Metric Bolt Head Wrench Size

Reference data and engineering information about metric bolt head wrench size for miscellaneous applications.

metricboltheadwrench

Overview

Engineering reference data for Metric Bolt Head Wrench Size in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Detailed Wrench Size Data

8 rows

Standard metric bolt sizes and their corresponding wrench/spanner sizes across different standards.
Bolt Size(mm)	ANSI/ISO Wrench(mm)	DIN Wrench(mm)	JIS Wrench(mm)	Allen Key(mm)
3	5.5
4	7	7	7
5	8	8	8	4
6	10	10	10	5
7		11
8	13	13	12	6
10	15, 16	17	14	8
12	18	19	17	10

Source: engineeringtoolbox.com

This table references the following key engineering standards:

ANSI B18.2.3.9M: Metric Heavy Hex Flange Screws
*ISO 4228: Spanners and wrenches -- Spline drive ends for power socket wrenches
*ISO 724: Metric Threads

Definition: An Allen key, Allen wrench, or hex key is a simple hand tool used to drive bolts and screws that have a hexagonal socket (recess) in their head.

Interactive Charts

Bolt Stretching and Tensile Stress

References

Original Source

Source: engineeringtoolbox.com