letter drill · nominal diameter

G
drill bit size.

A G bit measures 0.2610 in across (6.629 mm).

The inch decimal is the published nominal designation; millimetres are a conversion.

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

G · letter

0.2610 in

6.629 mm

DesignationGletter

Inch decimal0.2610nominal

Metric conversion6.629millimetres

Where this size sits from 0 to 1 inch

G · 6.629 mm on a zero to 25.4 millimetre scale. Neighbor marks: 6.6 mm, 6.7 mm.

0 25.4 mm

Show calibrated outline Open in Finder

Measured neighbors

What sits beside G.

“Nearest” means nominal diameter only. It does not make a neighboring size acceptable for a tolerance, tapping, reaming, or fastener application.

Other naming systemsABSOLUTE DIAMETER DELTA

6.6 mmmetric 0.2598 inΔ -0.029 mm 6.7 mmmetric 0.2638 inΔ +0.071 mm 17/64fractional 0.2656 inΔ +0.117 mm 6.5 mmmetric 0.2559 inΔ -0.129 mm 6.8 mmmetric 0.2677 inΔ +0.171 mm

Same seriesNEAREST NOMINAL ROWS

Fletter 6.528 mmΔ -0.102 mm Hletter 6.756 mmΔ +0.127 mm

Source record

ASME.

The standard text is paywalled. Number and letter series are cross-checked against public manufacturer charts; exact standard edition/page verification remains a release gate.

Open source record

Gdrill bit size.

What sits beside G.

ASME.

G
drill bit size.