Skip to content
heavy duty garage door hinges

4pcs Self Closing Interior Door Hinges | Mechanical | Fire Rated | 4x4 | 8ft | 330 lbs | 1 ⅜ or 1 ¾” Thick | SS304 | K51M-400-A4

$532.80 - $608.80
$532.80
$532.80 - $608.80
$532.80

Looking for self closing interior door hinges that deliver controlled closing force and speed without overhead closers?

By using a mechanical hinge setup that fits 4x4 full-mortise doors up to 330 lbs, Waterson hinge set lets you dial in tension at the hinge ends and maintain cycle performance for interior hotel, corridor, and 8ft door applications. 10 years warranty

Warning : Special finish (US4) is non-refundable

  • DESCRIPTION
  • DETAILS
  • SPECIFICATIONS
  • VIDEO

  • Applications

    • Hotel Rooms 
    • 3Hr Fire-rated
    • Interior & Exterior  
    • Arch Top 
    • Heavy Duty
    • Courtyard Style
    • 8ft Door

    Product Description and Features

    • Fully adjustable closing force and speed according to environment needs
    • Numerical adjustment panel on hinge end to set up precise tension
    • Mechanical only mechanism supporting heavy duty and fully exterior  
    • Aesthetically pleasing compared to door closers -- without extrusive arms 
    • UL certified cycle testing ensures many years of low maintenance.

  • Installation Kits  

    • Both machined #12-24 UNC ½”L and wooden tapping #12 x 1 ¼” screws included -- eight (8) of each type per hinge. Pack contains five (5) spares as well.
    • Three steel adhesive shims for gap adjustment between door and frame as needed
    • Tension Crook: Keeps hinge open during installation  
    • 5mm & 3mm hex allen wrenches  

    Compliance Standards

    • ANSI A156.17 Grade 1 : one million cycle testing  
    • ANSI A156.7 Template Hinge : 4” x 4”
    • CSI Spec 08 7100 Door Hardware & 08 7808 Self-closing Hinges  
    • ADA Force : opening force no more than 5 lbs
    • ADA Closing Speed: at least 5 sec to move from m 90° to 12°
    • ADA Vertical Clearance: Does not intrude into the doorway as do some overhead closers

  • Specifications

    Product SKU K51M-400-A4
    Hinge Type Full Mortise, 4 Inch x 4 Inch
    Hinge Material Stainless Steel
    Door Weight From 40lbs to 330lbs 
    Approx Door Size 1150mm W x 2200mm H (4ft x 8ft)
    Door Thickness 1 ¾” (40-50 mm)
    Self-closing o
    Fluid Motion x
    Hold-open x
    Fixing Method Screw-On, only spot weld AFTER speed adjustment
    Color/Finish Satin Brushed,Black,Gold,ORB
    Combination/Quantity DS.SA.SA.SA1,4 Pack





  • Product Video

Color: Satin Stainless Steel-US32D

FAQ

Do I need to prepare anything before installing Waterson hinges?

Waterson hinges are built for hassle-free installation, but we still suggest reading through our installation guide beforehand. You can find it on our Installation page.

How can I adjust the tension?

Our hinges feature a clearly marked tension panel for quick and simple adjustments. For full guidance, please refer to the Adjustment page.

What’s included in the warranty?

The warranty covers any material or manufacturing defects. It doesn’t apply to issues caused by shipping, impact, improper storage, or misuse. For full terms, visit our Warranty page.

How do I get a quote for bulk orders?

Just leave your request on our Request Quotation page, and our team will reach out within 12 hours. Need help right away? Give us a call.

Where are products shipped from?

Most of our orders ship from warehouses in Michigan and California.
For urgent or high-volume orders, we may also ship directly from our Taiwan headquarters. FedEx or UPS handles most deliveries (1–5 business days), while large-volume orders go by ocean freight (30–60 days).

What’s the delivery time?

Once your payment is confirmed, shipping usually takes 3–5 business days, depending on your region.

How is the shipping fee calculated?

Shipping costs depend on domestic courier rates and the weight of your package. Since we ship within the U.S., charges are typically standard.

How do I track my shipment?

We’ll send a confirmation email with a tracking number after your order ships. You can use this number to follow the delivery progress.