How to Choose the Right Piling Rig? Expert Selection & Torque Calculator

Most of the time contractor uses a rig which do not match the ground. It causes failures during boring, and results in delays, stuck drill strings, and other breakdown happen on-site. This online piling rig calculator calculator lets you input your project data in advance to get the data about torque, bore diameter, target depth, and formation type, and it recommends a rig class.

The formula this calculator applies

Required Torque (kNm) ≈ π/4 × D² (m) × Soil Resistance Factor × Depth Correction. Torque demand doesn’t scale linearly with diameter — going from 600mm to 1,200mm doesn’t just double the requirement, it roughly quadruples it, since torque scales with the diameter squared.

Rig Classification by Torque Output

Rig Class	Max Torque	Typical Application
Compact / Mini	30–80 kNm	Micro-piling, restricted access, soft soil up to 600 mm
Small	80–150 kNm	Shallow piles, soft-medium clay, up to 600 mm diameter
Medium	150–250 kNm	Standard building foundations, 600–1,000 mm, mixed formations
Large	250–400 kNm	Bridge piers, industrial plants, hard gravel, 1,000–1,500 mm
Heavy	400–600 kNm	Weathered rock, large diameter 1,200–2,000 mm
Super Heavy	600+ kNm	Hard rock, marine piling, diameter 2,000 mm+

The above selector tool would help the Civil Contractors, Foundation Engineers, and Piling Rig Rental Agencies to select the suitable rig machine as per thier requirements.