Miter Connector Model C 90 Degree Corner Joint for 40 mm Aluminium Profiles

OEM / ODM Available Free Sample Available RoHS declaration on request

Miter connector Model C for 90-degree corner joints on aluminium T-slot profiles. Internal tie rod, clean external corner. Available for 20, 30, 40 and 45 series.

Wholesale Price Quoted per piece against series, finish and quantity per per piece

Material	Zinc alloy housing / steel tie rod
Alloy Grade	Zamak zinc alloy / carbon steel
Temper	custom
Section Size	Fits 20 / 30 / 40 / 45 mm series profiles
Slot	Does not interact with slots; fits the centre bore
Length	Housing length varies by series; see data sheet
Tolerance	Housing to bore: H8/h7 sliding fit
Surface	Zinc plated / black zinc / nickel
MOQ	Stocked item; minimum 50 pieces per series
Lead Time	Typically 1 to 2 weeks for stocked series and finishes
Loading Port	Shanghai, Ningbo, Qingdao
Supply Ability	Die-cast and machined in-house; up to 100,000 pieces per month across all series
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	RoHS declaration on request

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Miter connector Model C 90 degree corner joint for aluminium profiles — The Model C miter connector joins two profiles at 90 degrees with an internal tie rod. The profile ends are cut square, and the external corner is clean with no visible bolts.

01What is a Miter Connector Model C?

What does the Model C miter connector do?

It joins two T-slot aluminium profiles end-to-end at a right angle (90 degrees) to form a corner. The connector sits inside the profiles: a zinc alloy housing goes into the centre bore of each profile, and a steel tie rod pulls the two halves together. The external corner is clean — no bolts, no brackets, no visible hardware — just two profile faces meeting at 90 degrees.

How is it different from the Model P?

The Model C cuts both profile ends square (90 degrees) and the corner has a right-angle external edge. The Model P cuts both ends at 45 degrees and the corner has a mitred (diagonal) external edge. The C model is simpler to cut (no angle) and gives a sharp, modern corner; the P model gives a softer, 45-degree corner that some designs prefer.

Why use an internal miter connector instead of an external bracket?

Three reasons. First, aesthetics: the corner is clean with no visible hardware, which matters in display frames, exhibition stands and customer-facing equipment. Second, strength: the internal tie rod pulls the joint together in tension, giving a stiffer corner than an external bracket that relies on slot nuts. Third, space: an internal connector does not protrude outside the profile envelope, so the frame fits into a smaller footprint.

Miter connector Model C — The Model C connector: a zinc alloy housing with an internal steel tie rod. Both profile ends are cut square, and the tie rod pulls them into a rigid 90-degree corner.

02How it works

The connector has three parts: a central housing (zinc alloy) that sits in the corner where the two profiles meet, a tie rod (steel) that runs through the housing and into the centre bore of one profile, and a threaded insert that goes into the centre bore of the other profile.

To assemble: slide the housing into the bore of the first profile, insert the threaded insert into the bore of the second profile, bring the two profiles together at 90 degrees, and tighten the tie rod. The rod pulls the two profiles against the housing, creating a rigid corner.

Part	Material	Function
Central housing	Zinc alloy (Zamak)	locates the corner, resists shear
Tie rod	Steel, zinc plated	pulls the two profiles together in tension
Threaded insert	Steel, zinc plated	receives the tie rod in the second profile
Set screw (some models)	Steel	locks the housing against rotation

03Profile preparation: the square cut

Both profile ends are cut square (90 degrees) — no angle cutting needed. This is the advantage of the Model C over the Model P: a square cut is faster, cheaper and easier to control than a 45-degree mitre cut.

The cut tolerance matters. The tie rod pulls the two profiles against the housing, so any gap or mismatch at the cut face shows up as a step or a gap at the external corner. Specify a cut tolerance of +/-0.5 mm on length and 0.5 degrees on squareness. For visible corners, a CNC cut saw is recommended; a manual chop saw is adequate for structural but not for aesthetic corners.

Cut parameter	Standard tolerance	Visible corner tolerance	Why
Length	+/-0.5 mm	+/-0.2 mm	a gap at the face shows as a visible line
Squareness	0.5 degrees	0.2 degrees	a tilt shows as a step at the corner
Burr	acceptable, filed	none	burr prevents flush contact
End finish	mill	mill or face-milled	a smoother face closes tighter

04Model C vs Model P: choosing the right corner

Choose Model C (90 degree square cut)

You want a sharp, modern right-angle corner
Cutting simplicity matters: square cuts are faster and cheaper
The corner will be hidden or clad, and appearance is secondary
You want the highest joint strength (the C housing is larger)
Production speed is important (no angle setup on the saw)

Choose Model P (45 degree mitre cut)

You want a softer, 45-degree diagonal corner
The corner is visible and aesthetic is the primary concern
You accept the additional cutting time for a 45-degree mitre
The design calls for a continuous diagonal line at the corner
You are prepared for tighter cut tolerances (0.2 degrees on the mitre)

05Series availability

The Model C is available for the four most common T-slot series:

Series	Profile bore	Tie rod	Typical profile
20 series	Phi6 mm	M6	20 x 20 and 20 x 40 profiles
30 series	Phi8 mm	M8	30 x 30 and 30 x 60 profiles
40 series	Phi12 mm	M14	40 x 40 and larger 40 series
45 series	Phi12 mm	M14	45 x 45 and larger 45 series

Within each series, the connector fits any profile with the standard centre bore. It does not interact with the slots, so the slot count (2, 4, 6, 8) does not matter.

06Joint strength and what it can carry

The Model C corner joint carries tension, shear and bending through the internal tie rod and the housing. The tie rod is the primary load path: it pulls the two profiles together so the joint resists opening. The housing resists shear at the corner face.

Load direction	How it is carried	Approximate capacity (40 series)
Tension (pulling apart)	tie rod in tension	approx. 8 kN
Shear (sliding apart)	housing in shear + friction	approx. 4 kN
Bending (opening the corner)	tie rod in tension	approx. 50 Nm
Torsion (twisting)	housing + set screw	approx. 15 Nm

The capacities are approximate, for a 40 series joint with the standard M14 tie rod, tightened to the recommended torque. They are for joint design only; the profile itself may fail before the joint does, depending on the span and the wall thickness.

07Failure modes to design out

What goes wrong	Why it happens	Design it out by
Corner has a visible gap	the cut length is short or the squareness is off	specify tighter cut tolerance (+/-0.2 mm); use a CNC cut saw
Tie rod strips or breaks	over-tightened or under-tightened	use a torque wrench at the specified torque (see the data sheet)
Housing rotates in the bore	no set screw, or the set screw is loose	fit the set screw; tighten after the tie rod is torqued
Joint is loose after assembly	the bore is oversize or dirty	clean the bore before assembly; check the bore diameter
Corner cracks under bending load	the joint is carrying more bending than its rated capacity	add an external gusset bracket for heavy bending; do not rely on the tie rod alone

08What to check before you order

Procurement checklist for the Model C connector

Confirm the series: 20, 30, 40 or 45. The connector is sized to the profile centre bore.
Confirm the profile bore diameter: it must match the connector housing.
Confirm the cut preparation: square cut, +/-0.5 mm on length, 0.5 degrees on squareness. For visible corners, tighten to +/-0.2 mm and 0.2 degrees.
Confirm the quantity of joints, not profiles. Each corner needs one connector.
Confirm whether set screws are included. Some models do not have them; they are recommended for any joint carrying torsion.
Confirm the finish: zinc plated is standard. Black or nickel is available for aesthetic applications.

09Terms used on this page

Miter connector: A connector that joins two profiles at an angle by cutting the ends and fitting an internal tie rod.
Model C: The 90-degree variant: both profile ends are cut square, and the external corner is a right angle.
Model P: The 45-degree variant: both profile ends are cut at 45 degrees, and the external corner is a diagonal.
Tie rod: A threaded steel rod that runs through the connector housing and pulls the two profiles together in tension.
Housing: The zinc alloy central body of the connector that sits in the corner and resists shear.
Square cut: A cut made at 90 degrees to the profile axis, producing a flat end face.

10Questions buyers ask

What is the difference between Model C and Model P?

Model C cuts both profile ends square (90 degrees) and the corner has a right-angle edge. Model P cuts both ends at 45 degrees and the corner has a diagonal edge. The C is simpler to cut; the P is more decorative.

Do I need to cut the profile ends at an angle?

No. The Model C requires a square cut (90 degrees) on both profile ends. No mitre cutting is needed. The squareness tolerance should be 0.5 degrees for structural and 0.2 degrees for visible corners.

Does it fit all profiles in the same series?

Yes, as long as the profile has the standard centre bore for that series. The connector does not interact with the slots, so the slot count does not matter.

Can I reuse the connector if I disassemble the frame?

Yes. The connector is not damaged by disassembly. The tie rod is unscrewed, the housing is slid out, and both can be reused. The profile ends must be clean and undamaged.

What is the joint strength?

For a 40 series joint with the M14 tie rod, approximately 8 kN in tension and 50 Nm in bending. The profile itself may fail before the joint does.

Is it available in black?

Yes. Zinc plated is standard; black zinc and nickel finishes are available for aesthetic applications.

What we need to quote this connector

The series (20 / 30 / 40 / 45) and the profile bore diameter.
The number of joints (one connector per corner).
The finish: zinc plated, black zinc, or nickel.
Whether set screws are needed (recommended for torsion loads).
The profile cut preparation: confirm the cut tolerance and squareness.
The annual or per-order quantity.

Send those six items and the quotation comes back with the connector price, the finish surcharge and the lead time. The connector is a stocked item; lead time is typically 1 to 2 weeks. Browse the full connecting elements and other connecting elements ranges.