number drill · nominal diameter

#53
drill bit size.

A #53 bit measures 0.0595 in across (1.511 mm).

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

Diameter conversion cross-checked

Calibrated relative diameter · 1 in reference

#53 · number

0.0595 in

1.511 mm

Designation#53number

Inch decimal0.0595nominal

Metric conversion1.511millimetres

Where this size sits from 0 to 1 inch

#53 · 1.511 mm on a zero to 25.4 millimetre scale. Neighbor marks: 1.5 mm, 1/16.

0 25.4 mm

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Where this bit is specified

What #53 is for.

#53 is the cutting-tap drill for the threads below— usually the reason this size gets looked up. Engagement is calculated from the basic 60° profile; open a thread for its published row, evidence, and limits.

Cutting-tap rows naming #53 CUT TAPS ONLY · CALCULATED ENGAGEMENT

#1-64 UNC UNC · manufacturer-published row 66.5% calculated thread engagement #1-72 UNF UNF · manufacturer-published row 74.8% calculated thread engagement

Measured neighbors

What sits beside #53.

“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

1.5 mmmetric 0.0591 inΔ -0.011 mm 1/16fractional 0.0625 inΔ +0.076 mm 1.6 mmmetric 0.0630 inΔ +0.089 mm 1.4 mmmetric 0.0551 inΔ -0.111 mm 1.7 mmmetric 0.0669 inΔ +0.189 mm

Same seriesNEAREST NOMINAL ROWS

#52number 1.613 mmΔ +0.102 mm #54number 1.397 mmΔ -0.114 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

#53drill bit size.

What #53 is for.

What sits beside #53.

ASME.

#53
drill bit size.