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A shock absorber — also called a shock sub — is a drill-string component fitted between the rotary head and the drill string. Inside, a floating piston and layered cushions absorb the shock and vibration created at the bit, so far less of it reaches the rotary head, the threads and the rig.

Directly below the rotary head — between the rotary head (or top sub) and the drill rods. With the optional Safe-Lock, the absorber is clamped to the top and bottom subs, so no welding is needed at the rotary head shaft or the top adapter.

Drilling generates heavy impact and vibration from hard rock, uneven formations and sudden load changes. A shock absorber takes much of that load before it travels up to the rig.

Rotary drilling

The bit crushes rock under rotation and pulldown. A shock absorber:

• absorbs the axial shocks and bit bounce caused by uneven rock;
• protects the rotary head, gearbox, threads and mast;
• keeps uniform pressure on the bit for faster penetration and longer bit life.

DTH drilling

The down-the-hole hammer delivers high-energy blows at the bottom of the hole. A shock absorber:

• absorbs the impact energy reflected back up the drill string;
• protects drill rods, threads and the rig structure;
• reduces fatigue failures caused by continuous hammering.

Result: smoother drilling, fewer breakdowns and lower maintenance costs.

Yes — for different reasons. In rotary drilling it absorbs the shocks and bit bounce caused by uneven rock and keeps the weight on the bit steady. In DTH drilling it absorbs the impact energy reflected back from the hammer, preventing fatigue failures in rods and threads and protecting the rig from continuous hammering.

Yes. Every Samavich SC model is compatible with both rotary and DTH drill strings, for vertical or angled drilling. Pin and box threads are made to suit your rig.

Four types of vibration are common in drilling:

• Axial (bit bounce) — along the drill string; uneven rock or sudden load changes make the bit lift and strike the formation repeatedly.
• Torsional (stick–slip) — the bit momentarily sticks while the string above keeps turning, then releases with a sharp torque spike.
• Lateral (whirl) — side-to-side movement of the string from imbalance, misalignment or unstable formations, wearing tools and the borehole.
• Impact — especially in DTH drilling, where hammer blows send reflected shock loads up the string.

A Samavich shock absorber is designed for axial and impact loads: its cushions compress to absorb bit bounce and reflected hammer energy, so far less vibration reaches the rotary head, feed system and mast. The drilling torque is carried through the absorber by its pins.

Lateral vibration is best controlled with centralisers (deck bushings), which keep the string aligned; torsional stick–slip is managed mainly through the drilling parameters.

• Impact and vibration are transmitted directly to the drill string and the rig.
• Drill rods, threads and couplings fail more often from fatigue.
• The rotary head, gearbox, feed system and bearings wear faster or get damaged.
• Bit and hammer life is shorter, raising consumable costs.
• Penetration rates drop.
• Maintenance, downtime and operating costs go up.
• Noise and operator fatigue increase.

In short: lower drilling efficiency, faster equipment wear and higher overall cost.

Frequent rod or thread breakage, excessive vibration and noise, bit bounce, or recurring damage to the rotary head and other rig components are strong signs. Send us your rig model and our engineers will recommend the right model.

Choose by your rig's pulldown:

• SC25 — up to 30,000 lbf
• SC50 — 25,000 to 55,000 lbf
• SC75 — 50,000 to 80,000 lbf
• SC100 — 80,000 to 110,000 lbf

Send us your rig model, rotary head thread and shaft diameter, and our engineers will confirm the model and threads. See the full specifications and compatible rigs.

Samavich shock absorbers are maintenance-free: a rugged, sealed construction designed to run for at least six months without upkeep, depending on mine conditions. A quick visual check of the threads and housing during your routine rig inspections is all we recommend.

Service life depends on the drilling conditions — rock hardness, rig pulldown, hammer air pressure in DTH work, and choosing the right model. Under normal conditions the design runs for at least six months without upkeep. Correct model selection and routine inspections help it last longer.

Running above a model's rated pulldown reduces its effectiveness and can cause premature wear or failure. Selecting the right model and keeping the drilling parameters within its range is essential for safe, reliable operation.

An optional mechanical clamp connection, available on every SC model. Clamp halves lock the top and bottom subs to the absorber, removing welding at the rotary head bull shaft and the top adapter — no heat-affected zones, quick reversible assembly and no hot work on site. See how it works.