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.

4mm → 1/4" Imperial

The nearest imperial equivalent of 4mm is 1/4" (2.35mm difference).

Result

Answer

1/4" (6.35mm)

Common

Buy4mm socket SAE conversion set Metric + SAE combo set

Input Size4mm

Nearest Imperial1/4" (6.35mm)

Difference2.35mm

Second Nearest5/16" (7.94mm, 3.94mm off)

SystemMetric → Imperial

A 4mm socket or wrench is closest to 1/4" imperial (6.35mm), a difference of 2.35mm. The gap is significant — using the imperial size risks rounding the fastener. Use the correct metric socket.

Note

The 2.35mm difference may cause the socket to slip or round the fastener head. Use the correct metric size whenever possible.

Related Sizes

5mm →

About 4mm Conversion

A 4mm metric socket or wrench is closest to 1/4" imperial (6.35mm), with a difference of 2.35mm. The gap between sizes is significant — using the imperial substitute risks rounding the fastener head. Always use the correct metric socket. The second-nearest imperial size is 5/16" (7.94mm, 3.94mm off). Small fasteners, electronics. When working on mixed metric and imperial fasteners, a combination socket set covers both systems and eliminates guesswork.

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