Aluminium Profile Machine Guard Frame 40 x 40 mm Safety Enclosure

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

40 x 40 mm T-slot aluminium machine guard frame for safety fences and enclosures, built to ISO 14120 principles with mesh or polycarbonate infill.

Wholesale Price Quoted against dimensions, infill and door hardware per per frame

Material	Aluminium
Alloy Grade	6063-T5
Temper	T5
Section Size	40 x 40 mm post and rail
Slot	8 mm groove, M6 and M8 slot nuts, 30 mm slot centres across the corner
Length	Cut to drawing, post and rail to +/-0.5 mm
Tolerance	EN 755-9, wall +/-0.15 mm
Surface	Mill finish / clear anodised / black anodised
MOQ	Made to order; single frames from stock components
Lead Time	Typically 2 to 3 weeks for the cut and machined frame, plus a week for anodising
Loading Port	Shanghai, Ningbo, Qingdao
Supply Ability	In-house cutting, machining and assembly capacity for guard frames
Payment Terms	T/T 30 per cent deposit, balance against copy of bill of lading
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 an aluminium machine guard frame?

Is a guard frame just a fence?

No. A guard is a safety device, not a fence. It must keep an operator’s hand or body part from reaching a hazard, which is a dimensional requirement set out in ISO 14120. The aluminium frame is the structural part; the mesh or panel infill and the door interlocks are what actually make it a guard.

What is ISO 14120?

It is the standard for the design of machine guards. The key principle is that the guard must prevent access to the hazard, which means the openings must be small enough, and the distance between the guard and the hazard large enough, that a hand or finger cannot reach through. Section 04 gives the opening sizes.

Why aluminium T-slot rather than welded steel?

Aluminium T-slot goes together without welding and without heat, so it is faster to build and easy to modify when the machine changes. It is lighter than steel, does not rust, and the slots carry the mesh or panels directly. The trade is that aluminium is softer than steel, so the frame must be sized for the expected impact.

02Frame data

Item	Value	Note
Post and rail	40 x 40 mm	40 series T-slot
Groove	8 mm	30 mm slot centres across the corner
Fixings	M6 and M8 slot nuts	mesh clips and panel retainers
Wall	light / standard / heavy	weight 1.30 to 2.35 kg/m
Infill	mesh or polycarbonate	in the slot or a panel retainer
Doors	hinged, with interlock	switch wired to the safety circuit
Alloy	6063-T5	EN AW-6063
Standard	ISO 14120	guard design principles

03The four jobs a guard does

A machine guard does four things at once, and each one drives part of the design.

Contain the hazard: the infill and frame keep fingers, hands and tools away from moving parts.
Absorb a light impact: if a part is ejected or an operator leans on the guard, the frame and infill must hold.
Allow visibility: the mesh or clear panel lets the operator see the process, so the guard does not have to be opened to watch it.
Control access: the hinged door with an interlock stops the machine when the guard is opened.

The frame is sized for the first two jobs; the infill and door are specified for the second two.

04ISO 14120 opening sizes and distances

The guard works by making the openings small enough that a hand cannot reach through to the hazard. ISO 14120 links the opening size to the minimum distance between the guard and the hazard.

Opening size (mm)	Min distance to hazard (mm)	Typical infill
up to 4	0	solid panel
4 to 8	15	fine mesh
8 to 25	120	standard mesh
25 to 40	200	coarse mesh
over 40	850 or more	not suitable for direct guarding

The distances are indicative and depend on the specific hazard. For a safety-critical guard, an engineer should verify the opening size and distance against the current ISO 14120 edition for the machine in question. This page is a design guide, not a certification.

05Impact and load the frame can take

The 40 x 40 mm frame is sized for light to medium impact. It will hold a mesh or polycarbonate panel and resist an operator leaning on it, but it is not a crash barrier.

Wall	Weight (kg/m)	Typical use
light	1.30	static guards, no impact expected
standard	1.8	guards with occasional contact or lean
heavy	2.35	guards near ejecting parts or moving loads

If the hazard can eject a part at high speed, the infill and frame must be engineered for that energy. In that case, a welded steel guard or a polycarbonate panel rated for the impact is usually the right answer.

06Aluminium T-slot vs welded steel guard

Choose aluminium T-slot

The guard must be built and modified quickly
No welding is available or wanted
The machine changes often and the guard must follow
Corrosion resistance matters (food, clean room)
Light weight matters for access and transport

Choose welded steel

The hazard can eject parts at speed
The guard must resist high impact
Fire resistance is required
The guard is permanent and rarely modified
Cost at scale favours welded steel for large enclosures

07Failure modes to design out

What goes wrong	Why it happens	Design it out by
Hand reaches through the opening	opening size or distance to hazard is wrong	verify opening and distance against ISO 14120 for the hazard
Door bypasses the interlock	the switch is not wired into the safety circuit	wire the interlock into the machine’s safety-rated stop circuit
Frame deforms on impact	the wall is too light for the expected impact	use the heavy wall near ejecting parts, or a welded steel guard
Mesh pulls out of the slot	the mesh clip is too light for the tension	use mesh retainers rated for the panel tension
Guard is removed and not replaced	the guard is awkward to open and operators bypass it	make the door hinged and counterbalanced so it is easy to use

08What to check before you order

Procurement checklist for the machine guard frame

Confirm the hazard: what the guard protects against, and the required opening size and distance per ISO 14120.
Confirm the frame wall: light, standard or heavy, based on the expected impact.
Confirm the infill: mesh or polycarbonate, and its panel size and rating.
Confirm the door: hinged or sliding, and whether an interlock switch is needed.
Confirm the fixings: M6 or M8 slot nuts for the mesh and panel retainers.
Confirm the dimensions and cut list for the post and rail frame.

09Terms used on this page

ISO 14120: The international standard for the design of machine guards, including the prevention of access to hazards.
Infill: The mesh or panel that fills the openings of the guard frame and blocks access.
Interlock: A switch on the guard door that stops the machine when the door opens.
Hazard: The moving part or energy source the guard protects against.
Opening size: The largest gap in the infill, which determines whether a hand or finger can reach through.

10Questions buyers ask

Does the guard frame meet ISO 14120?

The frame is designed to the principles of ISO 14120, but compliance is machine-specific. An engineer must verify the opening size, distance and interlock for the hazard in question. We build to your specification.

Can the frame carry a polycarbonate panel?

Yes. The panel sits in the slot or in a panel retainer, fixed with M6 or M8 slot nuts. Polycarbonate gives full visibility and better containment than mesh.

Is aluminium strong enough for a machine guard?

For light to medium impact, yes, when sized correctly. For hazards that can eject parts at speed, use the heavy wall or a welded steel guard.

Can I add a door later?

Yes. The T-slot system lets you add a hinged door and an interlock without rebuilding the frame.

What is the frame weight?

1.30 to 2.35 kg/m depending on the wall you select.

Can it be anodised?

Yes. Anodising is common for clean room and food environments, where the frame must be easy to clean.

What we need to quote the guard frame

The hazard description and the required opening size and distance.
The frame dimensions and the wall (light, standard or heavy).
The infill: mesh or polycarbonate, and its panel size and rating.
The door details: hinged or sliding, with or without interlock.
The finish: mill or anodised.
The quantity and any certification requirement.

Send those six items and the quotation comes back with the frame, infill, door hardware and finish broken out separately. Browse the full aluminium profile catalogue and the 40 series aluminium profiles range.

Need a machine guard frame quoted to your safety spec?

Send the hazard, dimensions, infill and door details. We quote the frame, infill and hardware as separate lines.

Request a quotation