letter drill · nominal diameter

K
drill bit size.

A K bit measures 0.2810 in across (7.137 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

K · letter

0.2810 in

7.137 mm

DesignationKletter

Inch decimal0.2810nominal

Metric conversion7.137millimetres

Where this size sits from 0 to 1 inch

K · 7.137 mm on a zero to 25.4 millimetre scale. Neighbor marks: 9/32, 7.1 mm.

0 25.4 mm

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Measured neighbors

What sits beside K.

“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

9/32fractional 0.2813 inΔ +0.006 mm 7.1 mmmetric 0.2795 inΔ -0.037 mm 7.2 mmmetric 0.2835 inΔ +0.063 mm 7 mmmetric 0.2756 inΔ -0.137 mm 7.3 mmmetric 0.2874 inΔ +0.163 mm

Same seriesNEAREST NOMINAL ROWS

Jletter 7.036 mmΔ -0.102 mm Lletter 7.366 mmΔ +0.229 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

Kdrill bit size.

What sits beside K.

ASME.

K
drill bit size.