Product Description
The 90 mm N3 low-pressure DTH bit is intended for mining engineering, quarry holes, and competent construction rock with an N3 impactor system. Its 3.54-inch gauge fits a compact DTH class where the hammer and compressor are selected for low-pressure operation. Review the job in the mining and exploration application archive and compare the rock with the hard formation archive. The tool should not be used to claim that low pressure alone will stabilize loose or broken overburden.
The source identifies an N3 impactor, 90 mm gauge, low-air-pressure service, and wear-resistant DTH construction. The record uses an alloy-steel DTH body with fixed carbide buttons and an N3 shank family. Button count, face type, retaining arrangement, foot valve, and port area are not supplied. “High efficiency” and “wear resistance” remain source descriptors rather than quantified performance. Confirm the hammer drawing, shank dimensions, valve configuration, and actual face before the bit is matched to an N3 system.
Use 1,000–3,000 lbf/in of diameter and 25–60 RPM, with pressure and air volume controlled by the verified N3 hammer instructions. The broader DTH reference is 0.7–2.4 MPa, but low-pressure labeling does not authorize choosing a value without the hammer data. Hard and abrasive rock are suitable; broken ground needs conservative loading. Measure pressure at the hammer when possible because surface readings include line losses. Flow is blank because delivered air volume is not stated. The limitation is missing N3 dimensional and pneumatic detail. Drilling references can be reviewed through the IADC.
