PG20 20 x 20 mm Four Slot Aluminium Strut Profile Miniature Frame

OEM / ODM Available Free Sample Available Mill certificate to EN 10204 3.1 on request, RoHS and REACH declarations

20 x 20 mm four-slot aluminium strut profile with 6.2 mm grooves and 6 mm mouths. The smallest standard four-slot section for miniature frames using M5 and M6 fasteners.

Wholesale Price Quoted per metre against section, finish and quantity per per metre

Material	Aluminium
Alloy Grade	6063-T5
Temper	T5
Section Size	20 x 20 mm
Slot	4 x 6.2 mm groove, 6 mm mouth, 20 mm pitch, 1 slot per face, M5 and 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	Made to order; small trial lengths available from stock offcuts
Lead Time	Typically 2 to 3 weeks for mill finish, about a week longer for anodising
Loading Port	Shanghai, Ningbo, Qingdao
Supply Ability	Extrusion capacity for standard and custom dies, with in-house cutting, machining and anodising
Payment Terms	T/T 30 per cent deposit, balance against copy of bill of lading; L/C at sight for larger orders
Trade Terms	FOB, CIF, CFR, EXW
Certifications	Mill certificate to EN 10204 3.1 on request, RoHS and REACH declarations

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01What is the 20 x 20 mm four slot profile?

What makes the 20 series the entry-level T-slot profile?

It is the smallest standard section that still gives you four T-slots, one on each face. The 6.2 mm groove and 6 mm mouth accept M5 and M6 slot nuts, which are the smallest practical sizes for aluminium frame assembly. Below this, you are in the 15 series with M4 fasteners, which is really only for display cases and very light panels.

How much load can a 20 x 20 frame carry?

Not much. The section weighs 0.62 kg/m, and the effective wall at the slot lip is about 1.5 mm. An M6 slot nut in a 6.2 mm groove has a rated pull-out of about 0.5 kN, roughly a third of what the same nut achieves in a 40 series groove. A 1 m simply supported beam deflects about 0.8 mm under a 50 N centre load. The 20 series is for instrument housings, cable trays and small guard panels, not for structural frames.

Can I upgrade from 20 series to 30 series later?

No, not without redesigning every joint. The 30 series has an 8.2 mm groove and 8 mm mouth, so 20 series nuts and bolts do not fit. The decision between 20 and 30 series has to be made at the design stage, based on the load and the fastener size the frame needs.

02Section data

Item	Value	Note
Envelope	20 x 20 mm square	smallest four-slot standard section
Slots	4	6.2 mm groove, 6 mm mouth, one per face
Slot pitch	20 mm between centres	across the diagonal
Central bore	approx. Phi4 mm	for through-bolts or location
Wall	approx. 1.5 mm at slot lip	thinnest point of the section
Weight	approx. 0.62 kg/m	from published specification
Alloy	6063-T5	EN AW-6063
Standard	EN 755-9 / GB/T 6892	wall tolerance +/-0.15 mm
Length	6 m stock	cut to drawing to +/-0.5 mm

The weight and wall figures are from the published product specification. The 1.5 mm wall at the slot lip is the thinnest point and drives the pull-out force rating. If a joint needs more tension, use the central bore with a through-bolt instead of the slots.

03Where the 20 series fits in the range

The 20 series is the bottom of the T-slot range. Below it is the 15 series (M4 fasteners, display only), and above it is the 30 series (M6/M8, light structural). The 20 series fills the gap where the frame is too small for 30 series but too functional for 15 series.

Instrument housings and sensor enclosures: the 20 x 20 is small enough to sit behind a panel, and the four slots give mounting on all sides.
Cable trays and wire routing frames: the 6.2 mm groove holds cable clips and cover strips, and the 0.62 kg/m weight keeps the frame negligible.
Small guard panels and access doors: where the guard is a barrier, not a load-bearing structure, and M5 fasteners are sufficient.
Prototype and jig frames: the 20 series is cheap enough to use for temporary fixtures and test rigs that will be dismantled.

In all these, the 20 series is chosen because the load is light and the space is tight. If either of those changes, the 30 series is the next step up.

04Fastener compatibility and slot pull-out

The 6.2 mm groove and 6 mm mouth accept the full 20 series accessory range: M5 and M6 slot nuts, hammer head T-bolts, cover strips, hinges and end caps. The slot nut grips the groove lips from behind, and the effective engagement length is the wall thickness at the lip, about 1.5 mm.

Fastener	Groove fit	Pull-out force	Typical torque
M5 slot nut	6.2 mm groove, snug	approx. 0.4 kN	2 to 3 Nm
M6 slot nut	6.2 mm groove, snug	approx. 0.5 kN	3 to 4 Nm
M5 T-bolt	6.2 mm groove, hammer head	approx. 0.4 kN	2 to 3 Nm
M6 T-bolt	6.2 mm groove, hammer head	approx. 0.5 kN	3 to 4 Nm
Through-bolt (central bore)	Phi4 mm bore	full bolt rating	as bolt spec

The pull-out figures are estimates based on the 1.5 mm wall at the slot lip. They are lower than the 30 and 40 series because the wall is thinner. For structural tension, use the central bore with a through-bolt.

05Bending performance and span limits

The 20 x 20 section has a second moment of area of about 0.2 cm4 about each principal axis. That is small, and it limits the span to short distances before deflection becomes unacceptable.

Span (mm)	Self-weight deflection	Deflection at 50 N centre load
300	negligible	0.07 mm
500	0.03 mm	0.20 mm
750	0.10 mm	0.45 mm
1000	0.24 mm	0.80 mm
1500	1.2 mm	2.7 mm

As a rule of thumb, a 20 x 20 member used as a beam should not span more than 500 mm without an intermediate support. For longer spans, step up to the 30 series or use a truss arrangement.

06Choosing between the 20 series and the 30 series

Choose the 20 series

The frame carries light loads: instruments, cables, small panels
Space is tight and the 20 mm envelope is the maximum
Weight matters: the 0.62 kg/m is lighter than the 30 series 0.7 kg/m
M5 fasteners are sufficient for the joint loads
The frame is temporary or prototype and cost is the driver

Choose the 30 series

The frame carries bending load or spans more than 500 mm
You need M6 or M8 fasteners for higher joint tension
Vibration resistance matters: the 30 series wall is thicker
The frame is permanent and needs more stiffness
You want the wider accessory range of the 30 series

07Failure modes to design out

What goes wrong	Why it happens	Design it out by
Slot nut pulls out under load	the 1.5 mm wall gives low engagement	use the central bore with a through-bolt for structural tension
Beam deflects too much	the second moment of area is only 0.2 cm4	keep spans under 500 mm or add an intermediate support
Frame racks under lateral load	the corner joints are weak with M5 fasteners	use corner brackets or gusset plates at every joint
Slot nut deforms the groove lip	overtightening an M6 nut in a 1.5 mm wall groove	keep torque under 4 Nm; use the through-bolt for higher clamping
Cover strip pops out	the 6 mm mouth is narrow and the strip clip is light	specify a friction-fit strip, not a snap-in strip, for the 20 series

08What to check before you order

Procurement checklist for the 20 x 20 four-slot

Confirm the fastener size: M5 or M6. If you need M8, step up to 30 or 40 series.
Confirm the span: any member over 500 mm needs an intermediate support or a bigger section.
Confirm the finish: mill for hidden frames, anodised for exposed service.
Confirm the quantity in metres. A 6 m bar yields twelve 480 mm members.
Confirm whether the central bore is needed. Not all 20 series dies have one.
If the frame carries lateral load, add corner brackets at every joint. M5 slot nuts alone will not prevent racking.

09Terms used on this page

Slot lip: The edge of the groove mouth that the slot nut grips from behind. Its thickness determines the pull-out force.
Pull-out force: The force required to pull a slot nut out of the groove. It is proportional to the wall thickness at the lip.
Second moment of area: A geometric property of the section, in cm4, that determines bending stiffness. The 20 x 20 has about 0.2 cm4.
Through-bolt: A bolt that passes through the central bore, tying two members together in tension. Independent of the slots.
Racking: The lateral deflection of a frame when a force is applied to one corner. Corner brackets resist racking.

10Questions buyers ask

Can I use M8 fasteners in the 20 series?

No. The 6.2 mm groove and 6 mm mouth are designed for M5 and M6 slot nuts. M8 nuts require the 8.2 mm groove of the 30 series or the 10.2 mm groove of the 40 series.

What is the maximum span for a 20 x 20 beam?

About 500 mm without an intermediate support. Beyond that, deflection under even modest load becomes noticeable. For longer spans, use the 30 series or add a support.

What is the difference between the 20 series and the 15 series?

The 15 series has a 6 mm groove and accepts M4 fasteners. It is for display cases and very light panels. The 20 series has a 6.2 mm groove, M5 and M6 fasteners, and four slots, making it the smallest practical section for functional frames.

What is the weight per metre?

Approximately 0.62 kg/m, from the published product specification.

Can it be supplied anodised?

Yes. Clear, black, champagne and bronze are standard anodised colours at 10 to 15 micron. Mill finish is available for hidden frames.

What is the lead time?

Typically two to three weeks for mill finish, with anodising adding about a week.

What we need to quote this section

The section drawing or the profile reference GP-SP-2020-4S.
The cut length for each member and the number of members.
The end preparation: square cut, mitre, or pre-drilled.
The finish: mill, clear anodised, or a specified colour.
The annual or per-order quantity, in metres or pieces.
Any certification requirement: mill certificate to EN 10204 3.1.

Send those six items and the quotation comes back with the extrusion price, the cutting charge, the finish surcharge and the lead time broken out separately. Browse the full aluminium profile catalogue and the 20 series aluminium profiles range for related sections.

Need this section quoted for your miniature frame?

Send the section, the cut list and the finish. We quote extrusion, cutting and anodising as separate lines so the cost of each step is visible.

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