T hinges are measured primarily by the length of the strap (the top of the “T”), along with several secondary dimensions that affect strength, fit, and alignment. Correct measurement ensures the hinge can support the door or gate without sagging.

1. Strap Length (Primary Measurement)

• Main size of a T hinge

• Measured from the end of the strap to the center of the hinge pin

• Often listed as the hinge size

Examples

• 200 mm T hinge → strap is 200 mm long

• 8-inch T hinge → strap is 8 inches long

Why it matters:

• Longer straps spread weight over a larger area

• Essential for heavy doors and gates

2. Strap Width

• Measured across the strap, perpendicular to its length

• Affects:

• Load distribution

• Screw or bolt spacing

• Resistance to twisting

Wider straps provide better support for heavier or wider doors.

3. Hinge Leaf Length (Vertical Leg of the “T”)

• Measured top to bottom of the vertical plate

• Determines how securely the hinge mounts to the frame or post

This measurement is especially important for:

• Gates

• Barn doors

• Exterior applications

4. Pin Diameter

• Measured across the hinge pin

• Larger pin diameter = higher load capacity and durability

Critical for:

• Heavy wooden doors

• Metal gates

• Outdoor installations exposed to wind

5. Overall Height (Installed Height)

• Distance from the top of the vertical leaf to the bottom when installed

• Helps verify clearance and alignment on posts or frames

6. Load or Weight Rating

T hinges are also specified by maximum supported weight.

To size correctly:

• Estimate the total door or gate weight

• Divide by the number of hinges

• Choose hinges with a safety margin

Never select hinges at their absolute maximum rating.

Typical T Hinge Size Reference

Always adjust based on weight and width, not just height.

Common Measurement Mistakes

• Measuring total hinge length instead of strap length to pin center

• Ignoring weight rating

• Choosing short straps for wide or heavy doors

• Overlooking pin diameter for outdoor use

Summary

T hinges are measured mainly by strap length, with strap width, vertical leaf length, pin diameter, and load rating also playing key roles. The strap length determines how well the hinge supports the door or gate and prevents sagging over time.