Installing the HES 9600 on Hollow Metal Frames

The HES 9600 mounts to hollow metal frames using 1/4"-20 threaded holes or blind nuts (Securitron BN-250) for thin-gauge frames under 14 gauge. Hollow metal frames, manufactured by companies including Ceco Door, Steelcraft, and Republic Doors, represent the most common frame type in commercial construction for rim exit device applications. Hanchett Entry Systems (HES), an ASSA ABLOY company, designed the 9600 surface-mount electric strike to attach directly to these frames without cutting into the frame rabbet.

The installation method depends on 2 primary factors: frame gauge thickness and thread engagement depth. Frames 14 gauge (0.075") or heavier accept direct tapping for 1/4"-20 threads. Frames lighter than 14 gauge require blind nuts or through-bolts to achieve the required thread engagement for the HES 9600's 2,000 lbs static holding force.

Hollow Metal Frame Gauge Requirements

The HES 9600 requires a minimum of 3 full threads of engagement (approximately 0.150") to achieve rated holding force. Frame gauge determines the appropriate mounting method:

Frame Gauge Thickness (inches) Mounting Method Hardware Required
12 gauge 0.105" Direct tap 1/4"-20 tap, supplied screws
14 gauge 0.075" Direct tap 1/4"-20 tap, supplied screws
16 gauge 0.060" Blind nuts Securitron BN-250 (4 required)
18 gauge 0.048" Blind nuts or through-bolts Securitron BN-250 or 1/4"-20 bolts with backing plate
20 gauge 0.036" Through-bolts with backing plate 1/4"-20 bolts, steel backing plate

6-Step Installation Process for 14+ Gauge Frames

The HES 9600 installs on 14 gauge or heavier hollow metal frames in 6 steps using direct-tapped threads:

Step 1: Position the Template

The 9000-MTK metal template kit positions the HES 9600 at the correct height relative to the rim exit device latchbolt. Place the template on the frame stop with the latchbolt centerline aligned to the template's reference mark. The standard latchbolt height for Von Duprin 99, Sargent 8800, and Precision Apex 2100 rim exit devices measures 38-1/2 inches from the finished floor to latchbolt centerline.

Template Positioning

Verify actual latchbolt height before drilling. Field conditions, including floor thickness changes and non-standard device mounting, cause variations from the nominal 38-1/2" specification. Measure from finished floor to the center of the installed latchbolt.

Step 2: Mark and Center-Punch Hole Locations

Mark 4 mounting hole locations through the template using a permanent marker or scribe. Center-punch each mark to prevent drill bit walking on the hardened steel frame surface. The HES 9600 uses a rectangular mounting pattern with holes positioned at:

Step 3: Drill Pilot Holes

Drill #7 (0.201") pilot holes at each marked location using a cobalt or titanium-coated bit rated for hardened steel. Hollow metal frames contain 18-8 stainless steel or galvanized cold-rolled steel with Rockwell hardness ratings between B60 and B85. Use cutting oil and maintain moderate drill speed (400-600 RPM) to prevent work hardening.

Step 4: Tap Threads

Tap 1/4"-20 UNC threads in each pilot hole using a spiral-point tap. Apply tapping fluid and maintain perpendicular alignment to the frame surface. For 14 gauge frames (0.075"), the tap engages approximately 4 full threads—sufficient for rated load capacity. Clean metal chips from the tapped holes using compressed air or a vacuum.

Thread Engagement Warning

Frames lighter than 14 gauge provide insufficient thread engagement for direct tapping. The 1/4"-20 threads strip under load, causing strike failure. Use blind nuts (Securitron BN-250) for 16 gauge and lighter frames.

Step 5: Configure Voltage and Operation Mode

Before mounting, configure the HES 9600 for the correct voltage and operation mode. The strike ships configured for fail-secure operation at 24V DC. Adjust settings as required:

Voltage Selection Connect appropriate pigtail: red/black for 24V DC, orange/brown for 12V DC
Fail-Secure (default) Locked when power is off, unlocks when energized
Fail-Safe Unlocked when power is off, locks when energized (voids windstorm rating)

See the HES 9600 wiring diagram for complete electrical connection details.

Step 6: Mount Strike and Install Cover

Secure the HES 9600 base plate to the frame using the 4 supplied 1/4"-20 x 3/8" screws. Tighten in a cross pattern to 25-30 in-lbs torque. Verify the keeper pocket aligns with the rim exit device latchbolt path. Install the decorative cover by sliding it over the base and pressing until the retention clips engage.

Blind Nut Installation for Thin-Gauge Frames

Frames 16 gauge (0.060") and lighter require Securitron BN-250 blind nuts to provide adequate thread engagement. Blind nuts install from the accessible (strike) side of the frame and expand behind the frame material when tightened.

Blind Nut Installation Process

Install blind nuts in 4 steps:

  1. Drill clearance holes: Use a 25/64" (0.391") drill bit to create clearance holes at each mounting location
  2. Insert blind nut: Thread the BN-250 onto the installation mandrel and insert through the clearance hole from the strike side
  3. Expand the nut: Turn the mandrel clockwise until the blind nut collapses and grips the backside of the frame material
  4. Remove mandrel: Unthread the mandrel counterclockwise, leaving the blind nut permanently installed
Blind Nut Part Number Securitron BN-250
Thread Size 1/4"-20 UNC
Grip Range 0.030" to 0.150" material thickness
Quantity Required 4 per HES 9600 installation
Installation Tool BN-250 includes mandrel; alternative: Marson M39302 rivet nut tool

Frame Preparation Considerations

Frame Stop Configuration

The HES 9600 surface-mounts to the frame stop (the portion of the frame against which the door closes). Verify the frame stop width accommodates the strike's 1-3/4" width. Standard hollow metal frames provide frame stop widths of 2" or greater, sufficient for HES 9600 installation without modification.

Wiring Access

Route strike wiring through the hollow frame cavity. Drill a 1/2" wire access hole behind the strike mounting location if no existing knockout or cable entry point exists. Position the hole where the HES 9600 base plate conceals it after installation. The HES 9600 accepts wiring from the top, bottom, or back of the strike body.

Frame Reinforcement

Standard hollow metal frames rated for rim exit devices include internal reinforcement at the strike zone. This reinforcement, typically 14 gauge steel welded inside the frame, provides the material thickness required for direct tapping. Verify reinforcement exists before drilling—unreinforced sections collapse under drill pressure and provide inadequate mounting strength.

Reinforcement Verification

Tap the frame stop at the strike location with a screwdriver handle. Reinforced areas produce a solid sound; unreinforced hollow sections sound distinctly different. Alternatively, measure material thickness with a sheet metal gauge through an existing hole or knockout.

Windstorm-Rated Installation Requirements

Installations requiring Florida Building Code FL# 14307 windstorm certification must meet 3 additional conditions:

The HES 9600 carries ANSI/SDI A250.13 windstorm certification and Florida Building Code approval for hurricane zone installations in High-Velocity Hurricane Zones (HVHZ) including Miami-Dade County. See the HES 9600 Florida Building Code compliance guide and HES 9600 Miami-Dade NOA requirements for jurisdiction-specific requirements.

Troubleshooting Hollow Metal Frame Installations

Stripped Threads

Threads strip when frame gauge provides insufficient engagement depth or when screws are overtightened. Solutions include:

  1. Install Securitron BN-250 blind nuts in the damaged holes
  2. Use HeliCoil thread inserts to restore 1/4"-20 threads
  3. Relocate the strike using offset mounting holes (verify latchbolt alignment)

Strike Misalignment

Misalignment between the HES 9600 keeper and rim exit device latchbolt causes binding or failure to latch. The HES 9600 includes ±1/16" vertical adjustment in the keeper. For larger misalignments, the slotted mounting holes allow repositioning the entire strike body.

Excessive Door Gap

The HES 9600 accommodates door-to-frame gaps of 1/8" to 3/16". Gaps exceeding 3/16" prevent the Pullman latchbolt from fully engaging the keeper pocket. Address excessive gaps by adjusting door hinges, adding weatherstripping, or installing the optional HES filler plate (ordered separately).

For additional troubleshooting guidance, see the HES 9600 troubleshooting guide.

Tools and Materials Required

Item Specification Purpose
Drill Variable speed, 1/2" chuck Pilot hole drilling
Pilot Drill Bit #7 (0.201") cobalt or titanium Pre-drill for tapping
Tap 1/4"-20 UNC spiral point Create mounting threads
Tap Handle T-handle or adjustable Manual tapping
Center Punch Spring-loaded or manual Mark hole locations
Screwdriver #2 Phillips Mount strike, install cover
Torque Screwdriver 25-30 in-lbs range Final screw tightening
Cutting Oil Tapping fluid Lubricate drill and tap
Template Kit HES 9000-MTK Position strike accurately
Blind Nuts (if needed) Securitron BN-250 (qty 4) Thin-gauge frame mounting

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