Drill Rod Tolerance

The table below shows the standard dimensional drill rod tolerance adopted by the US manufacturers. It shows the deviation from a nominal diameter. The diameter tolerance varies by size and whether the nominal diameter dimension is in inches or millimeters.

Drill Rod Tolerance Table

Material Type Diameter Tolerance
Tool Steel
0.000 – 0.124″ ±.0003″
0.125 – 0.499″ ±.0005″
0.0010″ + ±.0010″
0-3mm ±.008mm
4-12mm ±.013mm
13mm + ±.025mm


The table below shows the length and straightness tolerances of drill rod as it depend on whether the dimensions are inches or millimeters. The straightness tolerance is reported in T.I.R. which is an abbreviation for total indicator reading.

Drill Rod Straightness Tolerance Table

Material Type Length Tolerance Straightness
Tool Steel
36″ +0/+0.125″ ±.005″ max T.I.R. per 12″
915mm -0.60/+2.60mm ±.13mm max T.I.R. per 300mm