SDS-PLUS Round Shank Electric Hammer Drill Bits (35x350)

A hammer bit makes a hole by smashing material and clearing the debris, and the volume it has to smash grows with the square of the diameter. Doubling the hole size does not double the work, it roughly quadruples it. At 35mm through a thick wall, on an SDS-PLUS machine, that is a slow and demanding job for the tool and for the person holding it, and it is close to the practical ceiling of the standard.

Where holes above this size are needed, the answer is a different method rather than a bigger bit. Diamond core drilling cuts an annular groove and removes a solid cylinder of material, so it only has to cut the ring rather than pulverise everything inside it. It is far faster at large diameters, it produces a clean accurate hole with no breakout, and with water suppression it makes very little dust. That is how large ventilation, soil pipe and duct penetrations are properly made. For a one off hole it is usually worth hiring the equipment or bringing in somebody who has it.

So buy this bit for occasional large penetrations and for work where a core rig cannot be set up, and know that regular large diameter work belongs to a different tool.

Thirty five millimetre holes take large pipework and duct penetrations, sleeved services, and heavy through bolts and anchors.

SDS-PLUS shank with a hammer grade carbide tip and double narrow land flutes, which at this diameter need clearing frequently since the dust volume is considerable.

Buyers are mechanical and electrical services contractors, plumbers, civil and building trades, and industrial maintenance.

Tell us the diameter and the wall on 94 77 111 8880 and we will give you a straight answer about whether to drill it or core it. We deliver island-wide.