Controlling dimensions to Trade series (cross dowel nuts), with spanner or drive size and tightening torque.
M8 Cross Dowel Furniture Nuts dimensions to Trade series (cross dowel nuts): coarse thread pitch 1.25 mm. Tighten to approximately 25 Nm at property class 8.8 in a dry, as-supplied condition.
Coarse thread pitch
1.25 mm
Tightening torque (class 8.8)
25 Nm
Figures are nominal values from the governing standard. Confirm against the tolerance class for your application before machining or ordering.
Hidden Deck Fasteners Sourcing: Manufacturing, Types & Material Compatibility
M8 Cross Dowel Furniture Nuts are manufactured to Trade series (cross dowel nuts). This page lists the controlling dimensions for the M8 size together with the drive and the installation notes for this type.
Values are taken from the governing standard rather than from a general machine-thread table, because this type is not selected on one.
M8 Dimensional Row (Trade series (cross dowel nuts))
Thread size
Diameter options (mm)
Length options (mm)
Body form
Material options
M8
10~12
22~60
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
Spanner & Drive for M8 Cross Dowel Furniture Nuts
Drive geometry for M8 Cross Dowel Furniture Nuts is given by the row above; match the tool to the listed values.
Tightening Torque for M8
Class 8.8 (dry, ~µ 0.125)
≈ 25 Nm
Class 10.9 (dry, ~µ 0.125)
≈ 35 Nm
Class 12.9 (dry, ~µ 0.125)
≈ 41 Nm
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M8
Tensile stress area As (ISO 898-1)
36.6 mm²
Proof load, class 8.8
21 kN
Proof load, class 10.9
30 kN
Proof load, class 12.9
36 kN
Min. ultimate tensile, class 8.8
29 kN
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
Mating Parts for M8
Pair M8 with the matching M8 bolt or screw, plus a M8 flat washer where required to distribute load on softer materials.
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
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Dimensions & Specifications (Trade series (cross dowel nuts))
Thread size
Diameter options (mm)
Length options (mm)
Body form
Material options
M4
6
15
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M5
8
18
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M6
8 or 9
19
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M8
10~12
22~60
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M10
12~16
20~50
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
Materials & Grades
Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.
Flat-pack furnitureCross dowel nuts clamp panels where the bolt enters perpendicular to the barrel.
Cabinet productionGalvanized and stainless barrels provide a hidden threaded joint.
Machine building & OEMThe clamping counter-face on studs and bolts throughout an assembly.
Steel fabricationBolted structural and frame connections.
Typical applications
selecting a length that fits the blind bore
using galvanized steel or 1.4305 stainless
aligning a cross-drilled barrel with a mating bolt
choosing M4 through M10 and the barrel diameter
locking an adjustment so it cannot drift
joints re-torqued at a service interval
Service conditions to specify against
Marine and coastal
Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
High load
Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
Exterior structural
Hot-dip galvanised options for external steelwork; allow for the thicker coating in the mating thread.
Match the class
A nut below the bolt property class strips before the bolt reaches its own limit — pair class 8 nuts with 8.8 bolts, class 10 with 10.9.
Where to use something else
Do not drill the cross bore from the visible face without a positioning jig; misalignment prevents the bolt from entering.
Need help matching Cross Dowel Furniture Nuts to your application? Send the assembly, the load and the environment with your enquiry and we will specify the size, material and finish against them.
Inside the plant
Manufactured in our own plant
This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.
01
Cold heading
Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.
Head dimensions and under-head radius checked at set-up and per shift.
02
Thread rolling
Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.
Go / no-go ring gauges to ISO 965 tolerance class 6g.
03
Heat treatment
Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.
Core hardness and tensile tested per lot to ISO 898-1.
04
Surface treatment
Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.
Coating thickness and neutral salt spray hours to ISO 9227.
Frequently Asked Questions
What is the coarse-thread pitch of M8 for Cross Dowel Furniture Nuts?
For M8 the standard coarse pitch is 1.25 mm — this is the value used for Cross Dowel Furniture Nuts.
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 height of an M8 nut?
The nominal height of a style-1 ISO 4032 M8 nut is in the spec table on this page. Style-2 (thick) is approximately 1.1× this height; thin (ISO 4035 / DIN 439) is approximately 0.5×.
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.
Need a fastener quote or a spec sheet?Message our engineers on WhatsApp — send a drawing or DIN number and get pricing back fast.Start WhatsApp Chat →
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