What Is an M4 x 0.7 screw? A Complete Guide to Size and Thread Pitch

Why do so many M4 fastener batches fail field assembly, even when the diameter looks correct?

The answer is almost always incorrect or unspecified thread pitch.

M4 x 0.7 screw is a common Metric screw specification used in machinery, electronics, home appliances, and industrial OEM assemblies. Compliant with standard ISO metric specifications, M4 refers to the 4 mm nominal thread diameter, while 0.7 defines a 0.7 mm thread pitch.

For procurement staff and on-site engineers, mastering this basic spec eliminates thread stripping, unplanned batch rework, and unnecessary production downtime caused by incompatible threading.

What Are the Dimensions of an M4 x 0.7 screw?

Thread specification and full screw dimensions are separate values. M4 x 0.7 only describes the thread profile. It does not define head shape or total fastener length.

Key dimensions to review for every M4 x 0.7 screw:

• Nominal diameter
• Thread pitch
• Thread length
• Head diameter
• Head height
• Overall screw length

Two fasteners can both carry M4 x 0.7 thread while using pan heads, socket heads or countersunk heads and different body lengths. Always confirm head geometry and length separately for your assembly.

Hongyuan Fastener manufactures M4 x 0.7 screws and other Metric screws according to standard specifications or OEM requirements. For drawing-based projects, additional dimensions such as screw length, head geometry, thread length, and tolerance can be specified according to the customer’s design.

What Is the Thread Pitch of an M4 x 0.7 screw?

The thread pitch of an M4 x 0.7 screw is 0.7 mm.

This means the axial distance between adjacent corresponding thread points is 0.7 mm.

Pitch affects the spacing and density of the threads:

• A smaller pitch means more threads over a given length.
• A larger pitch means fewer threads over the same length.
• Different pitches can affect thread engagement and assembly characteristics.

This is the reason two screws marked “M4” may not work together. M4 supports both coarse pitch M4 x 0.7 and fine pitch M4 × 0.5. Their threads will not mate even though nominal diameter stays 4 mm.

Is M4 x 0.7 the Same as an M4 Screw?

They are not fully interchangeable. “M4” alone only tells buyers the nominal diameter. M4 x 0.7 adds the pitch value to lock in the exact thread profile.

Specification	Meaning
M4	4 mm nominal diameter, pitch not specified
M4 × 0.7	4 mm nominal diameter + 0.7 mm coarse pitch

Diameter matching alone cannot guarantee compatible threads. If pitch differs, internal and external threads will bind or strip during assembly. Never place orders using only “M4 screw” on your BOM or purchase order.

What Is the Correct Hole Size for an M4 x 0.7 screw?

Two hole types apply to M4 x 0.7 installations, and they serve different assembly purposes.

Clearance Hole

Use a clearance hole when the screw passes fully through the workpiece and fastens with a nut. A typical medium clearance hole for M4 x 0.7 measures 4.5 mm. This keeps the screw free to rotate during tightening.

Tapped Hole

A tapped hole requires pre-drilling before cutting internal threads. The standard tap drill size for M4 x 0.7 is 3.3 mm.

But the appropriate drill size can vary with the required thread percentage, material, tapping method, and engineering standard.

How Do You Identify an M4 x 0.7 Screw?

You can verify thread specs on incoming parts using this practical inspection workflow:

1. Measure the outer thread diameter with calipers.
2. Measure the distance between adjacent thread crests to calculate pitch.
3. Confirm the thread profile follows metric geometry.
4. Validate pitch with a metric thread gauge.
5. Cross-check results against your engineering drawing or standard specification sheet.

Visual inspection alone is not reliable. M4 x 0.5 and M4 x 0.7 look very similar to the naked eye.

How Should You Specify an M4 x 0.7 Screw When Ordering?

The thread marking M4 x 0.7 forms just one part of a complete fastener callout. Your purchase order needs all these details:

• Screw length
• Head type
• Drive type
• Material grade
• Surface finish
• Thread length
• Thread tolerance class
• Applicable industry standard
• Drawing requirements, if custom geometry is needed

For example: M4 x 0.7 x 20 mm, stainless steel, pan head, Phillips drive

Custom M4 x 0.7 Screws for OEM Applications

Standard M4 x 0.7 fasteners cover most general assembly jobs. Some OEM projects need modified variants to fit unique enclosure, fixture or machine designs.

Custom options include non-standard shank lengths, special head profiles, bespoke drive recesses, tight thread tolerances, specialty alloys, custom plating and modified under-head structures.

Hongyuan Fastener produces standard and custom metric fasteners for OEM and industrial customers. Send your drawing or assembly requirements, and our technical team will review your M4 × 0.7 screw specs and provide matched samples and project pricing.

What Should You Remember About M4 x 0.7 Screws?

M4 x 0.7 is a Metric thread designation, where M4 indicates a 4 mm nominal thread diameter and 0.7 indicates a 0.7 mm pitch. It does not define the complete screw size or configuration.

When purchasing or specifying an M4 x 0.7 screw, buyers should also consider the screw length, head type, drive, material, thread length, tolerance, and other application requirements. For tapped holes, the internal thread must also match the screw’s thread specification.

For standard requirements, an existing M4 x 0.7 screw specification may be sufficient. For OEM projects requiring special dimensions or configurations, Hongyuan Fastener can manufacture M4 × 0.7 and other screws based on drawings or samples.