Damper Stays Hardware Basics

Damper Stays Hardware Basics

On this page, learn the basics about how damper stays work, explore the different types available, and discover how to effectively utilize them.
Use our selection tool for damper hinges and damper stays to choose a product that meets your needs.

What is a damper stay?

A damper stay is a stay that allows doors and lids to open or close slowly. The slow opening function is called "Soft Open", and the slow closing function is called "Soft Close" or "Soft Down".
By regulating the speed of opening and closing, damper stays not only reduces noise and impact but also adds a sense of luxury to the furniture or equipment. Additionally, it enhances safety by reducing the risk of finger pinching.

Damper stays are also referred to as “soft down stays”!

How Does the Damper Stay Soft-Close and Soft-Open Functionality Work?

Many of our damper stays feature a unique structure called "Lapcon", which utilizes a viscous fluid.
They are also referred to as "Lapcon Stays". The soft-close and soft-open functions use the resistance of the viscous fluid to operate.

Orifice Damper

Resistance is created when the viscous fluid passes from a larger diameter cylinder to a smaller diameter cylinder.

Rotary Damper

Resistance is created by a damper using rotating disks, which are filled with a viscous fluid.

Types of Damper Stays

Flap Opening Direction

Downward Opening
(Flap Down)
Upward Opening
(Flap Up)
Top Opening
Downward Opening
Swing Lift-up Opening
Swing Lift-down Opening
Swing Upward Opening
Upward Folding Opening
Over the Top Flipper Opening
Downward opening flaps are often used for doors that are lower than eye level, such as TV cabinets. Upward opening flaps are used for doors that are higher than eye level, such as kitchen cabinets. Top opening flaps are often used for bench storage and toy box lids.

Types of Damper Stays

General Type

This type is installed to the side board and the door.

Easy Installation Type

Simply install by aligning the stay with the edge of the side board and fix in place with screws.

Hinge Integrated

Integrated design combines a concealed hinge and lid stay. By mounting the lid stay over a concealed hinge, the parts that are normally separated into two places are consolidated into one.

For Counter Flaps

This damper stay is recommended for counter flaps. Damper function works even if the flap is only opened slightly and allows for soft-close movement.

Multifunctional Type

A multifunctional damper stay that not only provides soft-close function, but also features a lift-assist function allowing for light opening of doors and a free-stop function to hold the door at any desired position.

How to Choose a Damper Stay

Sometimes doors and flaps still slam even after damper stays have been installed. This can happen if the wrong damper stay for the weight and size of the door is chosen. Choosing the correct product is crucial for achieving soft-close movement.
For instance, if the door is large and heavy, but the resistance of the stay is weak, the door may still slam shut. Likewise, if the door is small and light, but the resistance of the stay is strong, the door might stop midway.
Knowing the door moment is the key factor in selecting the right damper stay.

What Is the Door / Lid Moment?

The moment of a door or lid refers to the force required to rotate it along an axis. The moment varies depending on the opening angles of the door, as shown in the diagram on the right. When selecting a damper stay, it's crucial to choose one that matches the "maximum moment" of the door or lid.
For downward opening doors
① When at a 10-degree angle, the rotation force on the door is weak.

② When at an 80-degree angle, the rotation force on the door is strong.

If you choose a damper stay based on a similar small angle as shown on the left (meaning based on weak force),

the damper stay would fail to withstand the increase in door moment and slam open. By selecting the damper stay based on the maximum moment within the door's opening angle (at an angle similar to the image on the left), the door will open slowly at any angle.

The formula for calculating the maximum moment is as follows.

Max. Moment of Door/Lid (N·m)   = Weight of Door / Lid (kg) × 9.80665 × Max. Horizontal Distance from the Rotational Center to the Center of Gravity (m)

①Side Board
②Rotational Center (where the hinge is attached)
③Horizontal Distance from Rotational Center to Center of Gravity
⑤Center of Gravity

The center of gravity of the door is at the geometric center of the shape for a door made of a single piece of uniform material.

Click here for more details about the center of gravity and how to calculate it for an L-shaped door.

Easily Calculate Door Moment with Our Selection Tool!

Select the flap/door movement and input the door weight, the distance to the center of gravity, etc., and the appropriate damper stay will be automatically selected.

Damper Stays with Adjustable Damper Force

Some products, such as the NSDX Soft-Down Series and the CSD-10-TV, allow for adjustment of the damper force after installation. Not only can the closing and opening speed of the door be adjusted, but they can also be used with doors of various sizes and weights compared to other stays.

See all damper stays with adjustable damper force

Related Products for Soft Close of Swing Doors

Although the damper stay is not compatible with swing doors, Damper Catch can be used instead to slowly close the door.
The damper begins to work when the arm part of the body comes into contact with the door seat, causing it to close slowly.
Although the damper stay is not compatible with swing doors, you can use a product called damper catch to slowly close the door.
The damper begins to work when the arm part of the body comes into contact with the door seat, causing it to close slowly.
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