PG30 30×30 mm Four Slot Aluminium Strut Profile Standard Wall Column

OEM / ODM Available Free Sample Available ISO 9001:2015 EN 755-9 RoHS REACH

A 30 x 30 mm four slot standard wall PG30 aluminium strut profile square column. For guard frames, small enclosures and secondary framing, with M6 hardware throughout.

Wholesale Price $2.30 - $3.60 / m per m

Material	Aluminium
Alloy Grade	6063-T5
Temper	T5
Section Size	30 x 30 mm
Slot	4 x 8.2 mm groove, 6 mm mouth, 30 mm pitch, 1 slot per face, M6
Length	6 m stock, cut to drawing to +/-0.5 mm
Tolerance	EN 755-9 / GB/T 6892, wall +/-0.15 mm
Surface	Mill finish / clear anodised / black anodised
MOQ	400
Lead Time	18-28 days after deposit for mill finish
Loading Port	Shanghai / Ningbo
Supply Ability	450 t per month
Payment Terms	T/T 30% deposit + 70% before shipment \| L/C at sight
Trade Terms	FOB \| CIF \| EXW
Certifications	ISO 9001:2015 \| EN 755-9 \| RoHS \| REACH

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Structural framing · PG30 square column

A PG30 30 x 30 mm four slot aluminium strut profile is a square column section on the 30 series groove system. Four 8.2 mm grooves with a 6 mm mouth are cut on a 30 mm pitch, one on each face. The corners carry 4.5 mm bores taking M6 and the centre carries a 10 mm bore tapped M12 at the end. It weighs about 1.15 kg/m and is supplied in 6063-T5.

The 30 x 30 is the smallest section in the range that can be called a column rather than a frame member, and it comes with the one limitation that catches almost everyone who builds a frame from T-slot profile for the first time. Four slot mouths cut the outer surface into four separate strips, and separate strips are very poor at resisting twist. The section is fine in bending; it is the frame’s resistance to racking that has to be designed separately.

30 x 30 four slot section: one 8.2 mm groove per face on a 30 mm pitch, with a 10 mm centre bore and M6 corner bores.

Closed sections and open sections behave differently

Bending and torsion are carried by completely different parts of a section, and this is where most T-slot frames get their first surprise.

Bending is carried by material at the extremes of the section — the flanges. That is why a T-slot profile is good in bending: its flanges are exactly where they need to be, and the 30 x 30 section has about 3 cm4 about both axes.

Torsion is carried by a closed loop. A tube resists twist because the shear flows round a continuous ring of material. Cut that ring anywhere and the shear has nowhere to flow, so the section stops behaving like a tube and starts behaving like a bundle of flat strips, which is dramatically weaker.

Section form	Torsional constant	Relative	Comment
Closed box, 30 x 30, 2.2 mm wall	approx. 47 cm4	110 x	Shear flows round a continuous ring
T-slot profile, four 6 mm slot mouths	Between the two, nearer the box	Well below 110 x	The mouth is narrow, so much of the ring survives
The same section cut fully open along one length	approx. 0.43 cm4	Reference	Shear can only run along the wall thickness

A single lengthways cut turns a tube into a bundle of strips. On the calculation above the torsional constant falls by a factor of about a hundred. A T-slot profile is not cut fully open — the 6 mm mouth leaves most of the ring intact — but it is far enough from a closed box that torsion has to be designed for rather than assumed.

What this means for a bolted frame

A frame made of bolted T-slot profiles has two sources of flexibility: the sections themselves, and the joints. In bending the sections dominate, and the frame is usually fine. In torsion the joints dominate, because a bolted joint in a groove is not rigid in rotation — it can slip a fraction of a millimetre before the friction is overcome.

That is why a bolted T-slot frame racks even when the sections are generously sized. Push the top of the frame sideways and the rectangle becomes a parallelogram, not because anything has broken but because each of the four corners has rotated slightly. Stepping up from a 30 x 30 to a 45 x 45 section makes the members stiffer and does very little for the racking.

Fix	Effect on racking	Cost	When to use it
Step up a section size	Small	High, on every member	Only if bending is also a problem
Diagonal brace in one plane	Large	Low, one member and two brackets	Almost always the right first answer
Panel fixed to one face	Large, if it is a real panel	Low, and it may be needed anyway	Guards, enclosures, machine covers
Gusset plate at each corner	Moderate	Low	Where a brace would obstruct
Corner bracket with a wide footprint	Moderate	Low	Standard practice, better than a narrow bracket
Bolting the frame to a rigid floor or wall	Large	Site work	Where the frame is fixed down anyway

The 30 series limits

The 30 series groove is 8.2 mm wide with a 6 mm mouth, which takes M6 slot nuts and M6 T-bolts. The corner bores are 4.5 mm for M6 clearance and the centre bore is 10 mm, tapped M12 at the end. Those three sizes set the section’s ceiling, and they are worth knowing before the design is fixed.

Feature	Size	What it takes	What it will not take
Slot groove	8.2 mm, 6 mm mouth	M6 slot nuts and T-bolts	M8 hardware, which needs the 40 series
Corner bores	4.5 mm	M6 clearance bolts	M8 clearance
Centre bore	10 mm	M12 tap, or M12 threaded bar	M14 or larger
Slot torque ceiling	About 8 to 10 N m for M6	Normal assembly torque	Heavy clamping loads
Section stiffness	About 3 cm4	Short spans and light loads	Long unbraced spans

The section is at its best in machine guards, small enclosures, sensor mounts, light workstations and display frames, and in any structure where the members are short and the loads are measured in tens of kilograms rather than tonnes. It is also widely used as the secondary framing inside a heavier 40 or 45 series frame, where it carries panels rather than structural load.

Right for the 30 x 30Guard frames, small enclosures, sensor and light mounts, display frames, secondary framing inside a heavier frame, and short braced members.

Wrong for the 30 x 30Unbraced posts over about 1.5 m, anything requiring M8 hardware, any frame where racking has to be resisted by the sections alone, and any member that carries a person or a machine.

Frequently asked questions

Why does my 30 x 30 frame rack?

Because the sections are cut into four strips by the slot mouths, so they are much weaker in torsion than a closed tube, and because bolted joints in a groove are not rigid in rotation. Both effects are normal. The fix is a diagonal brace or a panel, not a bigger section.

Will a larger section fix the racking?

Not much. Racking is dominated by rotation at the joints, and the joints do not become rigid just because the members are stiffer. A brace or a panel is the answer, and it costs a fraction of stepping up every member in the frame.

What hardware fits the 30 series?

M6 slot nuts and M6 T-bolts in the 8.2 mm groove with its 6 mm mouth, and M6 bolts through the 4.5 mm corner bores. The 10 mm centre bore takes an M12 tap. M8 hardware needs the 40 series.

How tall can a 30 x 30 post be?

Keep unbraced posts under about 1.5 m. Beyond that the section buckles at a low load and the frame becomes wobbly. For anything taller, brace it or step up to the 40 series.

What is the slot pitch for?

30 mm, which is the 30 series accessory pitch. One slot per face on this section means the mounting positions are on the face centre lines, with the slot centres 23 mm apart across each corner.

Send the frame size and whether it has to resist racking

Tell us the frame size, the load and whether the frame has to stay square under a sideways push. We will quote the brace and the brackets alongside the profile rather than selling you a heavier section.

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