Central bolt for end connection

AL Modular System · Connection elements

Central bolt for end connection

It is the simplest and most economical connection between two strut profiles: the profile arriving end-on is fixed to the side of the other with a single screw in the central bore. The self-tapping versions S6x16, S8x25 and S12x30 form their own thread, so you do not need to tap; the M12x30 requires an M12 thread in the central bore but holds more. It is tightened with the Torx offset screwdriver of the right size.

Slot C6 · C8 · C10Self-tapping or M12Up to 3000 NTorx T25 · T40 · T50Zinc-plated steel

Why choose it

Minimal connection

One screw per joint: no visible brackets when the load is moderate.

Self-tapping

S6, S8 and S12 form the thread in the central bore: no need to tap the profile.

M12 for more load capacity

With the M12 thread in the central bore you reach 3000 N.

Data and compatibility

Property	Value
Slot	C6 · C8 · C10
Versions	S6x16-T25 (C6) · S8x25-T40 (C8) · S12x30-T50 e M12x30-T50 (C10)
Material	Zinc-plated steel
Load capacity Fmax	S6: 500 N · S8: 800 N · S12: 1300 N · M12: 3000 N
Moment Mmax	S6: 8 N·m · S8: 43 N·m · S12 e M12: 80 N·m
Tightening torque	S6: 10 N·m · S8: 25 N·m · S12 e M12: 35 N·m
Profile machining	Self-tapping: no tapping · M12: M12 thread in the central bore
Tool	Torx offset screwdriver T25, T40 or T50
Through hole for screwdriver	Ø 5.8 mm (S6) · 7.8 mm (S8) · 9.8 mm (S12, M12), if needed
Versions	4 codes

Choose the variant above: data and code update in the Specifications tab.

Related products

Anti-torsion element for central boltAnti-torsion element for C8 and C10

Aluminium strut profile 30x30Profile 30x30, slot C8

Aluminium strut profile 45x45Profile 45x45, slot C10

Aluminium strut profile 20x20Profile 20x20, slot C6

Any other questions?Read the 16 FAQs →

Need help with your profile parts list?

Send us a sketch or the parts list: we will give you codes, accessories and cut lengths.

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Specifications

Slot	C8
ESD	yes
Surface treatment	Zinc plating
Load capacity Fmax N	800
Moment Mmax Nm	43
Tightening torque Nm	25
Production method	Moulding
Technical notes	Vite centrale autoformante S8x25-T40
Diameter mm	10.7
Thread	M8
Length mm	25
Material	Zinc-plated steel
Type	Self-tapping
Brand	Bosch Rexroth

Tags
Tags	Bosch 5SP

When you join two profiles end to end with the central bolt or a quick connector and the connection must withstand moments that would rotate the profile, for example a side-loaded cross member.

The S12x30 is fitted without tapping the central bore and holds 1300 N. The M12x30 requires an M12 thread in the central bore, but carries 3000 N with the same maximum moment (80 N·m). Choose the M12 when the connection works in tension.

The one for the central bolt: T25 for the S6x16 of profiles with slot C6, T40 for the S8x25 with slot C8, T50 for S12x30 and M12x30 with slot C10.

With a single central bolt, yes, if the moment is high. To lock it, add the anti-torsion element for slot C8 or C10: it increases torsional resistance and can also be fitted after the connection has been made.

With T-joints made with a central bolt or quick connector, on the butting profile. Observe the hole distance from the end of the profile specified for the connection.

In connections with a central bolt on closed profiles, where you drill a through hole to reach the screw with the angle key. The cover cap closes the hole once assembly is complete.

For screws with a Torx T50 recess, such as the S12x30 and M12x30 central bolts of profiles with slot C10. The ball end helps when you cannot reach the screw in line.

With the Torx offset screwdriver: T25 for the S6, T40 for the S8, T50 for S12 and M12. If you need to use a straight screwdriver, a through hole in the profile is required (Ø 5.8, 7.8 or 9.8 mm), which you can close again with a plug.

It is the width of the profile slot and determines which accessories you use. Slot C6 (6 mm) is for 20 series profiles, C8 (8 mm) for the 30 series, C10 (10 mm) for profiles from the 40 series upwards. Nuts, screws, brackets and cover caps are chosen by slot: each accessory's product page shows the right one.

Yes. You can order the full bar or the piece cut to the length you need: we do the cutting ourselves, in our workshop. Each profile's product page shows the maximum bar length and the minimum cut length.

Look at the moments of inertia Ix and Iy: the higher they are, the less the profile deflects under load. For the same section, “L” profiles are lightened and deflect a little more. For long spans or high loads move to a larger section or a tall profile (e.g. 45x90 instead of 45x45). If you send us drawing and loads, we will check the choice.

The T-nut is inserted from the front into the slot, even in an assembled structure, and positions itself when you tighten the screw: it is the standard choice for fixing accessories. The sliding block withstands higher forces, but normally has to be inserted from the profile end before closing the frame; spring versions stay where you put them.

The simplest way is the bracket, which joins two profiles at 90° with screws and nuts in the slot, without machining. For end, T, 45° or three-way connections there are dedicated connectors, some of which require profile machining as stated on their product page.

Yes, for several accessories (for example cover caps, hinges and nuts) there are conductive ESD versions, indicated in the name or variant. Tell us which EPA area you work in and we will confirm the components to use.

On each product page you will find the MGE catalogue pages to download as PDF, with dimensioned drawings and technical data; the Specifications tab shows the data for the variant you have chosen.

Yes. Send us the parts list or a sketch with dimensions: we give you codes, quantities and cut lengths and prepare the kit with profiles already cut and the accessories.