What sizes does this cover?

The Socket & Wrench Size pack covers standard metric hex bolts from M3 to M36 and imperial hex bolts from 1/4" to 1-1/2". These are the most common sizes in hardware stores and automotive work.

Are these sizes guaranteed correct?

Sizes are based on ISO and SAE standards for standard hex head bolts and nuts. Actual fasteners vary by manufacturer, grade, and application. Always verify with the fastener when precision matters.

What about Torx, spline, or specialty fasteners?

This tool covers hex head fasteners only. Torx, spline, 12-point, and other drive types are not yet supported.

Can I use the nearest imperial socket on a metric bolt?

In a pinch it may work, but risks rounding the fastener head. Use the correct socket whenever possible. Related values shown are for reference, not substitution.

Will more packs be added?

Yes. Pilot Hole, Tap Drill, and Metric/Imperial conversion packs are planned. The architecture supports new reference sets without changing the app.

M3 Bolt — 5.5mm Socket/Wrench

The standard socket size for an M3 hex bolt is 5.5mm. Nearest imperial equivalent: 7/32".

Result

Answer

5.5mm socket/wrench

Standard

Buy5.5mm socket metric socket set Pro metric set

Wrench/Socket Size5.5mm

Bolt Diameter3mm

Nearest Imperial Socket7/32"

Bolt SystemMetric (DIN/ISO)

A standard M3 hex bolt or nut uses a 5.5mm wrench or socket. The nearest imperial equivalent is a 7/32" socket, which may work in a pinch but is not an exact match.

Note

Reference value from published fastener data. Always verify with the fastener manufacturer for critical applications.

Related Sizes

M4 → 7mm →

About M3 Bolts

An M3 hex bolt has a 3mm shaft diameter and requires a 5.5mm socket or wrench to turn. This is a standard metric fastener size, widely used in automotive work, machinery, and general construction. The nearest imperial socket is 7/32" — it may work in an emergency, but the size difference risks rounding the bolt head. Always use the correct 5.5mm socket when possible.

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