TriMark Corporation - Door Hardware Design and Hardware Considerations

Consider the access hardware early in the design process:

We sincerely hope that you are considering TriMark hardware solutions early in your design process. We strongly feel that leaving access hardware decisions until the end of a project causes compromises, potential problems and higher costs. The purpose of this section is to give you some guidelines and assistance for the proper selection of our products or you can give us a call. TriMark welcomes the opportunity to provide design application assistance. Here are a few benefits for early involvement:

The more we can understand your application, the greater the chances that we can provide a latching solution that best fits your needs. It may even lead to a standard product and a lower cost.
An assurance that we will meet your timetables, product specifications and cost targets.
TriMark will also provide production samples and prototypes and can also assist in door mock-ups and testing to demonstrate our solutions in your application.

Strength/Duty Considerations:

The door weight, striker bolt load and the expected cycle life are 3 factors that need to be considered in the hardware specification. Each of these considerations is detailed below. In addition, most of TriMark latches have a performance graph that reveals the relative performance for the correlation of door cycles and striker bolt loads.

Door weight

How much does the door weigh? Put a sample of the door on a scale, calculate the weight using the bill of materials and add-up the component weights or calculate the door weight by multiplying the door length X width X height X average density. The following are categories of door weights used by TriMark:

Duty	Door Weight
Light weight	Less than 50 lbs. (<23 kg)
Medium weight	50 to 100 lbs. (23-45 kg)
Heavy weight	100 to 200 lbs. (45-91 kg)
Extra-heavy weight	More than 200 lbs. (>91 kg)

Striker Bolt Loads
What is the striker bolt load (SBL) that is put on the latch by the gaskets/seals, strike adjustment, door camber, etc. when the latch is fully engaged or the door closing force (DCF), the force required to shut a door completely. This number should be a range (min/max.) with consideration for variability. This value can be obtained by measuring the force required to push the door into the fully latched position (DCF) with a force gauge or measuring the striker bolt load (SBL) using a load cell. Measuring the door circumference and multiplying by the compression force of the door seals can also calculate this value. Specific procedures for measuring SBL and DCF can be found under "Information about loads on Rotary Door Latching Hardware". The following are categories of door closing force (DCF) used by TriMark: (Note: These values are also called Door Seal Pressures in TriMark Technical Publications)

Duty	Door Seal Pressure
Light	15 to 25 lbs. (7-11 kg)
Medium	25 to 50 lbs. (11-23 kg)
Heavy	50 to 150 lbs. (23-68 kg)
Extreme	More than 150 lbs. (>68 kg)

The following chart includes categories of Striker bolt loads (SBL) and is the preferred method of specifying rotary door latching hardware:

Duty	Striker Bolt Loads
Light	0 to 15 lbs. (0-7 kg)
Medium	15 to 25 lbs. (7-11 kg)
Heavy	25 to 75 lbs. (11-34 kg)
Extreme	More than 75 lbs. (>34 kg)

Expected number of door cycles (life)

What is the expected life of the door hardware system in operational cycles before replacement or maintenance is required? Please consider the average operations per day times the average days per year of operation times the expected life in years. For example: 20 cycles per day X 250 days per year X 10 years = 50,000 cycles. The following are categories of usage used by TriMark:

Usage	Door Cycles
Low usage	Less than 25,000 cycles
Medium usage	25,000 to 100,000 cycles
High usage	100,000 to 250,000 cycles
Extreme usage cycles	More than 250,000

Other Considerations:

Door details

What are the door thickness (space available inside the door to mount), door structure, materials and other constraints that need to be considered? Is there a CAD file available of the door design?

Environment

What is the environment that the hardware needs to operate within? Some elements to consider include:

Vibration
Corrosion resistance (salt/chemicals/etc.)
Water and dust exposure
Temperature extremes [e.g. 120° F (49°C) to -60° F (-51°C)]
UV exposure

Operational effort

What are the operational effort guidelines or limitations that your application has? Will your product need to be operated by an elderly person or a small child?

Forced entry requirement

Are there any forced entry or security requirements for your product?

Aesthetics

Are there any specific requirements that the hardware must comply with? Will the hardware be mounted flush or can surface mounting be acceptable? Does styling and relative size need to be considered?

Materials

Are there any specific materials or finishes that the hardware must be constructed from? For example: steel, die cast zinc, plastic, powder metal, etc.

Industry or governmental specifications or guidelines

Does the hardware have to comply with FMVSS 206, FMVSS 302 or other governmental, industry or applicable specifications or regulations?

Product types

Is there any specific product type that this application requires? TriMark has a list of product types with features and benefits of each to assist you in the selecting the appropriate product. Click here to search for the product that's appropriate for your application.

Installation requirements

When designing the door hardware into the door, consideration needs to be made as to the installation process and any special requirements, such as:

Manufacturing tolerances
Installation method
When will the hardware be installed and by whom?
When will the door be installed and by whom?
Are there any adjustability requirements?
Mounting torque recommendations?

Costs

The initial purchased cost is just one factor to consider when making a hardware selection. At TriMark, we try to assist our customers in recognizing the total life cycle costs of the hardware including installation and warranty costs, cost of quality and cost to maintain the hardware. Some other cost considerations include:

Service intervals
Can lubrication be added at regular intervals?
Serviceability

System

The entire door hardware system must be included in the design process: latch, handle, rods/linkages, fasteners, hinges, etc. This ensures compatibility of all components within the hardware system. If
FMVSS 206 is a requirement, then all of the components must comply with strength and inertia requirements.

Compatibility of products

TriMark has assigned a duty rating for all of its latches and handles and has cross-referenced those products that are compatible with each other through a "Used With" classification. In addition, there are application-related drawings that show products in a system environment. These drawings can also be located through an Industry/System search.

The following are guidelines for the application of products for the respective duty ratings:

	Light Duty	Medium Duty	Heavy Duty
Door Weights	Less than 50 lbs. (<23 kg)	50 to 100 lbs. (23-45 kg)	100 to 200 lbs.(45-91 kg)
Striker Bolt Loads	0 to 15 lbs. (0-7 kg)	15 to 25 lbs. (7-11 kg)	25 to 75 lbs. (11-34 kg)

Additional

All products listed in our online catalog are representative of products that TriMark manufactures. If a standard TriMark product does not fit your application requirements, ask about an extension or modification or TriMark can develop an all-new design that is engineered specifically for your application. You can submit your product idea suggestion online through our Product Idea Suggestion Form.