle range.
- Hole diameter, finished depth, expected straightness and production requirement.
- Rock description, fractures and water conditions.
- Required support: hand-held, air leg, stoper leg, column or feed beam.
- Available setup space, floor bracing point and overhead clearance.
- Rock-drill make, complete model, suffix and nameplate photos.
- Air pressure and flow available at the tool under load, plus hose length and inside diameter.
- Wet or dry flushing arrangement and site dust-control requirement.
- Drill-steel shank dimensions, steel family, length and bit connection.
- Leg model, stroke and drill-to-leg interface if applicable.
- Requested scope: drill only, matched leg, lubricator, hoses, steels, bits or spare-parts kit.
- Applicable site rules, operator training and documentation requirements.
For component-level understanding before completing that list, see Pneumatic Rock Drill Anatomy: How the Piston, Valve, Rifle Bar, Chuck, and Flushing Work.
Frequently asked questions
Is a jackleg the same as an air-leg rock drill?
They usually describe the same functional class: a hand-operated rotary-percussive drill supported and fed by a pneumatic leg. Because names vary by market, confirm the drill model, matched leg, connection and intended working angle.
What is the difference between a stoper and a jackleg?
A jackleg normally uses an angled leg to feed the drill toward a face. A stoper is arranged in line with its leg for upward or overhead drilling. The controls, geometry and approved applications can differ even when the internal drill family is related.
Can a sinker drill horizontally?
A hand-held drill may physically be used at different angles within its approved operating envelope, but “sinker” describes a class optimized for downward manual feed. Sustained horizontal face drilling generally points to an air-leg system that supports weight and applies feed.
Is a drifter always hydraulic?
No. Drifters can be pneumatic or hydraulic. The defining feature is carriage mounting and guided mechanical feed on a beam or rig, not the energy source alone.
Do jackleg, stoper and sinker drills use the same drill steel?
Sometimes related variants accept the same shank family, but the name cannot prove it. Confirm chuck size, shank length and geometry, retainer, steel system and bit connection against the exact model documentation.
Technical references and evidence boundary
- NIOSH/CDC: Jackleg Drill Usage and Accidents — supports the operational and ground-control boundary for jackleg work; it does not certify a model or conversion.
- NIOSH Engineering Controls: Reducing Hazardous Dust Exposure When Rock Drilling — supports the need for maintained wet or dry dust controls; the site procedure and exact equipment manual remain controlling.
Translate the job into a matched PerfoMax configuration
If the requirement is a leg-supported face-drilling system, review the active YT28 air-leg pneumatic rock drill. Send the drilling direction, hole size and depth, rock condition, available air and water, drill-steel shank and required supply scope with the inquiry. PerfoMax can then respond to a defined air-leg or hand-held requirement instead of relying on a regional nickname.