Threaded Inserts · DIN 8140

M8 Helical Thread Inserts Dimensions & Specifications

The M8 size of Helical Thread Inserts is dimensioned by DIN 8140. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.

M8 Dimensional Row (DIN 8140)

Thread size	Pitch (mm)	Length (mm)	Drill / tap size (mm)	Free coil diameter (mm)	Reference standard	Notes
M8	1.25	12.0	8.4 (STI tap)	9.01	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off

Spanner & Drive for M8 Helical Thread Inserts

Drive geometry for M8 Helical Thread Inserts is given by the row above; match the tool to the listed values.

Common Applications for M8 Helical Thread Inserts

M8 Helical Thread Inserts are commonly specified for general engineering applications.

When to Step Up or Down from M8

When the joint preload approaches the proof load of M8 class 8.8, step up to M10 class 8.8 (or move to M8 class 10.9). When the joint is over-specified, M6 often saves weight and cost without losing the safety margin.

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

Request a Quote

Adjust the parameters in the drawing above and click "Request this configuration" to send the exact specification straight to this form.

Category Type Standard Thread size Material Finish

Dimensions & Specifications (DIN 8140)

Thread size	Pitch (mm)	Length (mm)	Drill / tap size (mm)	Free coil diameter (mm)	Reference standard	Notes
M3	0.5	4.5	3.1 (STI tap)	3.45	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M3	0.5	6.0	3.1 (STI tap)	3.45	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M4	0.7	6.0	4.2 (STI tap)	4.57	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M4	0.7	8.0	4.2 (STI tap)	4.57	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M5	0.8	7.5	5.3 (STI tap)	5.67	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M5	0.8	10.0	5.3 (STI tap)	5.67	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M6	1.0	9.0	6.3 (STI tap)	6.80	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M6	1.0	12.0	6.3 (STI tap)	6.80	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M8	1.25	12.0	8.4 (STI tap)	9.01	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M8	1.25	16.0	8.4 (STI tap)	9.01	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M10	1.5	15.0	10.5 (STI tap)	11.26	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M10	1.5	20.0	10.5 (STI tap)	11.26	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M12	1.75	18.0	12.6 (STI tap)	13.51	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M12	1.75	24.0	12.6 (STI tap)	13.51	DIN 8140 / ISO 10130	Wire thread insert, 2xD length; tang break-off
M16	2.0	24.0	16.5 (STI tap)	17.71	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off
M20	2.5	30.0	20.5 (STI tap)	22.07	DIN 8140 / ISO 10130	Wire thread insert, 1.5xD length; tang break-off

Frequently Asked Questions

What clearance and tapping drill suit M8?

Use a 9 mm clearance hole (ISO 273 medium) for through-fixing, or a 6.8 mm tapping drill for a coarse M8 thread.

What is the coarse-thread pitch of M8 for Helical Thread Inserts?

For M8 the standard coarse pitch is 1.25 mm — this is the value used for Helical Thread Inserts.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.