SDC Uniflex Series 55-B Heavy ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$591.00
$416.70
SDC Uniflex Series 55-B Heavy Duty 3/4" Mortise Electric Strike with Field Reversible Fail-Safe/Fail-Secure Operation

SDC Uniflex Series 55-B Heavy Duty 3/4" Mortise Electric Strike with Field Reversible Fail-Safe/Fail-Secure Operation

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Model: 55-BQ
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$591.00
$416.70
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SDC Uniflex Series 55-B Heavy Duty 3/4"; Mortise Electric Strike with Field Reversible Fail-Safe/Fail-Secure Operation

Professional Access Control Solution for High-Security Applications

The SDC Uniflex Series 55-B electric strike delivers heavy-duty performance for access control of cylindrical locksets, mortise locksets with or without deadbolts, and mortise exit devices. Designed for installation in hollow metal frames, this 3/4"; latchbolt electric strike accepts up to 1"; throw deadbolts and features field selectable dual voltage operation at 12/24 VDC. The stainless steel construction and heavy cast housing provide exceptional durability rated for 1,000,000 endurance cycles with 2500 holding force and 70 ft-lbs dynamic strength.

Professional Features & Benefits

  • Heavy-Duty Durability: Tested to 1,000,000 endurance cycles with 2500 holding force and 70 ft-lbs dynamic strength for long-term reliability in high-traffic applications.
  • Flexible Power Options: Field selectable dual voltage operation at 12/24 VDC with voltage and current spike protection for various system requirements.
  • Fail-Safe/Fail-Secure Operation: Field selectable operation allows adaptation to specific security requirements with internally mounted solenoid design.
  • Heavy-Duty Construction: Stainless steel components with heavy cast housing body and keeper provide exceptional durability and corrosion resistance for commercial applications.
  • Universal Compatibility: Accepts 3/4"; throw latchbolts and up to 1"; throw deadbolts for versatile installation with cylindrical locksets, mortise locksets, and mortise exit devices.
  • Retrofit-Friendly Design: Retrofits existing ANSI 4-7/8"; strike prep with no centerline relocation required, featuring interchangeable faceplate design for new or retrofit applications.
  • Professional Certifications: UL 1034 Burglary-Resistant Electric Locking Mechanisms, UL 10C Positive Pressure Fire Tests, and ANSI/BHMA A156.31 Grade 1 certified for code compliance.
  • Tamper-Resistant Design: Corrosion and tamper resistant construction with horizontal alignment adjustment and non-handed operation for enhanced security.

Technical Specifications

  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Door Type: Hollow Metal
  • Dynamic Strength: 70 ft-lbs
  • Electronic: Yes
  • Endurance Cycles: 1,000,000
  • Holding Force: 2500
  • Latch Throw: 3/4";
  • Product Category: Electronic Access Controls
  • Product Group: Electronic Access Controls
  • Product Model: 55-B
  • Product Subgroup: Electric Strikes
  • Product Type: Electric Strikes
  • Product Voltage: 12/24 VDC
  • Series: 55 Series
  • Subcategory: Electric Strikes
  • Switch Device: SPDT

Professional Applications

  • Commercial Building Security Systems
  • Educational Institution Access Control
  • Healthcare Facility Security
  • Government and Municipal Buildings
  • Industrial Facility Access Points
  • Multi-Tenant Residential Properties
  • Retail Loss Prevention Systems

Why Choose SDC Quality?

SDC electric strike products deliver professional-grade reliability with stainless steel construction and heavy cast housing rated for 1,000,000 endurance cycles. UL 1034, UL 10C, and ANSI/BHMA A156.31 Grade 1 certifications ensure code compliance and performance standards. Engineered for demanding commercial applications where dependable access control performance is essential.

Manufacturer Resources

SDC Full Catalog

Product Specs

Subcategory:
Electric Strikes
Series:
55 Series
Dynamic Strength:
70 ft-lbs
Endurance Cycles:
1,000,000
Product Group:
Electronic Access Controls
Product Subgroup:
Electric Strikes
Product Type:
Electric Strikes
Latch Throw:
3/4"
Commercial/Residential:
Commercial
Electronic:
Yes
Door Type:
Hollow Metal
Holding Force:
2,500 lbs
Product Model:
55-B
Product Voltage:
12/24VDC
Switch Device:
SPDT
Product Category:
Electronic Access Controls
Department:
Door Hardware

SDC 55-BQ – Frequently Asked Questions

1) Will the SDC 55-B electric strike drop into an existing ANSI strike prep without cutting the frame?
Yes. The Uniflex 55-B retrofits an existing ANSI 4-7/8 inch strike prep with no centerline relocation, and the faceplate is interchangeable so the same body covers new work or a retrofit. It is built for hollow metal frames, so if your opening is an aluminum jamb this is the wrong strike for it.
2) What latchbolt and deadbolt throw will the SDC 55-B electric strike accept?
The 55-B takes a 3/4 inch throw latchbolt and will accept deadbolts up to 1 inch throw. That is what lets it work with cylindrical locksets, mortise locksets with or without a deadbolt, and mortise exit devices. If the lock on your door throws a 5/8 inch latch only, you are in a lighter class of strike and a 5/8 inch unit like the Hager 2925 is the closer match.
3) Can the SDC 55-B be set to unlock on a fire alarm or power loss?
Both modes are field selectable on the 55-B, so one part number covers either. Set it fail-safe and the keeper releases when power drops, which is what you want on a stair or egress door tied to the fire alarm. Set it fail-secure and the door stays locked through a power loss, which is the usual choice on an exterior or tenant entry. The solenoid is internally mounted and the strike is non-handed, so you are not reordering for a left or right hand opening.
4) Does the SDC 55-B work on a fire rated door?
The Uniflex 55-B is listed to UL 10C Positive Pressure Fire Tests and to UL 1034 for burglary-resistant electric locking mechanisms, and it is ANSI/BHMA A156.31 Grade 1. That is the certification package a facility or institutional spec usually calls for on a labeled opening. Note that a fail-safe setting releases the latch on power loss, so on a labeled door the fail-secure setting is normally the one that belongs there.
5) What is the difference between the LBM and LBMLCM options on the SDC 55-B electric strike?
Those are the monitoring choices, and they are what you specify on the order. LBM gives latch status only, telling the panel whether the lockset latchbolt is projected into the keeper. LBMLCM adds keeper deadlock status on top of it, so you know both that the latch is in and that the keeper is locked, which is what an access control integrator wants for a genuine secure-door report. Ordering with no device option gets you a plain strike with no monitoring. The switching is SPDT.
6) Can the SDC 55-B be used in an aluminum storefront jamb, or do I need a different strike?
The SDC 55-B is built for hollow metal frames. For aluminum jambs, the Adams Rite 7100 Series and the Adams Rite 7160 are electric strikes made for aluminum jambs with a 1-1/4 inch by 4-7/8 inch faceplate. The Adams Rite 7170 is the same faceplate size but is intended for hollow metal and wood jambs. None of the three Adams Rite strikes carry a fire rating, so an aluminum opening that also needs a fire label calls for a different selection.
7) What is the closest equivalent to the SDC 55-B if I need an electric strike for mortise and cylindrical locks in a hollow metal frame?
The SDC 55-B is a Grade 1 mortise electric strike for hollow metal frames with field selectable fail-safe/fail-secure operation at 12/24 VDC and a 3/4 inch latch throw. The Von Duprin 6400 32D is a Grade 1 heavy duty modular electric strike for mortise or cylindrical locks in satin stainless steel, fail-secure, with a 3-hour UL 10C fire rating in the fail-secure configuration. The Hager 2930 is a fire rated Grade 1 electric strike for cylindrical and mortise locks with 12/24 VDC dual voltage and field reversible fail safe/secure operation, which is the closer match if field reversibility and dual voltage are both required.
8) I need latchbolt monitoring on an electric strike. What are my options besides the SDC 55-B LBM?
The SDC 55-B is ordered with a Device Option of LBM for latch status or LBMLCM for latch and keeper deadlocked status, and carries an SPDT switch device. Among other monitored strikes, the Dortronics 3300 Series includes a latch bolt sensing switch at 12/24VDC with a strike plate for ANSI 4-7/8 inch by 1-1/4 inch prep, the Hager 2945 is a fire rated rim exit strike with field selectable fail safe/fail secure and a latchbolt monitor, and the Camden CX-ED1799L-8 is a Grade 1 dual monitor fire rated strike supplied with eight faceplates.
9) My opening has a surface vertical rod exit device. Will the SDC 55-B work on it?
The SDC 55-B is a mortise strike sized for cylindrical locksets, mortise locksets with or without deadbolts, and mortise exit devices in hollow metal frames. A surface vertical rod device latches at the top and bottom of the door rather than into the jamb, so it calls for a different strike: the HES Folger Adam 310-4-2 is a Grade 1 complete electric strike pac built for surface vertical rods. For a pair of doors, the Rockwood double door electric strike with a 3/4 keeper is a Grade 1 fire rated unit in the 310-1 Series.
10) I want to avoid cutting the frame. Is there an alternative to the SDC 55-B for a retrofit?
The SDC 55-B retrofits existing ANSI 4-7/8 inch strike prep with no centerline relocation required and uses an interchangeable faceplate for new or retrofit work. If the existing prep is not ANSI, the Locknetics NC450 US32D is a no cut electric strike, and the Camden CX-ED1689L-4 is a fire rated universal low profile strike supplied with four faceplates to cover varying existing cutouts.
11) My access control panel outputs AC power. Will the SDC 55-B accept it?
The SDC 55-B is a 12/24 VDC strike with field selectable dual voltage. For an AC supply, the Trine 2001 operates on 16-24VAC/DC, fail secure, with a 5-7/8 inch by 1-1/4 inch faceplate and up to 5/8 inch throw, and the Trine 004 runs on 8-16VAC, fail secure, with a 6-1/4 inch by 1-3/8 inch faceplate and up to 5/8 inch throw. Both Trine units are fire rated and fail secure only, so an AC opening that must unlock on power loss needs a different approach.
12) Is the SDC 55-B strong enough for a high traffic entrance that gets abused?
The numbers behind it: 2,500 lbs holding force, 70 ft-lbs dynamic strength, and 1,000,000 endurance cycles. Stainless steel components in a heavy cast housing and keeper. That is the class of strike for a school corridor, a hospital entry, or a multi-tenant lobby where the door gets pulled on all day. A light commercial unit like the Trine 001 Series is not in the same duty class.
13) What else could I use instead of the SDC 55-B for a 3/4 inch latchbolt on a fire rated opening?
Closest equivalents by throw and rating: the HES Folger Adam 310-1(X) strike body handles 1/2, 5/8 or 3/4 inch throw latchbolts and is fire rated Grade 1. The Von Duprin 6400 is a Grade 1 modular strike for mortise or cylindrical locks with a 3-hour UL 10C rating in fail-secure. The Securitron MUNL mortise unlatch strike is also fire rated Grade 1. Where the 55-B differs is that it takes deadbolts up to 1 inch throw and gives you both fail-safe and fail-secure in the same unit, while the Von Duprin 6400 and 6210 are fail-secure.
14) Can the SDC 55-B electric strike be used with a mortise lock that has a deadbolt?
Yes, and that is one of the reasons to pick it over a plain cylindrical strike. The 55-B is rated for cylindrical locksets, mortise locksets with or without deadbolts, and mortise exit devices, taking a 3/4 inch latchbolt and a deadbolt up to 1 inch throw. Keep in mind the strike only releases the latch, so a thrown deadbolt still has to be retracted by key or by the lever on the inside before the door opens under access control.
15) Do I need a separate handed version of the SDC 55-B for a left hand versus right hand door?
No, handing is not an ordering decision here. The 55-B is non-handed and includes horizontal alignment adjustment, so the same strike serves either swing and you can dial the keeper in to the latch once the frame is prepped. Construction is corrosion and tamper resistant. What you do have to decide when ordering is the finish and whether you want latch monitoring (LBM) or latch plus keeper deadlock monitoring (LBMLCM).
16) Is there a lighter duty or lower cycle electric strike than the SDC 55-B for a low traffic interior door?
The SDC 55-B is a commercial strike tested to 1,000,000 endurance cycles with 2,500 lbs holding force and 70 ft-lbs dynamic strength. For lighter service, the Trine 001 Series is a fail-secure light commercial electric strike with a 5-7/8 inch by 1-1/4 inch faceplate, and the RCI 15BS is an economy electric strike for special offset latch entry with fail-secure operation. Neither the Trine 001 nor the RCI 15BS carries a fire rating, and both are fail-secure only rather than field reversible.
17) What is the difference between the SDC 55-B and the HES Folger Adam 310-1?
Both are heavy duty strikes for mortise and cylindrical applications. The SDC 55-B accepts a 3/4 inch throw latchbolt at a fixed capacity and runs on field selectable 12/24 VDC. The HES Folger Adam 310-1(X) is a Grade 1 fire rated electric strike body offered for 1/2 inch, 5/8 inch, or 3/4 inch throw latchbolts, so it spans a wider range of latch projections; it is supplied as a strike body, where the 55-B is a complete unit with an interchangeable faceplate that retrofits ANSI 4-7/8 inch strike prep without moving the centerline.
18) For a school or hospital standardizing on Grade 1 electric strikes, which units besides the SDC 55-B meet that grade?
The SDC 55-B is ANSI/BHMA A156.31 Grade 1 certified along with UL 1034 and UL 10C. Other Grade 1 strikes include the Alarm Controls AES-100 heavy duty strike, the Von Duprin 4211 32D for cylindrical locks at 12/24 VDC field-selectable with a fire rating, the Von Duprin 6210 for mortise locks at 24 VDC fail-secure with UL 10C, the Securitron MUNL mortise unlatch strike which is fire rated, and the Camden CX-ED1410 and CX-ED1420 universal fire-rated Grade 1 strikes. Standardizing across a facility is usually a matter of matching frame type and monitoring options within that Grade 1 group.
19) Are the HES 1500 and 1600 direct substitutes for the SDC 55-B?
No. The SDC 55-B is a complete mortise electric strike with a heavy cast housing and keeper, field selectable fail-safe/fail-secure operation, and a 3/4 inch latch throw. The HES 1500 and HES 1600 items are electric strike accessories for their respective Grade 1 fire rated series, meaning replacement and add-on components rather than a strike that can be installed in place of the 55-B. If the goal is a full strike assembly, the Grade 1 fire rated Securitron MUNL mortise unlatch strike is the substitute to look at instead.
20) How do the Locknetics MS100 and MDS100 compare with the SDC 55-B for a heavy traffic mortise opening?
The SDC 55-B is a heavy duty mortise strike tested to 1,000,000 endurance cycles with 2,500 lbs holding force and 70 ft-lbs dynamic strength, in a 3/4 inch latch throw. The Locknetics MS100 US32D and MDS100 US32D are both heavy duty electric strikes, the MS100 in the MS Series and the MDS100 in the MDS Series, supplied in US32D satin stainless. The Locknetics CS450-32D is in the CS Series and is not designated heavy duty, which matters on a door cycling all day.
21) I need a strike that stays locked on power failure and nothing else. Is the SDC 55-B overkill?
The SDC 55-B is field selectable between fail-safe and fail-secure, so it covers both modes in one part number and can be reconfigured later if the opening changes. If the opening will only ever be fail-secure, the Von Duprin 6210 is a heavy duty Grade 1 mortise lock strike at 24 VDC fail-secure with UL 10C fire rating, and the Von Duprin 6400 32D is a Grade 1 modular fail-secure strike for mortise or cylindrical locks in satin stainless with a 3-hour UL 10C rating in fail-secure. Those are fixed-mode units, so a later switch to fail-safe would mean replacing the strike.
22) Will the SDC 55-B match the finishes on the rest of my doors?
Ten finishes are offered on the 55-B: 605 bright brass, 606 dull brass, 611 bright bronze, 612 dull bronze, 613 oil rubbed bronze, 625 bright chrome, 626 dull chrome, 629 bright stainless and 630 satin stainless steel. For a building standardized on satin chrome trim, 626 is the usual pick; 630 satin stainless is the common match on commercial hollow metal openings. Each finish is available with no monitoring, with LBM, or with LBMLCM.
How fast can I get the SDC 55-BQ delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the SDC 55-BQ come with a warranty?
Absolutely. The SDC 55-BQ is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the SDC 55-BQ?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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