Norton Rixson HM51 Series 3/4″ Offset Shallow Depth Floor Closer for Hollow Metal Doors – 250 lbs Capacity with BackcheckProfessional Shallow-Depth Floor Closer for Hollow Metal Door ApplicationsThe Norton Rixson HM51 Series delivers professional-grade door control for hollow metal doors weighing up to 250 lbs. This 3/4″ offset-hung floor closer features shallow-depth design ideal for multi-story buildings, with robust Cycolac rust-proof cement case construction. The system includes three special steel 4-1/2″ ball bearing standard weight hinges with 3/4″ offset for complete door support and control. Single acting operation with separate independent valves provides precise control over closing speed, latch speed, and backcheck functions.Professional Features & BenefitsHeavy-Duty Door Support: Supports doors up to 250 lbs with door widths up to 4′ 0″ (1219mm) for versatile commercial applications.Shallow Depth Design: 3/4″ offset-hung configuration with shallow depth construction ideal for upper levels of multi-story buildings where space is limited.Complete Hinge System: Includes three special steel 4-1/2″ ball bearing standard weight hinges with 3/4″ offset for doors over 90″ in height.Precision Control Valves: Separate independent valves for closing speed, latch speed, and backcheck provide enhanced operational control and adjustment capability.Vandal-Resistant Construction: Concealed in-floor installation with Cycolac rust-proof cement case provides protection from tampering and weather exposure.Flexible Installation Options: Available with floor plate or threshold installation, plus interchangeable spindle adapters and extended spindles in 1/2″ increments up to 2″ longer than standard.Hold Open Configuration: Available non-hold open (NBC) or automatic hold open (ABC) with 90 or 105 options, doors swing 5 beyond hold open point.Manufacturer Warranty: 2-year limited warranty for added confidence and protection.Technical SpecificationsCommercial/Residential: CommercialCover Type: Cycolac, rust-proof cement caseDelay Function: YesDepartment: Door HardwareDoor Swing: Single ActingDoor Weight: 250 lbs.Duty Level: Standard DutyFire Rating: YesHang Type: Offset HungHold Open Feature: NoMounting Method: OffsetProduct Category: Door ControlsProduct Group: Door ControlsProduct Model: HM5103NBCProduct Subgroup: Door Closers – FloorProduct Type: Floor Door Closers – Shallow DepthSeries: HM51 SeriesSpring Type: Fixed SizeSubcategory: Floor ClosersUL Listing Type: Certain models UL Listed (F prefix)Warranty: 2 Year LimitedInstallation & OperationReview manufacturer specifications and verify door preparation requirements including door thickness, weight capacity up to 250 lbs, and hollow metal door and frame compatibility.Use manufacturer-provided templates to mark mounting hole locations accurately for floor installation and hinge mounting positions.Prepare floor surface and door frame by drilling required holes and routing as specified for the 3/4″ offset configuration and shallow depth requirements.Install the three included special steel 4-1/2″ ball bearing hinges with 3/4″ offset, adding additional hinge for doors over 90″ in height as warranted.Mount floor closer unit with surface mounted bottom arm using thru bolts, ensuring proper alignment with door swing path and selected hold open configuration (90 or 105 if applicable).Adjust the separate independent valves for closing speed, latch speed, and backcheck to achieve desired door operation and test throughout full range of motion. Refer to manufacturer documentation for complete installation details and valve adjustment procedures.Professional ApplicationsCommercial Office BuildingsEducational FacilitiesHealthcare InstitutionsMulti-Story Building Upper LevelsIndustrial and Warehouse FacilitiesGovernment and Municipal BuildingsRetail Establishments with Heavy TrafficWhy Choose Norton Rixson Quality?Norton Rixson HM51 Series floor closers deliver professional-grade reliability with robust steel construction and Cycolac rust-proof cement case designed for demanding commercial applications. The shallow-depth design with 250 lb door weight capacity and comprehensive valve control system ensures dependable performance in multi-story buildings where space constraints and heavy-duty operation are critical. 2-year limited warranty provides added confidence for long-term commercial installations.