If you need a jack hammer that shows up every day and just works, the YT29 is that kind of tool. It’s a Pneumatic jack hammer designed for production drilling with an air‑leg, yet it’s steady enough to run as a hand held jack hammer when space is tight. The core numbers are straightforward and field‑friendly: 26.5 kg weight, compact 659 x 248 x 205 mm body, an 82 mm cylinder driving a 60 mm piston stroke, and a working air pressure window of 0.4–0.63 MPa. Water sits at a sensible 0.3 MPa, and air consumption stays at or below 60 L/s, which means your compressor plan won’t get silly. It’s tuned for 34–45 mm holes and typical hole depths around 5 m, so you can plan rounds with confidence.
Quick spec walk‑through (the details you actually use)
Weight: 26.5 kg
Size: 659 x 248 x 205 mm
Cylinder diameter: 82 mm
Piston stroke: 60 mm
Working air pressure: 0.4–0.63 MPa
Working water pressure: 0.3 MPa
Air consumption: <= 60 L/s (about <= 127 cfm)
Air pipe inner diameter: 25 mm
Water pipe inner diameter: 13 mm
Recommended hole diameter: 34–45 mm
Typical hole depth: around 5 m
Why these numbers matter underground
The 82 mm cylinder and 60 mm stroke give a crisp, confident hit. You feel bite, not chatter, which is exactly what you want in 34–45 mm holes.
At 26.5 kg with a 659 mm length, the tool sits well on the leg and doesn’t fight you when you switch to hand held jack hammer work for collaring or corrections.
<= 60 L/s air use is friendly to real compressor fleets. Through a 25 mm ID air line, the Pneumatic jack hammer breathes properly and keeps its pace.
Water at 0.3 MPa through a 13 mm ID hose gives reliable flushing without backflow. Chips move, bits run cooler, and holes stay cleaner and straighter to 5 m.
What it feels like on the face
Predictable rhythm: the tool settles into a smooth beat instead of a ragged slap. That steadiness keeps the steel rotating and the hole tracking straight.
Easy placement: the 659 x 248 x 205 mm frame tucks neatly around ground support. On the leg, it stays planted; off the leg, it’s a manageable hand held jack hammer for quick bursts.
Honest power band: anywhere from 0.4 to 0.63 MPa, it responds the way you’d expect. Many crews choose around 0.5 MPa for a sweet spot between pace and parts life, then nudge up in tougher rock.
Setup and plumbing that protect performance
Measure pressure at the drill, not just at the compressor. Hoses and tees steal pressure; the YT29 still needs 0.4–0.63 MPa at the tool.
Stick to the 25 mm ID air hose and keep runs short and straight. Blow out the line before hookup; grit scores valves and steals power.
Use the full 13 mm water line at roughly 0.3 MPa. Keep water pressure below air pressure to avoid backflow that strips lubrication.
Start/stop routine that works: crack a little air, add water, bring it to working pressure; on shutdown, close water first, then run light air a few seconds to dry internals.
Who the YT29 suits
Crews drilling 34–45 mm holes to about 5 m who want steady results without overbuilding the air system.
Sites where a Pneumatic jack hammer must switch between air‑leg production and hand held jack hammer tasks in tight corners.
Teams that value clean plumbing and predictable air demand (<= 60 L/s) over chasing headline numbers that don’t hold up in the face.
Buyer questions, answered plainly
Q1: Is the YT29 strictly an air‑leg drill, or can it be a hand held jack hammer too?
Both. It’s built for air‑leg production, but it behaves well as a hand held jack hammer for collaring, squaring holes, or working where the leg won’t fit. The 26.5 kg weight keeps it manageable for short tasks.
Q2: What compressor setup do I really need for this Pneumatic jack hammer?
Plan for <= 60 L/s (about <= 127 cfm) at the drill with 0.4–0.63 MPa showing at the tool. Use a 25 mm ID air hose and full‑bore couplings so you actually deliver that pressure and flow.
Q3: What hole sizes and depths are realistic with the YT29?
It’s tuned for 34–45 mm holes to a typical depth around 5 m, assuming you keep flush steady and the bit sharp.
Q4: How should I run water on this jack hammer?
Use the 13 mm ID water line at about 0.3 MPa. Keep water pressure below air pressure. That gives you strong flushing without flooding or backflow, which protects oiling.
Q5: Can I run at 0.63 MPa all shift for maximum speed?
It’s inside spec. Many crews sit closer to 0.5 MPa for a balance of penetration and wear, then bump up when the ground turns stubborn. Watch your chips and adjust.
Q6: How do I avoid stalls or stuck steels?
Keep the flush strong through the 13 mm line, moderate leg thrust so rotation stays lively, and never hammer on a stopped steel. Back off, clear, and restart. It’s faster than fighting a jam.
Q7: What daily maintenance actually moves the needle?
Clean, dry air with steady lubrication. Blow out the 25 mm hose before hookup, check couplings, keep flush ports clear, and give fasteners a quick check. Small habits prevent big downtime.
Q8: How does air consumption <= 60 L/s help the whole setup?
Lower, predictable demand keeps the Pneumatic jack hammer consistent and leaves headroom for other tools. It also reduces pressure sag at the end of long lines.
Q9: Is a Pneumatic jack hammer still a good choice in wet headings?
Yes. Pneumatics are robust in wet, messy conditions and simple to service. You trade some noise for uptime and straightforward safety.
Q10: Will the 26.5 kg weight wear out operators in hand held mode?
It’s not a lightweight, but the balance and compact 659 mm length help. In practice, you use hand held jack hammer mode for shorter, focused tasks—collaring, cleaning, or tight repositioning—then go back on the leg.
Q11: Any plumbing rules I should never break?
Three: use a 25 mm ID air line, use a 13 mm ID water line, and keep water pressure below air pressure. Those three protect performance and parts life.
Q12: What does the 82 mm cylinder and 60 mm stroke change for me?
You get a strong, fast hit that feels planted instead of jumpy. That combination is why the YT29 keeps its tempo in 34–45 mm holes without beating up the operator.
Field tips that add up over a week
Short, straight air lines beat long, snaked runs. Every elbow is lost pressure.
Check pressure at the tool while it’s running, not just static numbers at the compressor.
Swap dull bits early. Forcing thrust only slows rotation and scars the hole.
After a wet shift, let the Pneumatic jack hammer idle briefly on light air to dry internals.
Bottom line The YT29 Pneumatic air‑leg rock drill is a straightforward jack hammer you can plan a shift around: 26.5 kg, 659 x 248 x 205 mm, 82 mm cylinder, 60 mm stroke, 0.4–0.63 MPa working pressure with 0.3 MPa water, <= 60 L/s air use, 25 mm air line, 13 mm water line, 34–45 mm holes to about 5 m. Set it up clean, keep water below air, and oil it properly. Whether you lean on it as a hand held jack hammer for quick fixes or as a full‑time Pneumatic jack hammer on the air‑leg, the YT29 delivers steady, predictable drilling without drama—and that’s what gets rounds finished on time.