Key Specifications of Waterson ⅝ Radius Hinges - Standard Screw Pattern Include:
- Door Height: Up to 6 ft (2 pcs) / 7 ft (3 pcs) / 8 ft (4 pcs)
- Door Weight: Up to 150 lbs (2 pcs) / 260 lbs (3 pcs) / 330 lbs (4 pcs)
- Gate Thickness: 1 ⅜” to 2 ¼”
- Material: Stainless Steel SS304 - SS316 available on selected models
- Finish: Satin Stainless Steel (US32D), Flat Black (US19), Satin Brass (US4), Dark Satin Bronze (695). Custom finishes available
- Type: Mechanical Self-Closing (A-C) or Hydraulic Soft-Closing (B-D)
- Features: Fire Rated (A-B Models), Hold Open (C-D Models)
- Application: Interior and exterior doors with ⅝″ radius corner preparation using standard screw patterns, including commercial and residential door openings.
What Is a 5/8 Radius Hinge
A 5/8 radius hinge has rounded corners with a curve equal to the edge of a US quarter. It’s the preferred cut for commercial and factory-prepped doors. The rounded shape seats cleanly without extra chiseling, saving time during installation and ensuring a tight, professional fit.
Waterson’s version takes this same form factor and adds controlled closing power — ideal when you want both appearance and performance in one component.
Why Choose Waterson 5/8 Radius Hinges
- Integrated heavy duty door closer: Adjustable tension for controlled self-closing.
- Load capacity: Handles doors up to 260–330 lbs with consistent swing.
- Stainless steel: 304/316-grade for corrosion and weather resistance.
- Certified durability: UL 3-hour fire rating and ANSI/BHMA A156.17 (1 million cycles).
- Field adjustability: Speed and tension tuning without removing the hinge.
Each hinge is engineered to handle frequent use and tough environments — the kind where standard hardware wears down fast.
How to Measure Hinge Radius
- Use a quarter: If the corner curve matches the coin, it’s 5/8 radius.
- Check both mortises: The door and frame must share the same radius.
- Don’t mix radii: Combining different corners causes misalignment and poor seating.
A 5/8 radius door hinge will fit most commercial door preps without modification. When your opening needs a closer that’s built in — not bolted on — specify Waterson’s extra heavy duty door closer with 5/8 radius prep.
1/4 vs 5/8 Radius Hinges
1/4-inch radius hinges feature a subtle, tighter curve suited for a modern, precise look, while 5/8-inch radius hinges have a wider, more pronounced curve often found on traditional or pre-hung doors.
- Appearance: 1/4" offers a squarer, premium look; 5/8" offers a softer, more rounded, traditional look.
- Measurement: To determine which you have, place a coin in the hinge corner. A dime matches a 1/4" radius, while a quarter matches a 5/8" radius.
- Application: 5/8" is common in older or standard residential homes; 1/4" is often used in newer or specific, specialized applications.
- Installation: 5/8" allows for easier, slightly faster, rounded, or, machine-cut mortises.
Therefore, when replacing, it is best to measure the existing hinge to avoid having to re-chisel the door frame.
Common 5/8" Radius Hinge Sizes
3.5" × 3.5" (3-1/2")
The most standard size for interior residential doors (bedroom, bathroom, closet).
Note: Waterson Hinges does not supply this hinge template.
4" × 4" (4")
Commonly used for heavier interior doors or standard exterior doors.
Waterson Hinges does supply this hinge template.
Common Applications
- Fire-rated corridor doors
- Office and classroom doors
- Hotel and apartment entries
- Stairwell and garage access doors
- Public building and mixed-use entrances
- Black 5/8 radius hinge
- Silver 5/8 radius hinge